package hypr

import (
	"context"
	"errors"
	"fmt"
	"io"
	"io/fs"
	"os"
	"strconv"
	"strings"

	"git.milar.in/milarin/slices"
)

func GetClient(signature string) (*Client, error) {
	lockFilePath := fmt.Sprintf("/run/user/1000/hypr/%s/hyprland.lock", signature)

	file, err := os.Open(lockFilePath)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	data, err := io.ReadAll(file)
	if err != nil {
		return nil, err
	}

	lines := strings.Split(string(data), "\n")

	pid, err := strconv.Atoi(lines[0])
	if err != nil {
		return nil, err
	}

	return &Client{
		Signature:     signature,
		PID:           pid,
		WaylandSocket: lines[1],
	}, nil
}

func GetDefaultClient() (*Client, error) {
	signature, ok := os.LookupEnv("HYPRLAND_INSTANCE_SIGNATURE")
	if !ok {
		return nil, errors.New("default instance not found because HYPRLAND_INSTANCE_SIGNATURE is not set")
	}

	return GetClient(signature)
}

func GetClients() ([]*Client, error) {
	entries, err := os.ReadDir("/run/user/1000/hypr")
	if err != nil {
		return nil, err
	}

	entries = slices.Filter(entries, fs.DirEntry.IsDir)
	clients := make([]*Client, 0, len(entries))
	for _, entry := range entries {
		client, err := GetClient(entry.Name())
		if err != nil {
			fmt.Println(err)
			continue
		}
		clients = append(clients, client)
	}

	return clients, nil
}

func WaitForDefaultClient(ctx context.Context) (*Client, error) {
	signature, ok := os.LookupEnv("HYPRLAND_INSTANCE_SIGNATURE")
	if !ok {
		return nil, errors.New("default instance not found because HYPRLAND_INSTANCE_SIGNATURE is not set")
	}

	return WaitForClient(ctx, signature)
}

func WaitForClient(ctx context.Context, signature string) (*Client, error) {
	lockFilePath := fmt.Sprintf("/run/user/1000/hypr/%s/hyprland.lock", signature)

	lockFileExists := waitFor(ctx, func() bool {
		_, err := os.Stat(lockFilePath)
		return !errors.Is(err, os.ErrNotExist)
	})

	if !lockFileExists {
		return nil, errors.New("hyprland lock file not found")
	}

	client, err := GetClient(signature)
	if err != nil {
		return nil, err
	}

	if client.WaitUntilReachable(context.Background()) {
		return nil, errors.New("hyprland not reachable")
	}

	return client, nil
}