[geary/mjog/email-templates] Plugins: Add EmailTemplate plugin

[Michael Gratton <mjog src gnome org>]

commit 15025580e87da47a80210fcc301aae33a5ba6574
Author: Michael Gratton <mike vee net>
Date:   Mon Apr 20 23:51:55 2020 +1000

    Plugins: Add EmailTemplate plugin

 .../email-templates.plugin.desktop.in              |   4 +
 .../plugin/email-templates/email-templates.vala    | 331 +++++++++++++++++++++
 src/client/plugin/email-templates/meson.build      |  26 ++
 src/client/plugin/meson.build                      |   1 +
 4 files changed, 362 insertions(+)
---
diff --git a/src/client/plugin/email-templates/email-templates.plugin.desktop.in 
b/src/client/plugin/email-templates/email-templates.plugin.desktop.in
new file mode 100644
index 00000000..650e3c50
--- /dev/null
+++ b/src/client/plugin/email-templates/email-templates.plugin.desktop.in
@@ -0,0 +1,4 @@
+[Plugin]
+Module=email-templates
+Name=Email Templates
+Description=Create reusable templates for sending email
diff --git a/src/client/plugin/email-templates/email-templates.vala 
b/src/client/plugin/email-templates/email-templates.vala
new file mode 100644
index 00000000..5ae26488
--- /dev/null
+++ b/src/client/plugin/email-templates/email-templates.vala
@@ -0,0 +1,331 @@
+/*
+ * Copyright © 2020 Michael Gratton <mike vee net>.
+ *
+ * This software is licensed under the GNU Lesser General Public License
+ * (version 2.1 or later). See the COPYING file in this distribution.
+ */
+
+[ModuleInit]
+public void peas_register_types(TypeModule module) {
+    Peas.ObjectModule obj = module as Peas.ObjectModule;
+    obj.register_extension_type(
+        typeof(Plugin.PluginBase),
+        typeof(Plugin.EmailTemplates)
+    );
+}
+
+/**
+ * Manages UI for special folders.
+ */
+public class Plugin.EmailTemplates :
+    PluginBase, FolderExtension, EmailExtension {
+
+
+    // Translators: Templates folder name alternatives. Separate names
+    // using a vertical bar and put the most common localized name to
+    // the front for the default. English names do not need to be
+    // included.
+    private const string LOC_NAMES = _(
+        "Templates | Template Mail | Template Email | Template E-Mail"
+    );
+    // This must be identical to he above except without translation
+    private const string UNLOC_NAMES = (
+        "Templates | Template Mail | Template Email | Template E-Mail"
+    );
+
+
+    private const string ACTION_NEW = "new-template";
+    private const string ACTION_EDIT = "edit-template";
+    private const string ACTION_SEND = "send-template";
+
+    private const int INFO_BAR_PRIORITY = 0;
+
+
+    public FolderContext folders {
+        get; set construct;
+    }
+
+    public EmailContext email {
+        get; set construct;
+    }
+
+
+    private FolderStore? folder_store = null;
+    private EmailStore? email_store = null;
+
+    private GLib.SimpleAction? new_action = null;
+    private GLib.SimpleAction? edit_action = null;
+    private GLib.SimpleAction? send_action = null;
+
+    private Gee.Map<Folder,InfoBar> info_bars =
+        new Gee.HashMap<Folder,InfoBar>();
+
+    private Gee.List<string> folder_names = new Gee.ArrayList<string>();
+
+    private GLib.Cancellable cancellable = new GLib.Cancellable();
+
+
+    public override async void activate() throws GLib.Error {
+        Geary.iterate_array(UNLOC_NAMES.split("|")).map<string>(
+            (name) => name.strip()
+        ).add_all_to(this.folder_names);
+        Geary.iterate_array(LOC_NAMES.split("|")).map<string>(
+            (name) => name.strip()
+        ).add_all_to(this.folder_names);
+
+        this.folder_store = yield this.folders.get_folder_store();
+        this.folder_store.folders_available.connect(on_folders_available);
+        this.folder_store.folders_unavailable.connect(on_folders_unavailable);
+        this.folder_store.folders_type_changed.connect(on_folders_type_changed);
+        this.folder_store.folder_selected.connect(on_folder_selected);
+
+        this.email_store = yield this.email.get_email_store();
+        this.email_store.email_displayed.connect(on_email_displayed);
+
+        this.new_action = new GLib.SimpleAction(
+            ACTION_NEW, this.folder_store.folder_variant_type
+        );
+        this.new_action.activate.connect(on_new_activated);
+        this.plugin_application.register_action(this.new_action);
+
+        this.edit_action = new GLib.SimpleAction(
+            ACTION_EDIT, this.email_store.email_identifier_variant_type
+        );
+        this.edit_action.activate.connect(on_edit_activated);
+        this.plugin_application.register_action(this.edit_action);
+
+        this.send_action = new GLib.SimpleAction(
+            ACTION_SEND, this.email_store.email_identifier_variant_type
