MM-10702 Moving plugins to use hashicorp go-plugin. (#8978)

* Moving plugins to use hashicorp go-plugin.

* Tweaks from feedback.

1 files changed, 112 insertions, 0 deletions

diff --git a/app/plugin_commands.go b/app/plugin_commands.go
new file mode 100644
index 000000000..0f361f410
--- /dev/null
+++ b/app/plugin_commands.go
@@ -0,0 +1,112 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package app
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/mattermost/mattermost-server/model"
+)
+
+type PluginCommand struct {
+	Command  *model.Command
+	PluginId string
+}
+
+func (a *App) RegisterPluginCommand(pluginId string, command *model.Command) error {
+	if command.Trigger == "" {
+		return fmt.Errorf("invalid command")
+	}
+
+	command = &model.Command{
+		Trigger:          strings.ToLower(command.Trigger),
+		TeamId:           command.TeamId,
+		AutoComplete:     command.AutoComplete,
+		AutoCompleteDesc: command.AutoCompleteDesc,
+		AutoCompleteHint: command.AutoCompleteHint,
+		DisplayName:      command.DisplayName,
+	}
+
+	a.pluginCommandsLock.Lock()
+	defer a.pluginCommandsLock.Unlock()
+
+	for _, pc := range a.pluginCommands {
+		if pc.Command.Trigger == command.Trigger && pc.Command.TeamId == command.TeamId {
+			if pc.PluginId == pluginId {
+				pc.Command = command
+				return nil
+			}
+		}
+	}
+
+	a.pluginCommands = append(a.pluginCommands, &PluginCommand{
+		Command:  command,
+		PluginId: pluginId,
+	})
+	return nil
+}
+
+func (a *App) UnregisterPluginCommand(pluginId, teamId, trigger string) {
+	trigger = strings.ToLower(trigger)
+
+	a.pluginCommandsLock.Lock()
+	defer a.pluginCommandsLock.Unlock()
+
+	var remaining []*PluginCommand
+	for _, pc := range a.pluginCommands {
+		if pc.Command.TeamId != teamId || pc.Command.Trigger != trigger {
+			remaining = append(remaining, pc)
+		}
+	}
+	a.pluginCommands = remaining
+}
+
+func (a *App) UnregisterPluginCommands(pluginId string) {
+	a.pluginCommandsLock.Lock()
+	defer a.pluginCommandsLock.Unlock()
+
+	var remaining []*PluginCommand
+	for _, pc := range a.pluginCommands {
+		if pc.PluginId != pluginId {
+			remaining = append(remaining, pc)
+		}
+	}
+	a.pluginCommands = remaining
+}
+
+func (a *App) PluginCommandsForTeam(teamId string) []*model.Command {
+	a.pluginCommandsLock.RLock()
+	defer a.pluginCommandsLock.RUnlock()
+
+	var commands []*model.Command
+	for _, pc := range a.pluginCommands {
+		if pc.Command.TeamId == "" || pc.Command.TeamId == teamId {
+			commands = append(commands, pc.Command)
+		}
+	}
+	return commands
+}
+
+func (a *App) ExecutePluginCommand(args *model.CommandArgs) (*model.Command, *model.CommandResponse, *model.AppError) {
+	parts := strings.Split(args.Command, " ")
+	trigger := parts[0][1:]
+	trigger = strings.ToLower(trigger)
+
+	a.pluginCommandsLock.RLock()
+	defer a.pluginCommandsLock.RUnlock()
+
+	for _, pc := range a.pluginCommands {
+		if (pc.Command.TeamId == "" || pc.Command.TeamId == args.TeamId) && pc.Command.Trigger == trigger {
+			pluginHooks, err := a.Plugins.HooksForPlugin(pc.PluginId)
+			if err != nil {
+				return pc.Command, nil, model.NewAppError("ExecutePluginCommand", "model.plugin_command.error.app_error", nil, "err="+err.Error(), http.StatusInternalServerError)
+			}
+			response, appErr := pluginHooks.ExecuteCommand(args)
+			return pc.Command, response, appErr
+		}
+	}
+	return nil, nil, nil
+}