setmetatable(_G, { __index = function(t, k) if not rawget(t, k) then error("cannot get undefined global variable: " .. k, 2) end end, __newindex = function(t, k) error("cannot set global variable: " .. k, 2) end  })

-- Begin rxi JSON library.
local json = { _version = "0.1.2" }
local encode
local escape_char_map = {
  [ "\\" ] = "\\",
  [ "\"" ] = "\"",
  [ "\b" ] = "b",
  [ "\f" ] = "f",
  [ "\n" ] = "n",
  [ "\r" ] = "r",
  [ "\t" ] = "t",
}

local escape_char_map_inv = { [ "/" ] = "/" }
for k, v in pairs(escape_char_map) do
  escape_char_map_inv[v] = k
end


local function escape_char(c)
  return "\\" .. (escape_char_map[c] or string.format("u%04x", c:byte()))
end


local function encode_nil(val)
  return "null"
end


local function encode_table(val, stack)
  local res = {}
  stack = stack or {}

  -- Circular reference?
  if stack[val] then error("circular reference") end

  stack[val] = true

  if rawget(val, 1) ~= nil or next(val) == nil then
    -- Treat as array -- check keys are valid and it is not sparse
    local n = 0
    for k in pairs(val) do
      if type(k) ~= "number" then
        error("invalid table: mixed or invalid key types")
      end
      n = n + 1
    end
    if n ~= #val then
      error("invalid table: sparse array")
    end
    -- Encode
    for i, v in ipairs(val) do
      table.insert(res, encode(v, stack))
    end
    stack[val] = nil
    return "[" .. table.concat(res, ",") .. "]"

  else
    -- Treat as an object
    for k, v in pairs(val) do
      if type(k) ~= "string" then
        error("invalid table: mixed or invalid key types")
      end
      table.insert(res, encode(k, stack) .. ":" .. encode(v, stack))
    end
    stack[val] = nil
    return "{" .. table.concat(res, ",") .. "}"
  end
end


local function encode_string(val)
  return '"' .. val:gsub('[%z\1-\31\\"]', escape_char) .. '"'
end


local function encode_number(val)
  -- Check for NaN, -inf and inf
  if val ~= val or val <= -math.huge or val >= math.huge then
    error("unexpected number value '" .. tostring(val) .. "'")
  end
  return string.format("%.14g", val)
end


local type_func_map = {
  [ "nil"     ] = encode_nil,
  [ "table"   ] = encode_table,
  [ "string"  ] = encode_string,
  [ "number"  ] = encode_number,
  [ "boolean" ] = tostring,
}


encode = function(val, stack)
  local t = type(val)
  local f = type_func_map[t]
  if f then
    return f(val, stack)
  end
  error("unexpected type '" .. t .. "'")
end


function json.encode(val)
  return ( encode(val) )
end

local parse

local function create_set(...)
  local res = {}
  for i = 1, select("#", ...) do
    res[ select(i, ...) ] = true
  end
  return res
end

local space_chars   = create_set(" ", "\t", "\r", "\n")
local delim_chars   = create_set(" ", "\t", "\r", "\n", "]", "}", ",")
local escape_chars  = create_set("\\", "/", '"', "b", "f", "n", "r", "t", "u")
local literals      = create_set("true", "false", "null")

local literal_map = {
  [ "true"  ] = true,
  [ "false" ] = false,
  [ "null"  ] = nil,
}


local function next_char(str, idx, set, negate)
  for i = idx, #str do
    if set[str:sub(i, i)] ~= negate then
      return i
    end
  end
  return #str + 1
end


local function decode_error(str, idx, msg)
  local line_count = 1
  local col_count = 1
  for i = 1, idx - 1 do
    col_count = col_count + 1
    if str:sub(i, i) == "\n" then
      line_count = line_count + 1
      col_count = 1
    end
  end
  error( string.format("%s at line %d col %d", msg, line_count, col_count) )
end


local function codepoint_to_utf8(n)
  -- http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=iws-appendixa
  local f = math.floor
  if n <= 0x7f then
    return string.char(n)
  elseif n <= 0x7ff then
    return string.char(f(n / 64) + 192, n % 64 + 128)
  elseif n <= 0xffff then
    return string.char(f(n / 4096) + 224, f(n % 4096 / 64) + 128, n % 64 + 128)
  elseif n <= 0x10ffff then
    return string.char(f(n / 262144) + 240, f(n % 262144 / 4096) + 128,
                       f(n % 4096 / 64) + 128, n % 64 + 128)
  end
  error( string.format("invalid unicode codepoint '%x'", n) )
end


local function parse_unicode_escape(s)
  local n1 = tonumber( s:sub(1, 4),  16 )
  local n2 = tonumber( s:sub(7, 10), 16 )
   -- Surrogate pair?
  if n2 then
    return codepoint_to_utf8((n1 - 0xd800) * 0x400 + (n2 - 0xdc00) + 0x10000)
  else
    return codepoint_to_utf8(n1)
  end
end


local function parse_string(str, i)
  local res = ""
  local j = i + 1
  local k = j

  while j <= #str do
    local x = str:byte(j)

    if x < 32 then
      decode_error(str, j, "control character in string")

    elseif x == 92 then -- `\`: Escape
      res = res .. str:sub(k, j - 1)
      j = j + 1
      local c = str:sub(j, j)
      if c == "u" then
        local hex = str:match("^[dD][89aAbB]%x%x\\u%x%x%x%x", j + 1)
                 or str:match("^%x%x%x%x", j + 1)
                 or decode_error(str, j - 1, "invalid unicode escape in string")
        res = res .. parse_unicode_escape(hex)
        j = j + #hex
      else
        if not escape_chars[c] then
          decode_error(str, j - 1, "invalid escape char '" .. c .. "' in string")
        end
        res = res .. escape_char_map_inv[c]
      end
      k = j + 1

    elseif x == 34 then -- `"`: End of string
      res = res .. str:sub(k, j - 1)
      return res, j + 1
    end