+        );
+        this.send_action.activate.connect(on_send_activated);
+        this.plugin_application.register_action(this.send_action);
+
+        foreach (var folder in this.folder_store.get_folders()) {
+            if (folder.display_name in this.folder_names) {
+                register_folder(folder);
+            }
+        }
+    }
+
+    public override async void deactivate(bool is_shutdown) throws GLib.Error {
+        // Take a copy of the keys so the collection doesn't asplode
+        // as it is being modified.
+        foreach (var folder in this.info_bars.keys.to_array()) {
+            unregister_folder(folder);
+        }
+        this.info_bars.clear();
+        this.folder_names.clear();
+
+        this.plugin_application.deregister_action(this.new_action);
+        this.new_action = null;
+
+        this.plugin_application.deregister_action(this.edit_action);
+        this.edit_action = null;
+
+        this.plugin_application.deregister_action(this.send_action);
+        this.send_action = null;
+
+        this.folder_store.folders_available.disconnect(on_folders_available);
+        this.folder_store.folders_unavailable.disconnect(on_folders_unavailable);
+        this.folder_store.folders_type_changed.disconnect(on_folders_type_changed);
+        this.folder_store.folder_selected.disconnect(on_folder_selected);
+        this.folder_store = null;
+
+        this.email_store.email_displayed.disconnect(on_email_displayed);
+        this.email_store = null;
+
+        this.cancellable.cancel();
+    }
+
+    private async void edit_email(Folder? target, EmailIdentifier? id, bool send) {
+        var account = (target != null) ? target.account : id.account;
+        try {
+            var composer = this.plugin_application.new_composer(account);
+            if (!send) {
+                var folder = target;
+                if (folder == null && id != null) {
+                    var containing = yield this.folder_store.list_containing_folders(
+                        id, this.cancellable
+                    );
+                    folder = containing.first_match(
+                        (f) => this.info_bars.has_key(f)
+                    );
+                }
+                composer.save_to_folder(folder);
+            }
+
+            if (id != null) {
+                yield composer.edit_email(id);
+            }
+            composer.show();
+        } catch (GLib.Error err) {
+            warning("Unable to construct composer: %s", err.message);
+        }
+    }
+
+    private void register_folder(Folder target) {
+        try {
+            this.folders.register_folder_used_as(
+                target,
+                // Translators: The name of the folder used to
+                // store email templates
+                _("Templates"),
+                "folder-templates-symbolic"
+            );
+            this.info_bars.set(
+                target,
+                new_templates_folder_info_bar(target)
+            );
+        } catch (GLib.Error err) {
+            warning(
+                "Failed to register %s as templates folder: %s",
+                target.persistent_id,
+                err.message
+            );
+        }
+    }
+
+    private void unregister_folder(Folder target) {
+        var info_bar = this.info_bars.get(target);
+        if (info_bar != null) {
+            try {
+                this.folders.unregister_folder_used_as(target);
+            } catch (GLib.Error err) {
+                warning(
+                    "Failed to unregister %s as templates folder: %s",
+                    target.persistent_id,
+                    err.message
+                );
+            }
+            this.folders.remove_folder_info_bar(target, info_bar);
+            this.info_bars.unset(target);
+        }
+    }
+
+    private void update_folder(Folder target) {
+        var info_bar = this.info_bars.get(target);
+        if (info_bar != null) {
+            this.folders.add_folder_info_bar(
+                target, info_bar, INFO_BAR_PRIORITY
+            );
+        }
+    }
+
+    private async void update_email(Email target) {
+        var containing = Gee.Collection.empty<Folder>();
+        try {
+            containing = yield this.folder_store.list_containing_folders(
+                target.identifier, this.cancellable
+            );
+        } catch (GLib.Error err) {
+            warning("Could not load folders for email: %s", err.message);
+        }
+        if (containing.any_match((f) => this.info_bars.has_key(f))) {
+            this.email.add_email_info_bar(
+                target.identifier,
+                new_template_email_info_bar(target.identifier),
