feat: i18n (#182)

* build: add vue-i18n dependency

* feat: add i18n plugin to vue project

* feat: use translations in play button

* feat: translate play view

* feat: translate menu items

* feat: translate local mods view

* feat: translate online mods view

* feat: translate mods menu

* feat: translate thunderstore mod card component

* fix: remove useless "this" keyword

* feat: translate settings view

* fix: remove leftover test invocation

* feat: add language selector component

* feat: using language selector updates interface's language

* feat: save language in persistent store on selector change

* feat: initialize lang on app launch

* refactor: move i18n code into App.mounted callback

* feat: update interface language on app launch

* feat: adjust language selection on language selector load

* fix: this.$root can't be null

* feat: translate store notifications

* fix: add missing parameter to english translation

* feat: translate "by" author keyword

* feat: translate repair window

* feat: translate repair window title

* docs: add some documentation regarding localization

* docs: explain how to add a new language

* feat: translate Northstar release canal selector elements

* docs: describe how to inject variable into translations

* feat: translate "info" word

* feat: translate popconfirm buttons

* fix: remove "this" keyword

* fix: save store when updating interface language

4 files changed, 79 insertions, 32 deletions

diff --git a/src-vue/src/components/LanguageSelector.vue b/src-vue/src/components/LanguageSelector.vue
new file mode 100644
index 00000000..c09f6c05
--- /dev/null
+++ b/src-vue/src/components/LanguageSelector.vue
@@ -0,0 +1,47 @@
+<template>
+    <el-select v-model="value" class="m-2" 
+        :placeholder="$t('settings.language_select')" size="large"
+        @change="onChange"
+    >
+        <el-option
+            v-for="item in options"
+            :key="item.value"
+            :label="item.label"
+            :value="item.value"
+        />
+  </el-select>
+</template>
+
+<script lang="ts">
+import { defineComponent } from 'vue';
+import { Store } from 'tauri-plugin-store-api';
+const persistentStore = new Store('flight-core-settings.json');
+
+export default defineComponent({
+    name: 'LanguageSelector',
+    data: () => ({
+        value: '',
+        options: [
+            {
+                value: 'en',
+                label: 'English'
+            },
+            {
+                value: 'fr',
+                label: 'Français'
+            }
+        ]
+    }),
+    mounted: async function() {
+        const lang: string = await persistentStore.get('lang') as string;
+        this.value = lang;
+    },
+    methods: {
+        async onChange(value: string) {
+            this.$root!.$i18n.locale = value;
+            persistentStore.set('lang', value);
+            await persistentStore.save();
+        }
+    }
+})
+</script>
diff --git a/src-vue/src/components/ModsMenu.vue b/src-vue/src/components/ModsMenu.vue
index 9b62fcfa..656c05a6 100644
--- a/src-vue/src/components/ModsMenu.vue
+++ b/src-vue/src/components/ModsMenu.vue
@@ -7,20 +7,20 @@
             <h5>Mods</h5>
             <el-menu-item index="1" @click="$emit('showLocalMods', true)">
                 <el-icon><Folder /></el-icon>
-                <span>Local</span>
+                <span>{{ $t('mods.menu.local') }}</span>
             </el-menu-item>
             <el-menu-item index="2" @click="$emit('showLocalMods', false)">
                 <el-icon><Connection /></el-icon>
-                <span>Online</span>
+                <span>{{ $t('mods.menu.online') }}</span>
             </el-menu-item>
 
             <!-- Search inputs -->
-            <h5>Filter</h5>
-            <el-input v-model="$store.state.search.searchValue" placeholder="Search" clearable />
+            <h5>{{ $t('mods.menu.filter') }}</h5>
+            <el-input v-model="$store.state.search.searchValue" :placeholder="$t('mods.menu.search')" clearable />
             <el-select
                 v-if="!showingLocalMods"
                 v-model="$store.state.search.sortValue" 
-                placeholder="Sort mods"
+                :placeholder="$t('mods.menu.sort_mods')"
             >
                 <el-option
                     v-for="item of sortValues"
@@ -33,7 +33,7 @@
                 v-if="!showingLocalMods"
                 v-model="$store.state.search.selectedCategories"
                 multiple
-                placeholder="Select categories"
+                :placeholder="$t('mods.menu.select_categories')"
             >
                 <el-option
                     v-for="item in $store.state.thunderstoreModsCategories"
@@ -66,7 +66,7 @@ export default defineComponent({
         sortValues(): {label: string, value: string}[] {
             return Object.keys(SortOptions).map((key: string) => ({
                 value: key,
-                label: Object.values(SortOptions)[Object.keys(SortOptions).indexOf(key)]
+                label: this.$t('mods.menu.sort.' + Object.values(SortOptions)[Object.keys(SortOptions).indexOf(key)])
             }));
         }
     }
diff --git a/src-vue/src/components/PlayButton.vue b/src-vue/src/components/PlayButton.vue
index 687f12a4..3efcc9f5 100644
--- a/src-vue/src/components/PlayButton.vue
+++ b/src-vue/src/components/PlayButton.vue
@@ -18,22 +18,22 @@ export default defineComponent({
         },
         playButtonLabel(): string {
             if (this.$store.state.northstar_is_running) {
-                return "Game is running";
+                return this.$t("play.button.northstar_is_running");
             }
 
