// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package app

import (
	"context"
	"encoding/xml"
	"io"
	"strings"

	"git.stormux.org/storm/cthulhu/internal/config"
	"git.stormux.org/storm/cthulhu/internal/i3ipc"
	"git.stormux.org/storm/cthulhu/internal/lifecycle"
	"git.stormux.org/storm/cthulhu/internal/platform/xorg"
)

// i3Announcements owns presentation policy, never focus or accessibility state.
// The backend owns its connection, baseline, caches and reconnect lifetime.
type i3Announcements struct {
	live   *liveSettings
	output speechEnqueuer
}

func i3ModeName(name string, markup bool) string {
	if !markup {
		return strings.TrimSpace(name)
	}
	decoder := xml.NewDecoder(strings.NewReader("<mode>" + name + "</mode>"))
	var text strings.Builder
	for {
		token, err := decoder.Token()
		if err == io.EOF {
			break
		}
		if err != nil {
			return ""
		}
		if data, ok := token.(xml.CharData); ok {
			text.Write(data)
		}
	}
	return strings.TrimSpace(text.String())
}

func i3Message(event i3ipc.Event, settings config.ReadingSettings) string {
	var text string
	switch event.Kind {
	case i3ipc.Mode:
		if !settings.I3Modes {
			return ""
		}
		name := i3ModeName(event.Name, event.Markup)
		if name == "" {
			return ""
		}
		if name == "default" {
			return "Default mode"
		}
		return name + " mode"
	case i3ipc.Workspace:
		if settings.I3Workspaces && event.Name != "" {
			return "Workspace " + event.Name
		}
		return ""
	case i3ipc.Fullscreen:
		if !settings.I3WindowStates {
			return ""
		}
		text = "Fullscreen off"
		if event.Enabled {
			text = "Fullscreen on"
			if event.FullscreenMode == 2 {
				text = "Global fullscreen on"
			}
		}
	case i3ipc.Floating:
		if !settings.I3WindowStates {
			return ""
		}
		text = "Floating off"
		if event.Enabled {
			text = "Floating on"
		}
	case i3ipc.Urgent:
		if !settings.I3Urgency {
			return ""
		}
		text = "Urgent"
		if event.Window != "" {
			text += ": " + event.Window
		}
		if event.Workspace != "" {
			text += ", workspace " + event.Workspace
		}
		return text
	case i3ipc.MarkAdded, i3ipc.MarkRemoved:
		if !settings.I3Marks {
			return ""
		}
		text = "Mark added: " + event.Name
		if event.Kind == i3ipc.MarkRemoved {
			text = "Mark removed: " + event.Name
		}
	case i3ipc.WorkspaceMove:
		if !settings.I3WorkspaceMoves || event.Workspace == "" {
			return ""
		}
		text = "Moved to workspace " + event.Workspace
	default:
		return ""
	}
	if !event.Focused {
		name := event.Window
		if name == "" {
			name = "Window"
		}
		text = name + ": " + text
	}
	return text
}

func (controller i3Announcements) present(event i3ipc.Event) {
	settings := controller.live.Load()
	text := i3Message(event, settings.Reading)
	if text == "" {
		return
	}
	controller.output.Enqueue(speechRequest{Text: text, Role: "system", Cause: "i3-desktop", Append: true, BypassFocusGate: true, InterruptDuringHandoff: true})
}

func i3Service(controller i3Announcements) lifecycle.Service {
	var cancel context.CancelFunc
	var done chan struct{}
	return lifecycle.Service{Name: "i3 desktop", Start: func(ctx context.Context) error {
		ctx, cancel = context.WithCancel(ctx)
		done = make(chan struct{})
		go func() { defer close(done); i3ipc.Run(ctx, xorg.I3Socket, controller.present) }()
		return nil
	}, Stop: func(ctx context.Context) error {
		if cancel == nil {
			return nil
		}
		cancel()
		select {
		case <-done:
			return nil
		case <-ctx.Done():
			return ctx.Err()
		}
	}}
}