Improve the texcompile plugin to work on windows

Borrow code from the rxi/console implementation to reliably
run commands on windows. Ideally should be based on the new reproc
library but this has to be done.

Problems of the current implementation:

- the output of the commands is ignored including warning and error messages
- the exit code of the command process is ignored

As a modification from the previous version of the plugin we no longer use
environment variables but we rely on "config" variables.

1 files changed, 148 insertions, 21 deletions

diff --git a/plugins/texcompile.lua b/plugins/texcompile.lua
index 2f53513..517aa9b 100644
--- a/plugins/texcompile.lua
+++ b/plugins/texcompile.lua
@@ -1,44 +1,171 @@
 -- mod-version:2 -- lite-xl 2.0
 local core = require "core"
+local config = require "core.config"
 local command = require "core.command"
+local common = require "core.common"
 local keymap = require "core.keymap"
 
-command.add("core.docview", {
-  ["texcompile:tex-compile"] = function()
-    local av = core.active_view
+-- This code use an adaptation of the rxi/console plugin code to
+-- start commands.
+
+local pending_threads = {}
+local thread_active = false
 
--- User's home directory
-    local homedir = ""
+local function push_output(str, opt)
+  -- By default we just ignore the output of a command.
+  -- print(">>OUTPUT:", str)
+end
+
+local function read_file(filename, offset)
+  local fp = io.open(filename, "rb")
+  fp:seek("set", offset or 0)
+  local res = fp:read("*a")
+  fp:close()
+  return res
+end
+
+local function write_file(filename, text)
+  local fp = io.open(filename, "w")
+  fp:write(text)
+  fp:close()
+end
+
+local function init_opt(opt)
+  local res = {
+    command = "",
+    arguments = {},
+    on_complete = function() end,
+  }
+  for k, v in pairs(res) do
+    res[k] = opt[k] or v
+  end
+  return res
+end
 
+local files = {
+  script   = core.temp_filename(PLATFORM == "Windows" and ".bat"),
+  script2  = core.temp_filename(PLATFORM == "Windows" and ".bat"),
+  output   = core.temp_filename(),
+  complete = core.temp_filename(),
+}
+
+local function command_run(opt)
+  opt = init_opt(opt)
+
+  local function thread()
+    -- init script file(s)
+    local args_quoted = {}
+    for i, arg in ipairs(opt.arguments) do args_quoted[i] = string.format("%q", arg) end
+    local args_concat = table.concat(args_quoted, " ")
+    local working_dir = opt.working_dir or "."
     if PLATFORM == "Windows" then
-        homedir = os.getenv("USERPROFILE")
+      write_file(files.script, string.format("%s %s\n", opt.command, args_concat))
+      write_file(files.script2, string.format([[
+        @echo off
+        cd %q
+        call %q >%q 2>&1
+        echo "" >%q
+        exit
+      ]], working_dir, files.script, files.output, files.complete))
+      system.exec(string.format("call %q", files.script2))
+    else
+      write_file(files.script, string.format([[
+        cd %q
+        %s %s
+        touch %q
+      ]], working_dir, opt.command, args_concat, files.complete))
+      system.exec(string.format("bash %q >%q 2>&1", files.script, files.output))
+    end
+
+    -- checks output file for change and reads
+    local last_size = 0
+    local function check_output_file()
+      if PLATFORM == "Windows" then
+        local fp = io.open(files.output)
+        if fp then fp:close() end
+      end
+      local info = system.get_file_info(files.output)
+      if info and info.size > last_size then
+        local text = read_file(files.output, last_size)
+        push_output(text, opt)
+        last_size = info.size
+      end
+    end
+
+    -- read output file until we get a file indicating completion
+    while not system.get_file_info(files.complete) do
+      check_output_file()
+      coroutine.yield(0.1)
+    end
+    check_output_file()
+
+    -- clean up and finish
+    for _, file in pairs(files) do
+      os.remove(file)
+    end
+    opt.on_complete()
+
+    -- handle pending thread
+    local pending = table.remove(pending_threads, 1)
+    if pending then
+      core.add_thread(pending)
     else
-        homedir = os.getenv("HOME")
+      thread_active = false
     end
+  end
+
+  -- push/init thread
+  if thread_active then
+    table.insert(pending_threads, thread)
+  else
+    core.add_thread(thread)
+    thread_active = true
+  end
+end
 
--- The current (La)TeX file and path
+command.add("core.docview", {
+  ["texcompile:tex-compile"] = function()
+    local av = core.active_view
+
+    -- The current (La)TeX file and path
     local texname = av:get_name()
-    local texpath = av:get_filename()
-    texpath = string.gsub(texpath, '~', homedir)
-    texpath = string.gsub(texpath, texname, '')
+    local texpath = common.dirname(av:get_filename())
+
+    -- Add in your user's config file something like:
+    --
+    -- config.texcompile = {
+    --   latex_command = "pdflatex",
+    --   view_command = "evince",
+    -- }
+    --
+    -- On windows you may use the full path for the command like:
+    --
+    -- latex_command = [[c:\miktex\miktex\bin\x64\pdflatex.exe]],
 
--- LaTeX compiler - is there any provided by the environment
-    local texcmd = os.getenv("LITE_LATEX_COMPILER")
+    -- LaTeX compiler - is there any provided by the environment
+    local texcmd = config.texcompile and config.texcompile.latex_command
+    local viewcmd = config.texcompile and config.texcompile.view_command
 
-    if texcmd == nil then
+    if not texcmd then
         core.log("No LaTeX compiler found")
     else
         core.log("LaTeX compiler is %s, compiling %s", texcmd, texname)
 
-        system.exec(string.format("cd %q && %q %q", texpath, texcmd, texname))
-    end
+        command_run {
+          command = texcmd,
+          arguments = { texname },
+          working_dir = texpath,
+          on_complete = function() core.log("Tex compiling command terminated.") end
+        }
 
---    core.add_thread(function()
---      coroutine.yield(5)
---      os.remove(htmlfile)
---    end)
+        local pdfname = texname:gsub("%.tex$", ".pdf")
+        command_run {
+          command = viewcmd,
+          arguments = { pdfname },
+          working_dir = texpath
+        }
+    end
   end
 })
 
-
 keymap.add { ["ctrl+shift+t"] = "texcompile:tex-compile" }