    j = j + 1
  end

  decode_error(str, i, "expected closing quote for string")
end


local function parse_number(str, i)
  local x = next_char(str, i, delim_chars)
  local s = str:sub(i, x - 1)
  local n = tonumber(s)
  if not n then
    decode_error(str, i, "invalid number '" .. s .. "'")
  end
  return n, x
end


local function parse_literal(str, i)
  local x = next_char(str, i, delim_chars)
  local word = str:sub(i, x - 1)
  if not literals[word] then
    decode_error(str, i, "invalid literal '" .. word .. "'")
  end
  return literal_map[word], x
end


local function parse_array(str, i)
  local res = {}
  local n = 1
  i = i + 1
  while 1 do
    local x
    i = next_char(str, i, space_chars, true)
    -- Empty / end of array?
    if str:sub(i, i) == "]" then
      i = i + 1
      break
    end
    -- Read token
    x, i = parse(str, i)
    res[n] = x
    n = n + 1
    -- Next token
    i = next_char(str, i, space_chars, true)
    local chr = str:sub(i, i)
    i = i + 1
    if chr == "]" then break end
    if chr ~= "," then decode_error(str, i, "expected ']' or ','") end
  end
  return res, i
end


local function parse_object(str, i)
  local res = {}
  i = i + 1
  while 1 do
    local key, val
    i = next_char(str, i, space_chars, true)
    -- Empty / end of object?
    if str:sub(i, i) == "}" then
      i = i + 1
      break
    end
    -- Read key
    if str:sub(i, i) ~= '"' then
      decode_error(str, i, "expected string for key")
    end
    key, i = parse(str, i)
    -- Read ':' delimiter
    i = next_char(str, i, space_chars, true)
    if str:sub(i, i) ~= ":" then
      decode_error(str, i, "expected ':' after key")
    end
    i = next_char(str, i + 1, space_chars, true)
    -- Read value
    val, i = parse(str, i)
    -- Set
    res[key] = val
    -- Next token
    i = next_char(str, i, space_chars, true)
    local chr = str:sub(i, i)
    i = i + 1
    if chr == "}" then break end
    if chr ~= "," then decode_error(str, i, "expected '}' or ','") end
  end
  return res, i
end


local char_func_map = {
  [ '"' ] = parse_string,
  [ "0" ] = parse_number,
  [ "1" ] = parse_number,
  [ "2" ] = parse_number,
  [ "3" ] = parse_number,
  [ "4" ] = parse_number,
  [ "5" ] = parse_number,
  [ "6" ] = parse_number,
  [ "7" ] = parse_number,
  [ "8" ] = parse_number,
  [ "9" ] = parse_number,
  [ "-" ] = parse_number,
  [ "t" ] = parse_literal,
  [ "f" ] = parse_literal,
  [ "n" ] = parse_literal,
  [ "[" ] = parse_array,
  [ "{" ] = parse_object,
}


parse = function(str, idx)
  local chr = str:sub(idx, idx)
  local f = char_func_map[chr]
  if f then
    return f(str, idx)
  end
  decode_error(str, idx, "unexpected character '" .. chr .. "'")
end


function json.decode(str)
  if type(str) ~= "string" then
    error("expected argument of type string, got " .. type(str))
  end
  local res, idx = parse(str, next_char(str, 1, space_chars, true))
  idx = next_char(str, idx, space_chars, true)
  if idx <= #str then
    decode_error(str, idx, "trailing garbage")
  end
  return res
end

-- End JSON library.

local common = {}

function common.rmrf(root)
  if not root or root == "" then return end
  local info = system.stat(root)
  if not info then return end
  if info.type == "file" then return os.remove(root) end
  for i,v in ipairs(system.ls(root)) do common.rmrf(root .. PATHSEP .. v) end
  system.rmdir(root)
end

function common.mkdirp(path)
  local stat = system.stat(path)
  if stat and stat.type == "dir" then return true end
  if stat and stat.type == "file" then error("path " .. path .. " exists") end
  local subdirs = {}
  while path and path ~= "" do
    system.mkdir(path)
    local updir, basedir = path:match("(.*)[/\\](.+)$")
    table.insert(subdirs, 1, basedir or path)
    path = updir
  end
  for _, dirname in ipairs(subdirs) do
    path = path and path .. PATHSEP .. dirname or dirname
    system.mkdir(path)
  end
end


function common.basename(path)
  local s = path:reverse():find("[/\\]")
  if not s then return path end
  return path:sub(#path - s + 2)
end


function common.dirname(path)
  local s = path:reverse():find(PATHSEP)
  if not s then return path end
  return path:sub(1, #path - s)
end


function common.merge(src, merge)
  for k, v in pairs(merge) do src[k] = v end
  return src
end


function common.map(list, predicate)
  local t = {}
  for i, v in ipairs(list) do table.insert(t, predicate(v)) end
  return t
end


function common.grep(list, predicate)
  local t = {}
  for i, v in ipairs(list) do if predicate(v) then table.insert(t, v) end end
  return t
end


function common.join(joiner, list)
  local s = ""
  for i, v in ipairs(list) do if i > 1 then s = s .. joiner .. v else s = v end end
  return s
end


function common.slice(t, i, l)
  local n = {}
  for j = i, l ~= nil and (i - l) or #t do
    table.insert(n, t[j])
  end
  return n
end

function common.copy(src, dst)
  local src_stat, dst_stat = system.stat(src), system.stat(dst)
  if not src_stat then error("can't find " .. src) end
  if dst_stat and dst_stat.type == "dir" then return common.copy(src, dst .. PATHSEP .. common.basename(src)) end
  if src_stat.type == "dir" then
    common.mkdirp(dst)
    for i, file in ipairs(system.ls(src)) do common.copy(src .. PATHSEP .. file, dst .. PATHSEP .. file) end
  else
    local src_io, err1 = io.open(src, "rb")
    if err1 then error("can't open for reading " .. src .. ": " .. err1) end
    local dst_io, err2 = io.open(dst, "wb")
    if err2 then error("can't open for writing " .. src .. ": " .. err2) end
    while true do
      local chunk = src_io:read(16*1024)
      if not chunk then break end
      dst_io:write(chunk)
    end
    dst_io:flush()
  end
end