+                INFO_BAR_PRIORITY
+            );
+        }
+    }
+
+    private InfoBar new_templates_folder_info_bar(Folder target) {
+        var bar = this.info_bars.get(target);
+        if (bar == null) {
+            bar = new InfoBar(target.display_name);
+            bar.primary_button = new Button(
+                // Translators: Info bar button label for creating a
+                // new email template
+                _("New"),
+                this.new_action,
+                target.to_variant()
+            );
+            this.info_bars.set(target, bar);
+        }
+        return bar;
+    }
+
+    private InfoBar new_template_email_info_bar(EmailIdentifier target) {
+        // Translators: Infobar status label for an email template
+        var bar = new InfoBar(_("Message template"));
+        bar.primary_button = new Button(
+            // Translators: Info bar button label for sending an
+            // email template
+            _("Send"),
+            this.send_action,
+            target.to_variant()
+        );
+        bar.secondary_buttons.add(
+            new Button(
+                // Translators: Info bar button label for editing an
+                // existing email template
+                _("Edit"),
+                this.edit_action,
+                target.to_variant()
+            )
+        );
+        return bar;
+    }
+
+    private void on_folders_available(Gee.Collection<Folder> available) {
+        foreach (var folder in available) {
+            if (folder.display_name in this.folder_names) {
+                register_folder(folder);
+            }
+        }
+    }
+
+    private void on_folders_unavailable(Gee.Collection<Folder> unavailable) {
+        foreach (var folder in unavailable) {
+            unregister_folder(folder);
+        }
+    }
+
+    private void on_folders_type_changed(Gee.Collection<Folder> changed) {
+        foreach (var folder in changed) {
+            unregister_folder(folder);
+            if (folder.display_name in this.folder_names) {
+                register_folder(folder);
+            }
+            update_folder(folder);
+        }
+    }
+
+    private void on_folder_selected(Folder selected) {
+        update_folder(selected);
+    }
+
+    private void on_new_activated(GLib.Action action, GLib.Variant? target) {
+        if (this.folder_store != null && target != null) {
+            Folder? folder = this.folder_store.get_folder_from_variant(target);
+            if (folder != null) {
+                this.edit_email.begin(folder, null, false);
+            }
+        }
+    }
+
+    private void on_edit_activated(GLib.Action action, GLib.Variant? target) {
+        if (this.email_store != null && target != null) {
+            EmailIdentifier? id =
+                this.email_store.get_email_identifier_from_variant(target);
+            if (id != null) {
+                this.edit_email.begin(null, id, false);
+            }
+        }
+    }
+
+    private void on_send_activated(GLib.Action action, GLib.Variant? target) {
+        if (this.email_store != null && target != null) {
+            EmailIdentifier? id =
+                this.email_store.get_email_identifier_from_variant(target);
+            if (id != null) {
+                this.edit_email.begin(null, id, true);
+            }
+        }
+    }
+
+    private void on_email_displayed(Email email) {
+        this.update_email.begin(email);
+    }
+
+}
diff --git a/src/client/plugin/email-templates/meson.build b/src/client/plugin/email-templates/meson.build
new file mode 100644
index 00000000..56ef251f
--- /dev/null
+++ b/src/client/plugin/email-templates/meson.build
@@ -0,0 +1,26 @@
+
+plugin_name = 'email-templates'
+
+plugin_src = files(plugin_name + '.vala')
+plugin_data = plugin_name + plugin_data_suffix
+plugin_dest = plugins_dir / plugin_name
+
+shared_module(
+  plugin_name,
+  sources: plugin_src,
+  dependencies: plugin_dependencies,
+  include_directories: config_h_dir,
+  vala_args: geary_vala_args,
+  c_args: plugin_c_args,
+  install: true,
+  install_dir: plugin_dest
+)
+
+i18n.merge_file(
+  input: files(plugin_data + plugin_data_src_suffix),
+  output: plugin_data,
+  type: 'desktop',
+  po_dir: po_dir,
+  install: true,
+  install_dir: plugin_dest
+)
diff --git a/src/client/plugin/meson.build b/src/client/plugin/meson.build
index 33c5ece4..6197a5f0 100644
--- a/src/client/plugin/meson.build
+++ b/src/client/plugin/meson.build
@@ -28,6 +28,7 @@ plugin_data_src_suffix = '.desktop.in'
 plugin_data_suffix = '.plugin'
 
 subdir('desktop-notifications')
+subdir('email-templates')
 subdir('folder-highlight')
 subdir('messaging-menu')
 subdir('notification-badge')