package main

import (
	"bufio"
	"bytes"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"
)

// DesiredState represents a terminal window configuration from the file.
type DesiredState struct {
	Path      string
	Geometry  string // WIDTHxHEIGHT+X+Y
	Workspace string
}

// CurrentState represents an open window's properties from wmctrl.
type CurrentState struct {
	WindowID  string
	Workspace string
	Geometry  string // X,Y,Width,Height
	Path      string
}

func main() {
	// 1. Read the desired state from the config file.
	configFile := "/home/jcarr/go/src/gemini/xstartplacement.out"
	desiredStates, err := parseDesiredState(configFile)
	if err != nil {
		fmt.Printf("Error parsing config file: %v\n", err)
		return
	}

	// 2. Get the current state of all terminal windows.
	currentStates, err := getCurrentState()
	if err != nil {
		fmt.Printf("Error getting current window state: %v\n", err)
		return
	}

	// 3. Create a map of current windows for easy lookup.
	currentMap := make(map[string]bool)
	for _, window := range currentStates {
		// Normalize the path for comparison.
		currentMap[window.Path] = true
	}

	// 4. Compare desired state with current state and launch missing terminals.
	for _, desired := range desiredStates {
		if _, exists := currentMap[desired.Path]; !exists {
			fmt.Printf("Terminal for path '%s' not found. Launching...\n", desired.Path)
			launchTerminal(desired)
		} else {
			fmt.Printf("Terminal for path '%s' already exists. Skipping.\n", desired.Path)
		}
	}

	fmt.Println("Terminal synchronization complete.")
}

// launchTerminal launches and configures a new mate-terminal.
func launchTerminal(state DesiredState) {
	originalDir, _ := os.Getwd()
	if err := os.Chdir(state.Path); err != nil {
		fmt.Printf("Failed to change directory to %s: %v\n", state.Path, err)
		return
	}
	defer os.Chdir(originalDir)

	windowsBefore, err := getWindowList()
	if err != nil {
		fmt.Printf("Failed to get initial window list: %v\n", err)
		return
	}

	cmd := exec.Command("mate-terminal", "--geometry", state.Geometry)
	if err := cmd.Start(); err != nil {
		fmt.Printf("Failed to launch terminal for %s: %v\n", state.Path, err)
		return
	}

	var newWindowID string
	for i := 0; i < 10; i++ {
		time.Sleep(500 * time.Millisecond)
		windowsAfter, _ := getWindowList()
		newWindowID = findNewWindow(windowsBefore, windowsAfter)
		if newWindowID != "" {
			break
		}
	}

	if newWindowID == "" {
		fmt.Printf("Could not find new window for %s\n", state.Path)
		return
	}

	exec.Command("wmctrl", "-i", "-r", newWindowID, "-t", state.Workspace).Run()
	finalTitle := fmt.Sprintf("jcarr@framebook: %s", state.Path)
	exec.Command("wmctrl", "-i", "-r", newWindowID, "-T", finalTitle).Run()

	fmt.Printf("Successfully launched terminal for %s\n", state.Path)
}

// parseDesiredState reads the xstartplacement.out file.
func parseDesiredState(filePath string) ([]DesiredState, error) {
	file, err := os.Open(filePath)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	var states []DesiredState
	scanner := bufio.NewScanner(file)
	var currentState DesiredState
	homeDir, _ := os.UserHomeDir()

	for scanner.Scan() {
		line := scanner.Text()
		if strings.HasPrefix(line, "  Title: ") {
			title := strings.TrimSpace(strings.TrimPrefix(line, "  Title: "))
			parts := strings.SplitN(title, ": ", 2)
			if len(parts) == 2 {
				path := parts[1]
				if strings.HasPrefix(path, "~") {
					path = filepath.Join(homeDir, path[1:])
				}
				currentState.Path = path
			}
		} else if strings.HasPrefix(line, "  Geometry: ") {
			geomStr := strings.TrimSpace(strings.TrimPrefix(line, "  Geometry: "))
			var x, y, w, h string
			fmt.Sscanf(geomStr, "X=%s Y=%s Width=%s Height=%s", &x, &y, &w, &h)
			x = strings.TrimSuffix(x, ",")
			y = strings.TrimSuffix(y, ",")
			w = strings.TrimSuffix(w, ",")
			currentState.Geometry = fmt.Sprintf("%sx%s+%s+%s", w, h, x, y)
		} else if strings.HasPrefix(line, "  Workspace: ") {
			currentState.Workspace = strings.TrimSpace(strings.TrimPrefix(line, "  Workspace: "))
		} else if line == "---" {
			if currentState.Path != "" {
				states = append(states, currentState)
			}
			currentState = DesiredState{}
		}
	}
	if currentState.Path != "" {
		states = append(states, currentState)
	}
	return states, scanner.Err()
}

// getCurrentState gets all open mate-terminal windows.
func getCurrentState() ([]CurrentState, error) {
	cmd := exec.Command("wmctrl", "-lG")
	var out bytes.Buffer
	cmd.Stdout = &out
	if err := cmd.Run(); err != nil {
		return nil, err
	}

	var states []CurrentState
	scanner := bufio.NewScanner(&out)
	homeDir, _ := os.UserHomeDir()

	for scanner.Scan() {
		line := scanner.Text()
		if !strings.Contains(line, "jcarr@framebook") {
			continue
		}

		fields := strings.Fields(line)
		if len(fields) < 8 {
			continue
		}

		title := strings.Join(fields[7:], " ")
		parts := strings.SplitN(title, ": ", 2)
		if len(parts) != 2 {
			continue
		}

		path := parts[1]
		if strings.HasPrefix(path, "~") {
			path = filepath.Join(homeDir, path[1:])
		}

		states = append(states, CurrentState{
			WindowID:  fields[0],
			Workspace: fields[1],
			Geometry:  fmt.Sprintf("%s,%s,%s,%s", fields[2], fields[3], fields[4], fields[5]),
			Path:      path,
		})
	}
	return states, nil
}

// Helper functions
func getWindowList() (map[string]string, error) {
	cmd := exec.Command("wmctrl", "-l")
	var out bytes.Buffer
	cmd.Stdout = &out
	if err := cmd.Run(); err != nil {
		return nil, err
	}
	windows := make(map[string]string)
	scanner := bufio.NewScanner(&out)
	for scanner.Scan() {
		line := scanner.Text()
		fields := strings.Fields(line)
		if len(fields) > 0 {
			windows[fields[0]] = strings.Join(fields[3:], " ")
		}
	}
	return windows, nil
}

func findNewWindow(before, after map[string]string) string {
	for id := range after {
		if _, ok := before[id]; !ok {
			return id
		}
	}
	return ""
}