local function is_commit_hash(hash)
  return #hash == 40 and not hash:find("[^a-z0-9]")
end


local HOME, USERDIR, CACHEDIR, JSON, VERBOSE, MOD_VERSION, QUIET, FORCE, AUTO_PULL_REMOTES, ARCH, ASSUME_YES, INSTALL_OPTIONAL, repositories

local actions, warnings = {}, {}
local function log_action(message)
  if JSON then table.insert(actions, message) end
  if not QUIET then io.stderr:write(message .. "\n") end
end
local function log_warning(message)
  if JSON then table.insert(warnings, message) end
  if not QUIET then io.stderr:write("warning: " .. message .. "\n") end
end
local function fatal_warning(message)
  if not FORCE then error(message .. "; use --force to override") else log_warning(message) end
end
local function prompt(message)
  io.stderr:write(message .. " [Y/n]: ")
  if ASSUME_YES then io.stderr:write("Y\n") return true end
  local response = io.stdin:read("*line")
  return not response:find("%S") or response:find("^%s*[yY]%s*$")
end


local function match_version(version, pattern)
  return not pattern or version == pattern
end

local function compare_version(a, b)
  return a and b and tonumber(a) < tonumber(b)
end

local function get_all_plugins()
  local t = {}
  for i,r in ipairs(repositories) do
    for j,p in ipairs(r.plugins) do
      table.insert(t, p)
    end
  end
  return t
end

local Plugin = {}
function Plugin.__index(self, idx) return rawget(self, idx) or Plugin[idx] end
function Plugin.new(repository, metadata)
  local type = metadata.type or "plugin"
  local folder = metadata.type == "library" and "libraries" or "plugins"
  if metadata.path then metadata.path = metadata.path:gsub("/", PATHSEP) end
  local self = setmetatable(common.merge({
    repository = repository,
    tags = {},
    type = type,
    remote = nil,
    path = nil,
    status = "available",
    version = "1.0",
    dependencies = {},
    local_path = repository.local_path .. PATHSEP .. (repository.commit or repository.branch) .. (metadata.path and (PATHSEP .. metadata.path:gsub("^/", "")) or ""),
    install_path = USERDIR .. PATHSEP .. folder .. PATHSEP .. (metadata.path and common.basename(metadata.path):gsub("%.lua$", "") or metadata.name),
  }, metadata), Plugin)
  -- Directory.
  self.organization = ((self.files and #self.files > 0) or self.remote or (not self.path and not self.url)) and "complex" or "singleton"
  if self.organization == "singleton" then self.install_path = self.install_path .. ".lua" end
  local stat = system.stat(self.install_path)
  local compatible = (not metadata.mod_version or tonumber(metadata.mod_version) == tonumber(MOD_VERSION))
  if stat and compatible then
    self.status = "installed"
    self.organization = stat.type == "dir" and "complex" or "singleton"
  else
    if not compatible then self.status = "incompatible" end
  end
  return self
end

function Plugin:is_installed()
  return self.status == "installed" or self.status == "upgradable"
end

function Plugin:is_incompatible(plugin)
  if self.dependencies[plugin.name] then
    if not match_version(plugin.version, dependencies[plugin.name]) then return true end
  end
  return false
end


local function get_plugin(name, version, filter)
  local candidates = {}
  filter = filter or {}
  for i,repo in ipairs(repositories) do
    for j,plugin in ipairs(repo.plugins) do
      if not version and plugin.provides then 
        for k, provides in ipairs(plugin.provides) do
          if provides == name then
            table.insert(candidates, plugin)
          end
        end
      end
      if plugin.name == name and match_version(plugin.version, version) then
        if (not filter.mod_version or not plugin.mod_version or tonumber(plugin.mod_version) == tonumber(filter.mod_version)) then
          table.insert(candidates, plugin)
        end
      end
    end
  end
  table.sort(candidates, function (a,b) return a.version < b.version end)
  return table.unpack(candidates)
end


function Plugin:get_compatibilities()
  local compatible_plugins = {}
  local incompatible_plugins = {}
  local installed_plugins = {}
  for i, repo in ipairs(repositories) do
    for j, plugin in ipairs(repo.plugins) do
      if plugin:is_installed() then
        table.insert(installed_plugins, plugin)
      end
    end
  end
  for plugin, v in pairs(self.dependencies) do
    local potential_plugins = { get_plugin(plugin, v.version, { mod_version = MOD_VERSION }) }
    local has_at_least_one = false
    local incomaptibilities = {}
    for i, potential_plugin in ipairs(potential_plugins) do
      for j, installed_plugin in ipairs(installed_plugins) do
        if installed_plugin:is_incompatible(potential_plugin) then
          table.insert(incomaptibilities, installed_plugin)
        end
      end
      if #incomaptibilities == 0 then
        if not compatible_plugins[plugin] or
          potential_plugin:is_installed() or
          (compare_version(compatible_plugins[plugin].version, potential_plugin.version) and not compatible_plugins[plugin]:is_installed())
        then
          compatible_plugins[plugin] = potential_plugin
        end
      else
        incompatible_plugins[plugin] = incompatibilities
      end
    end
  end
  return compatible_plugins, incompatible_plugins
end


local core_plugins = {
  autocomplete = true, autoreload = true, contextmenu = true, detectindent = true, drawwhitespace = true, language_c = true, language_cpp = true, language_css = true, language_html = true, language_js = true, language_lua = true, language_md = true, language_python = true, language_xml = true, lineguide = true, linewrapping = true, macro = true, projectsearch = true, quote = true, reflow = true, scale = true, tabularize = true, toolbarview = true, treeview = true, trimwhitespace = true, workspace = true
}