             switch(this.$store.state.northstar_state) {
                 case NorthstarState.GAME_NOT_FOUND:
-                    return "Select Titanfall2 game folder";
+                    return this.$t("play.button.select_game_dir");
                 case NorthstarState.INSTALL:
-                    return "Install";
+                    return this.$t("play.button.install");
                 case NorthstarState.INSTALLING:
-                    return "Installing..."
+                    return this.$t("play.button.installing");
                 case NorthstarState.MUST_UPDATE:
-                    return "Update";
+                    return this.$t("play.button.update");
                 case NorthstarState.UPDATING:
-                    return "Updating...";
+                    return this.$t("play.button.updating");
                 case NorthstarState.READY_TO_PLAY:
-                    return "Launch game";
+                    return this.$t("play.button.ready_to_play");
 
                 default:
                     return "";
@@ -57,7 +57,7 @@ export default defineComponent({
                     options: [
                         {
                             value: ReleaseCanal.RELEASE_CANDIDATE,
-                            label: 'Northstar release candidate',
+                            label: this.$t('channels.names.NorthstarReleaseCandidate'),
                         },
                     ]
                 },
diff --git a/src-vue/src/components/ThunderstoreModCard.vue b/src-vue/src/components/ThunderstoreModCard.vue
index c9f6768c..b81ed03c 100644
--- a/src-vue/src/components/ThunderstoreModCard.vue
+++ b/src-vue/src/components/ThunderstoreModCard.vue
@@ -21,7 +21,7 @@
             <br/>
 
             <div class="name hide-text-overflow">{{ mod.name }}</div>
-            <div class="author hide-text-overflow">by {{ mod.owner }}</div>
+            <div class="author hide-text-overflow">{{ $t('mods.card.by') }} {{ mod.owner }}</div>
             <div class="desc">
                 {{ latestVersion.description }}
             </div>
@@ -33,7 +33,7 @@
                     :loading="isBeingInstalled || isBeingUpdated"
                     @click.stop="installMod(mod)"
                 >
-                    {{ modButtonText }}
+                    {{ $t(modButtonText) }}
                 </el-button>
 
                 <!-- Information dropdown menu -->
@@ -51,10 +51,10 @@
                     <template #dropdown>
                         <el-dropdown-menu>
                             <el-dropdown-item @click="openURL(mod.package_url)">
-                                More info
+                                {{ $t('mods.card.more_info') }}
                             </el-dropdown-item>
                             <el-dropdown-item  @click="deleteMod(mod)">
-                                Remove mod
+                                {{ $t('mods.card.remove') }}
                             </el-dropdown-item>
                         </el-dropdown-menu>
                     </template>
@@ -129,15 +129,15 @@ export default defineComponent({
         modButtonText(): string {
             switch (this.modStatus) {
                 case ThunderstoreModStatus.BEING_INSTALLED:
-                    return "Installing...";
+                    return "mods.card.button.being_installed";
                 case ThunderstoreModStatus.BEING_UPDATED:
-                    return "Updating...";
+                    return "mods.card.button.being_updated";
                 case ThunderstoreModStatus.INSTALLED:
-                    return "Installed";
+                    return "mods.card.button.installed";
                 case ThunderstoreModStatus.NOT_INSTALLED:
-                    return "Install";
+                    return "mods.card.button.install";
                 case ThunderstoreModStatus.OUTDATED:
-                    return "Update";
+                    return "mods.card.button.outdated";
             }
         },
 
@@ -200,11 +200,11 @@ export default defineComponent({
 
             // Show pop-up to confirm delete
             ElMessageBox.confirm(
-                'Delete Thunderstore mod?',
-                'Warning',
+                this.$t('mods.card.remove_dialog_text'),
+                this.$t('mods.card.remove_dialog_title'),
                 {
-                    confirmButtonText: 'OK',
-                    cancelButtonText: 'Cancel',
+                    confirmButtonText: this.$t('generic.yes'),
+                    cancelButtonText: this.$t('generic.cancel'),
                     type: 'warning',
                 }
             )
@@ -217,7 +217,7 @@ export default defineComponent({
                     await invoke("delete_thunderstore_mod", { gameInstall: game_install, thunderstoreModString: this.latestVersion.full_name })
                         .then((message) => {
                             ElNotification({
-                                title: `Removed ${mod.name}`,
+                                title: this.$t('mods.card.remove_success', {modName: mod.name}),
                                 message: message as string,
                                 type: 'success',
                                 position: 'bottom-right'
@@ -225,7 +225,7 @@ export default defineComponent({
                         })
                         .catch((error) => {
                             ElNotification({
-                                title: 'Error',
+                                title: this.$t('generic.error'),
                                 message: error,
                                 type: 'error',
                                 position: 'bottom-right'
@@ -255,7 +255,7 @@ export default defineComponent({
 
             await invoke("install_mod_caller", { gameInstall: game_install, thunderstoreModString: this.latestVersion.full_name }).then((message) => {
                 ElNotification({
-                    title: `Installed ${mod.name}`,
+                    title: this.$t('mods.card.install_success', {modName: mod.name}),
                     message: message as string,
                     type: 'success',
                     position: 'bottom-right'
@@ -263,7 +263,7 @@ export default defineComponent({
             })
                 .catch((error) => {
                     ElNotification({
-                        title: 'Error',
+                        title: this.$t('generic.error'),
                         message: error,
                         type: 'error',
                         position: 'bottom-right'