function Plugin:install(installing)
  if self.status == "installed" then error("plugin " .. self.name .. " is already installed") end
  local status, err = pcall(function()
    installing = installing or {}
    installing[self.name] = true
    local compatible, incompatible = self:get_compatibilities()
    for plugin, version in pairs(self.dependencies) do
      if incompatible[plugin] then error("can't install " .. self.name .. ": incompatible with " .. incompatible[plugin][1].name .. ":" .. incompatible[plugin][1].version) end
    end
    for plugin, v in pairs(self.dependencies) do
      if not core_plugins[plugin] and not compatible[plugin] then error("can't find dependency " .. plugin .. (v.version and (":" .. version) or "")) end
    end
    for plugin, v in pairs(self.dependencies) do
      if not core_plugins[plugin] and not compatible[plugin]:is_installed() then
        if installing[plugin] then
          error("circular dependency detected in " .. self.name .. ": requires " .. plugin .. " but, " .. plugin .. " requires " .. self.name)
        end
        if not v.optional or prompt(plugin .. " is an optional dependency of " .. self.name .. ". Should we install it?") then
          compatible[plugin]:install(installing)
        end
      end
    end
    common.mkdirp(common.dirname(self.install_path))
    if self.status == "upgradable" then 
      log_action("Upgrading " .. self.organization .. "plugin located at " .. self.local_path .. " to " .. self.install_path)
      common.rmrf(self.install_path) 
    else
      log_action("Installing " .. self.organization .. " plugin located at " .. self.local_path .. " to " .. self.install_path)
    end

    if self.organization == "complex" and self.path and system.stat(self.local_path).type ~= "dir" then common.mkdirp(self.install_path) end  
    if self.url then
      log_action("Downloading file " .. self.url .. "...")
      local path = self.install_path .. (self.organization == 'complex' and self.path and system.stat(self.local_path).type ~= "dir" and (PATHSEP .. "init.lua") or "")
      system.get(self.url, path)
      log_action("Downloaded file " .. self.url .. " to " .. path)
      if system.hash(path, "file") ~= self.checksum then fatal_warning("checksum doesn't match for " .. path) end
    elseif self.remote then
      log_action("Cloning repository " .. self.remote .. " into " .. self.install_path)
      common.mkdirp(self.install_path)
      local _, _, url, branch = self.remote:find("^(.*):(.*)$")
      system.init(self.install_path, url)
      system.reset(self.install_path, branch)
    else
      local path = self.install_path .. (self.organization == 'complex' and self.path and system.stat(self.local_path).type ~= "dir" and (PATHSEP .. "init.lua") or "")
      log_action("Copying " .. self.local_path .. " to " .. path)
      common.copy(self.local_path, path)
    end
    for i,file in ipairs(self.files or {}) do
      if not file.arch or file.arch == ARCH then
        if not file.checksum then error("requires a checksum") end
        local path = self.install_path .. PATHSEP .. (file.path or common.basename(file.url))
        log_action("Downloading file " .. file.url .. "...")
        system.get(file.url, path)
        log_action("Downloaded file " .. file.url .. " to " .. path)
        if system.hash(path, "file") ~= file.checksum then fatal_warning("checksum doesn't match for " .. path) end
      end
    end
  end)
  if not status then
    common.rmrf(self.install_path)
    error(err)
  end
end

function Plugin:depends_on(plugin)
  if self.dependencies[plugin] and self.dependencies[plugin].optional ~= false then return true end
  for i,v in ipairs(plugin.provides or {}) do if self.dependencies[v] and self.dependencies[v].optional ~= false then return true end end
  return false
end

function Plugin:uninstall()
  log_action("Uninstalling plugin located at " .. self.install_path)
  local incompatible_plugins = common.grep(get_all_plugins(), function(p) return p:is_installed() and p:depends_on(self) end)
  if #incompatible_plugins == 0 or prompt(self.name .. " is depended upon by " .. common.join(", ", common.map(incompatible_plugins, function(p) return p.name end)) .. ". Remove as well?") then
    for i,plugin in ipairs(incompatible_plugins) do 
      if not plugin:uninstall() then return false end
    end
    common.rmrf(self.install_path)
    return true
  end
  return false
end


local Repository = {}
function Repository.__index(self, idx) return rawget(self, idx) or Repository[idx] end
function Repository.new(hash)
  if not hash.remote then error("requires a remote") end
  if not hash.remote:find("^https?:") and not hash.remote:find("^file:") then error("only repositories with http and file transports are supported") end
  local self = setmetatable({ 
    commit = hash.commit,
    remote = hash.remote,
    branch = hash.branch,
    plugins = nil,
    local_path = CACHEDIR .. PATHSEP .. system.hash(hash.remote),
    last_retrieval = nil 
  }, Repository)
  if system.stat(self.local_path) and not self.commit and not self.branch then
    -- In the case where we don't have a branch, and don't have a commit, check for the presence of `master` and `main`.
    if system.stat(self.local_path .. PATHSEP .. "master") then
      self.branch = "master"
    elseif system.stat(self.local_path .. PATHSEP .. PATHSEP .. "main") then
      self.branch = "main"
    else
      error("can't find branch for " .. self.remote)
    end
  end
  return self
end

function Repository.url(url)
  local e = url:reverse():find(":")
  local s = e and (#url - e + 1)
  local remote, branch_or_commit = url:sub(1, s and (s-1) or #url), s and url:sub(s+1)
  if remote == "https" or remote == "file" then remote, branch_or_commit = url, nil end
  if branch_or_commit and is_commit_hash(branch_or_commit) then
    return Repository.new({ remote = remote, commit = branch_or_commit })
  end
  return Repository.new({ remote = remote, branch = branch_or_commit })
end

function Repository:parse_manifest(already_pulling)
  if self.manifest then return self.manifest, self.remotes end
  if system.stat(self.local_path) and system.stat(self.local_path .. PATHSEP .. (self.commit or self.branch)) then
    self.manifest_path = self.local_path .. PATHSEP .. (self.commit or self.branch) .. PATHSEP .. "manifest.json"
    if not system.stat(self.manifest_path) then self:generate_manifest() end
    self.manifest = json.decode(io.open(self.manifest_path, "rb"):read("*all")) 
    self.plugins = {}
    self.remotes = {}
    for i, metadata in ipairs(self.manifest["plugins"] or {}) do
      if metadata.remote then
        local _, _, url, branch_or_commit = metadata.remote:find("^(.-):?(.*)?$")
        if branch_or_commit and is_commit_hash(branch_or_commit) then
          repo = Repository.new({ remote = url, commit = branch_or_commit })
          table.insert(remotes, repo)
          table.insert(self.plugins, Plugin.new(self, metadata))
        else
          -- log_warning("plugin " .. metadata.name .. " specifies remote as source, but isn't a commit")
        end
      else
        table.insert(self.plugins, Plugin.new(self, metadata))
      end
    end
    for i, remote in ipairs(self.manifest["remotes"] or {}) do
      table.insert(self.remotes, Repository.url(remote))
    end
  end
  return self.manifest, self.remotes
end


-- in the cases where we don't have a manifest, assume generalized structure, take plugins folder, trawl through it, build manifest that way
-- assuming each .lua file under the `plugins` folder is a plugin. also parse the README, if present, and see if any of the plugins 
function Repository:generate_manifest()
  if not self.commit and not self.branch then error("requires an instantiation") end
  local path = self.local_path .. PATHSEP .. (self.commit or self.branch)
  local plugin_dir = system.stat(path .. PATHSEP .. "plugins") and PATHSEP .. "plugins" .. PATHSEP or PATHSEP
  local plugins, plugin_map = {}, {}
  if system.stat(path .. PATHSEP .. "README.md") then -- If there's a README, parse it for a table like in our primary repository.
    for line in io.lines(path .. PATHSEP .. "README.md") do
      local _, _, name, path, description = line:find("^%s*%|%s*%[`([%w_]+)%??.-`%]%((.-)%).-%|%s*(.-)%s*%|%s*$")
      if name then
        plugin_map[name] = { name = name, description = description, files = {} }
        if path:find("^http") then
          if path:find("%.lua") then
            plugin_map[name].url = path
            local file = system.get(path)
            plugin_map[name].checksum = system.hash(file)
          else
            plugin_map[name].remote = path
          end
        else
          plugin_map[name].path = path:gsub("%?.*$", "")
        end 
      end
    end
  end
  for i, file in ipairs(system.ls(path .. plugin_dir)) do
    if file:find("%.lua$") then
      local plugin = { description = nil, files = {}, name = common.basename(file):gsub("%.lua$", ""), dependencies = {}, mod_version = 3, version = "1.0", tags = {}, path = plugin_dir .. file  }
      for line in io.lines(path .. plugin_dir .. file) do
        local _, _, mod_version = line:find("%-%-.*mod%-version:%s*(%w+)")
        if mod_version then plugin.mod_version = mod_version end
        local _, _, required_plugin = line:find("require [\"']plugins.([%w_]+)")
        if required_plugin then if required_plugin ~= plugin.name then plugin.dependencies[required_plugin] = ">=1.0" end end
      end
      if plugin_map[plugin.name] then 
        plugin = common.merge(plugin, plugin_map[plugin.name])
        plugin_map[plugin.name].plugin = plugin 
      end
      table.insert(plugins, plugin)
    end
  end
  for k, v in pairs(plugin_map) do
    if not v.plugin then 
      table.insert(plugins, common.merge({ dependencies = {}, mod_version = 3, version = "1.0", tags = {} }, v))
    end
  end
  io.open(path .. PATHSEP .. "manifest.json", "wb"):write(json.encode({ plugins = plugins })):flush()
end

function Repository:add()
  -- If neither specified then pull onto `master`, and check the main branch name, and move if necessary.
  if not self.branch and not self.commit then 
    local path = self.local_path .. PATHSEP .. "master"
    common.mkdirp(path)
    log_action("Retrieving " .. self.remote .. ":master/main...")
    system.init(path, self.remote)
    system.fetch(path)
    if not pcall(system.reset, path, "refs/remotes/origin/master", "hard") then
      if pcall(system.reset, path, "refs/remotes/origin/main", "hard") then
        os.rename(path, self.local_path .. PATHSEP .. "main")
        self.branch = "main"
      else
        error("can't find master or main.")
      end
    else
      self.branch = "master"
    end
    log_action("Retrieved " .. self.remote .. ":master/main.")
  else
    local path = self.local_path .. PATHSEP .. (self.commit or self.branch)
    common.mkdirp(path)
    log_action("Retrieving " .. self.remote .. ":master/main...")
    system.init(path, self.remote)
    system.fetch(path)
    system.reset(path, self.commit or ("refs/remotes/origin/" .. self.branch), "hard")
    log_action("Retrieved " .. self.remote .. ":" .. (self.commit or self.branch) .. "...")
    self.manifest = nil
  end
  local manifest, remotes = self:parse_manifest()
  if AUTO_PULL_REMOTES then -- any remotes we don't have in our listing, call add, and add into the list
    for i, remote in ipairs(remotes) do 
      local has = common.grep(repositories, function(repo) return repo.remote == remote.remote and repo.branch == remote.branch and repo.commit == remote.comit end) > 0
      if #has == 0 then
        remote:add() 
        table.insert(repositories, remote)
      end
    end
  end
  return self
end


function Repository:update()
  local manifest, remotes = self:parse_manifest()
  if self.branch then
    local path = self.local_path .. PATHSEP .. self.branch
    system.fetch(path)
    system.reset(path, "refs/remotes/origin/" .. self.branch, "hard")
    log_action("Updated " .. self.remote .. ":" .. (self.commit or self.branch))
    self.manifest = nil
    manifest, remotes = self:parse_manifest()
  end
  if AUTO_PULL_REMOTES then -- any remotes we don't have in our listing, call add, and add into the list
    for i, remote in ipairs(remotes) do 
      local has = #common.grep(repositories, function(repo) return repo.remote == remote.remote and repo.branch == remote.branch and repo.commit == remote.comit end)
      if #has == 0 then
        remote:add() 
        table.insert(repositories, remote)
      end
    end
  end
end


function Repository:remove()
  common.rmrf(self.local_path .. PATHSEP .. (self.commit or self.branch))
  if #system.ls(self.local_path) == 0 then common.rmrf(self.local_path) end
end



local function get_repository(url)
  if not url then error("requires a repository url") end
  local r = Repository.url(url)
  for i,v in ipairs(repositories) do
    if v.remote == r.remote and v.branch == r.branch and v.commit == r.commit then return i, v end
  end
  return nil
end



local function lpm_repo_init()
  if not system.stat(CACHEDIR) then
    for i, repository in ipairs({ Repository.url("https://github.com/lite-xl/lite-xl-plugins.git:master"), Repository.url("https://github.com/lite-xl/lite-xl-plugins.git:2.1") }) do
      if not system.stat(repository.local_path) or not system.stat(repository.local_path .. PATHSEP .. (repository.commit or repository.branch)) then 
        common.mkdirp(repository.local_path)
        table.insert(repositories, repository:add())
      end
    end
  end
end


local function lpm_repo_add(...)
  for i, url in ipairs({ ... }) do
    local idx, repo = get_repository(url)
    if repo then -- if we're alreayd a repo, put this at the head of the resolution list
      table.remove(repositories, idx)
    else
      repo = Repository.url(url):add()
    end
    table.insert(repositories, 1, repo)
    repo:update()
  end
end


local function lpm_repo_rm(...)
  for i, url in ipairs({ ... }) do
    local idx, repo = get_repository(url)
    if not repo then error("cannot find repository " .. url) end
    table.remove(repositories, idx)
    repo:remove()
  end
end


local function lpm_repo_update(...)
  local t = { ... }
  if #t == 0 then table.insert(t, false) end
  for i, url in ipairs(t) do
    local repo = url and get_repository(url)
    for i,v in ipairs(repositories) do 
      if not repo or v == repo then 
        v:update() 
      end 
    end
  end
end


local function lpm_plugin_install(...)
  for i, identifier in ipairs({ ... }) do
    local s = identifier:find(":")
    local name, version = (s and identifier:sub(1, s-1) or identifier), (s and identifier:sub(s+1) or nil)
    if not name then error('unrecognized plugin identifier ' .. identifier) end
    local plugin = get_plugin(name, version, { mod_version = MOD_VERSION })
    if not plugin then error("can't find plugin " .. name .. " mod-version: " .. (MOD_VERSION or 'any')) end
    plugin:install()
  end
end


local function lpm_plugin_uninstall(...)
  for i, name in ipairs({ ... }) do
    local plugins = { get_plugin(name) }
    if #plugins == 0 then error("can't find plugin " .. name) end
    local installed_plugins = common.grep(plugins, function(plugin) return plugin:is_installed() end)
    if #installed_plugins == 0 then error("plugin " .. name .. " not installed") end
    for i, plugin in ipairs(installed_plugins) do plugin:uninstall() end
  end
end


local function lpm_repo_list() 
  if JSON then
    io.stdout:write(json.encode({ repositories = common.map(repositories, function(repo) return { remote = repo.remote, commit = repo.commit, branch = repo.branch, path = repo.local_path .. PATHSEP .. (repo.commit or repo.branch), remotes = common.map(repo.remotes or {}, function(r) return remote.remote .. ":" .. (remote.commit or remote.branch) end)  } end) }) .. "\n")
  else
    for i, repository in ipairs(repositories) do
      local _, remotes = repository:parse_manifest()
      if i ~= 0 then print("---------------------------") end
      print("Remote :  " .. repository.remote .. ":" .. (repository.commit or repository.branch))
      print("Path   :  " .. repository.local_path .. PATHSEP .. (repository.commit or repository.branch))
      print("Remotes:  " .. json.encode(common.map(repository.remotes or {}, function(r) return remote.remote .. ":" .. (remote.commit or remote.branch) end)))
    end
  end
end

local function lpm_plugin_list() 
  local result = { plugins = { } }
  for i,repo in ipairs(repositories) do
    if not repo.plugins then error("can't find plugins for repo " .. repo.remote .. ":" .. (repo.commit or repo.branch or "master")) end
    for j,plugin in ipairs(repo.plugins) do
      table.insert(result.plugins, {
        name = plugin.name,
        status = plugin.status,
        version = "" .. plugin.version,
        dependencies = plugin.dependencies,
        description = plugin.description,
        mod_version = plugin.mod_version,
        tags = plugin.tags,
        type = plugin.type,
        organization = plugin.organization,
        repository = repo.remote .. ":" .. (repo.commit or repo.branch)
      })
    end
  end
  if JSON then
    io.stdout:write(json.encode(result) .. "\n")
  else
    for i, plugin in ipairs(result.plugins) do
      if i ~= 0 then print("---------------------------") end
      print("Name:          " .. plugin.name)
      print("Version:       " .. plugin.version)
      print("Status:        " .. plugin.status)
      print("Type:          " .. plugin.type)
      print("Orgnization:   " .. plugin.organization)
      print("Repository:    " .. plugin.repository)
      print("Description:   " .. (plugin.description or ""))
      print("Mod-Version:   " .. (plugin.mod_version or "unknown"))
      print("Dependencies:  " .. json.encode(plugin.dependencies))
      print("Tags:          " .. common.join(", ", plugin.tags))
    end
  end
end

local function lpm_plugin_upgrade()
  for i,repo in ipairs(repositories) do
    if not repo.plugins then error("can't find plugins for repo " .. repo.remote .. ":" .. (repo.commit or repo.branch or "master")) end
    for j,plugin in ipairs(repo.plugins) do
      if plugin:is_installed() then
        local compatibles = get_plugin(plugin.name, ">" .. plugin.version)
        table.sort(compatibles, function(a, b) return compare_version(b.version, a.version) end)
        compatibles[1]:install()
      end
    end
  end
end

local function lpm_purge()
  log_action("Removed " .. CACHEDIR .. ".")
  common.rmrf(CACHEDIR)
end

local function parse_arguments(arguments, options)
  local args = {}
  local i = 1
  while i <= #arguments do
    local s,e, option, value = arguments[i]:find("%-%-([^=]+)=?(.*)")
    if s then
      local flag_type = options[option]
      if not flag_type then error("unknown flag --" .. option) end
      if flag_type == "flag" then
        args[option] = true
      elseif flag_type == "string" or flag_type == "number" then
        if not value then
          if i < #arguments then error("option " .. option .. " requires a " .. flag_type) end
          value = arguments[i+1]
          i = i + 1
        end
        if flag_type == "number" and tonumber(flag_type) == nil then error("option " .. option .. " should be a number") end
        args[option] = value
      end
    else
      table.insert(args, arguments[i])
    end
    i = i + 1
  end
  return args
end

local status = 0
local function error_handler(err)
  local s, e = err:find(":%d+")
  local message = e and err:sub(e + 3) or err
  if JSON then
    if VERBOSE then 
      io.stderr:write(json.encode({ error = err, actions = actions, warnings = warnings, traceback = debug.traceback() }) .. "\n")
    else
      io.stderr:write(json.encode({ error = message or err, actions = actions, warnings = warnings }) .. "\n")
    end
  else
    io.stderr:write((not VERBOSE and message or err) .. "\n")
    if VERBOSE then io.stderr:write(debug.traceback() .. "\n") end
  end
  status = -1
end

local function run_command(ARGS)
  if not ARGS[2]:find("%S") then return end
  if ARGS[2] == "repo" and ARGV[3] == "add" then lpm_repo_add(table.unpack(common.slice(ARGS, 4)))
  elseif ARGS[2] == "repo" and ARGS[3] == "rm" then lpm_repo_rm(table.unpack(common.slice(ARGS, 4)))
  elseif ARGS[2] == "add" then lpm_repo_add(table.unpack(common.slice(ARGS, 3)))
  elseif ARGS[2] == "rm" then lpm_repo_rm(table.unpack(common.slice(ARGS, 3)))
  elseif ARGS[2] == "update" then lpm_repo_update(table.unpack(common.slice(ARGS, 3)))
  elseif ARGS[2] == "repo" and ARGS[3] == "update" then lpm_repo_update(table.unpack(common.slice(ARGS, 4)))
  elseif ARGS[2] == "repo" and ARGS[3] == "list" then return lpm_repo_list()
  elseif ARGS[2] == "plugin" and ARGS[3] == "install" then lpm_plugin_install(table.unpack(common.slice(ARGS, 4)))
  elseif ARGS[2] == "plugin" and ARGS[3] == "uninstall" then lpm_plugin_uninstall(table.unpack(common.slice(ARGS, 4)))
  elseif ARGS[2] == "plugin" and ARGS[3] == "list" then return lpm_plugin_list(table.unpack(common.slice(ARGS, 4)))
  elseif ARGS[2] == "plugin" and ARGS[3] == "upgrade" then return lpm_plugin_upgrade(table.unpack(common.slice(ARGS, 4)))
  elseif ARGS[2] == "upgrade" then return lpm_plugin_upgrade(table.unpack(common.slice(ARGS, 3)))
  elseif ARGS[2] == "install" then lpm_plugin_install(table.unpack(common.slice(ARGS, 3)))
  elseif ARGS[2] == "uninstall" then lpm_plugin_uninstall(table.unpack(common.slice(ARGS, 3)))
  elseif ARGS[2] == "list" then return lpm_plugin_list(table.unpack(common.slice(ARGS, 3)))
  elseif ARGS[2] == "purge" then lpm_purge()
  else error("unknown command: " .. ARGS[2]) end
  if JSON then
    io.stdout:write(json.encode({ actions = actions, warnings = warnings }))
  end
end


xpcall(function()
  local ARGS = parse_arguments(ARGV, { 
    json = "flag", userdir = "string", cachedir = "string", version = "flag", verbose = "flag", 
    quiet = "flag", version = "string", ["mod-version"] = "string", remotes = "flag", help = "flag",
    remotes = "flag", ssl_certs = "string", force = "flag", arch = "string", ["assume-yes"] = "flag",
    ["install-optional"] = "flag"
  })
  if ARGS["version"] then
    io.stdout:write(VERSION .. "\n")
    return 0
  end
  if ARGS["help"] or #ARGS == 1 or ARGS[2] == "help" then
    io.stderr:write([[
Usage: lpm COMMAND [--json] [--userdir=directory] [--cachedir=directory]
  [--verbose] [--mod-version=3] [--quiet] [--version] [--help] [--remotes]
  [--ssl_certs=directory/file] [--force] [--arch=]] .. _G.ARCH .. [[]
  [--assume-yes] [--install-optional]

LPM is a package manager for `lite-xl`, written in C (and packed-in lua).

It's designed to install packages from our central github repository (and
affiliated repositories), directly into your lite-xl user directory. It can
be called independently, for from the lite-xl `plugin_manager` plugin.

LPM will always use https://github.com/lite-xl/lite-xl-plugins as its base
repository, if none are present, and the cache directory does't exist,
but others can be added, and this base one can be removed.

It has the following commands:

  lpm repo list                                      List all extant repos.
  lpm [repo] add <repository remote>                 Add a source repository.
    [...<repository remote>] 
  lpm [repo] rm <repository remote>                  Remove a source repository.
    [...<repository remote>]
  lpm [repo] update [<repository remote>]            Update all/the specified repositories.
    [...<repository remote>]        
  lpm [plugin] install <plugin name>[:<version>]     Install the specific plugins in question.
    [...<plugin name>:<version>]                     If the plugin is installed, upgrades it.
  lpm [plugin] uninstall <plugin name>               Uninstall the specific plugin.
    [...<plugin name>]
  lpm [plugin] list <repository remote>              List all/associated plugins.
    [...<repository remote>]    
  lpm [plugin] upgrade                               Upgrades all installed plugins to new version
                                                     if applicable.
  lpm purge                                          Completely purge all state for LPM.
  lpm -                                              Read these commands from stdin in an 
                                                     interactive print-eval loop.
  lpm help                                           Displays this help text.

Flags have the following effects:

  --json                         Performs all communication in JSON, rather than human-readable.
  --userdir=directory            Treats the specified directory as the lite-xl userdir.
                                 By default, this is set based on the normal lite-xl logic.
  --cachedir=directory           Sets the directory to store all repositories.
  --verbose                      Spits out more information, including intermediate steps to
                                 install and whatnot.
  --quiet                        Outputs nothing but explicit returning information from actions.
  --modversion=3                 Sets the mod version of lite-xl to install plugins against.
  --version                      Returns version information.
  --remotes                      Automatically adds any specified remotes in the repository to
                                 the end of the resolution list.
  --help                         Displays this help text.
  --ssl_certs                    Sets the SSL certificate store to specified location.
  --arch                         Overrides the inferred architecture (default: ]] .. _G.ARCH .. [[).
  --force                        Ignores checksum inconsitencies. Not recommended.
  --assume-yes                   Ignores any prompts, and automatically answers yes to all.
  --install-optional             On install, any dependencies marked as optional that can be installed
                                 will be installled.
]]
    )
    return 0
  end
  
  VERBOSE = ARGS["verbose"] or false
  JSON = ARGS["json"] or os.getenv("LPM_JSON")
  QUIET = ARGS["quiet"] or os.getenv("LPM_QUIET")
  FORCE = ARGS["force"]
  INSTALL_OPTIONAL = ARGS["install-optional"]
  ARCH = ARGS["arch"] or _G.ARCH
  ASSUME_YES = ARGS["assume-yes"] or FORCE
  MOD_VERSION = ARGS["mod-version"] or os.getenv("LPM_MODVERSION") or 3
  if MOD_VERSION == "any" then MOD_VERSION = nil end
  HOME = (os.getenv("USERPROFILE") or os.getenv("HOME")):gsub(PATHSEP .. "$", "")
  USERDIR = ARGS["userdir"] or os.getenv("LITE_USERDIR") or (os.getenv("XDG_CONFIG_HOME") and os.getenv("XDG_CONFIG_HOME") .. PATHSEP .. "lite-xl")
    or (HOME and (HOME .. PATHSEP .. '.config' .. PATHSEP .. 'lite-xl'))
  AUTO_PULL_REMOTES = ARGS["remotes"]
  if not system.stat(USERDIR) then error("can't find user directory " .. USERDIR) end
  CACHEDIR = ARGS["cachedir"] or os.getenv("LPM_CACHE") or USERDIR .. PATHSEP .. "lpm"

  if ARGS[2] == "purge" then return lpm_purge() end
  if ARGS["ssl_certs"] then 
    local stat = system.stat(ARGS["ssl_certs"])
    if not stat then error("can't find " .. ARGS["ssl_certs"]) end
    system.certs(stat.type, ARGS["ssl_certs"])
  elseif not os.getenv("SSL_CERT_DIR") and not os.getenv("SSL_CERT_FILE") then
    local paths = { -- https://serverfault.com/questions/62496/ssl-certificate-location-on-unix-linux#comment1155804_62500
      "/etc/ssl/certs/ca-certificates.crt",                -- Debian/Ubuntu/Gentoo etc.
      "/etc/pki/tls/certs/ca-bundle.crt",                  -- Fedora/RHEL 6
      "/etc/ssl/ca-bundle.pem",                            -- OpenSUSE
      "/etc/pki/tls/cacert.pem",                           -- OpenELEC
      "/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem", -- CentOS/RHEL 7
      "/etc/ssl/cert.pem",                                 -- Alpine Linux
      "/etc/ssl/certs",                                    -- SLES10/SLES11, https://golang.org/issue/12139
      "/system/etc/security/cacerts",                      -- Android
      "/usr/local/share/certs",                            -- FreeBSD
      "/etc/pki/tls/certs",                                -- Fedora/RHEL
      "/etc/openssl/certs",                                -- NetBSD
      "/var/ssl/certs",                                    -- AIX
    }
    for i, path in ipairs(paths) do
      local stat = system.stat(path) 
      if stat then 
        system.certs(stat.type, path) 
        break 
      end
    end
  end
  
  repositories = {}
  lpm_repo_init()
  repositories = {}
  for i, remote_hash in ipairs(system.ls(CACHEDIR)) do
    local remote
    for j, commit_or_branch in ipairs(system.ls(CACHEDIR .. PATHSEP .. remote_hash)) do
      if system.stat(CACHEDIR .. PATHSEP .. remote_hash .. PATHSEP  .. commit_or_branch .. PATHSEP .. ".git" .. PATHSEP .."config") then
        for line in io.lines(CACHEDIR .. PATHSEP .. remote_hash .. PATHSEP  .. commit_or_branch .. PATHSEP .. ".git" .. PATHSEP .."config") do
          local s,e = line:find("url = ") 
          if s then remote = line:sub(e+1) break end
        end
        if remote then
          table.insert(repositories, Repository.url(remote .. ":" .. commit_or_branch))
          repositories[#repositories]:parse_manifest()
        end
      end
    end
  end
  
  if ARGS[2] ~= '-' then
    run_command(ARGS)
  else
    while true do
      local line = io.stdin:read("*line")
      if line == "quit" or line == "exit" then return 0 end
      local args = { ARGS[1] }
      local s = 1
      while true do
        local a,e = line:find("%s+", s)
        table.insert(args, line:sub(s, a and (a - 1) or #line))
        if not e then break end
        s = e + 1
      end
      xpcall(function()
        run_command(args)
      end, error_handler)
      actions, warnings = {}, {}
    end
  end

end, error_handler)


return status