package lobby

import (
	"context"
	"fmt"
	"net/http"
	"strconv"
	"time"

	"github.com/ryanhamamura/games/connect4"
	"github.com/ryanhamamura/games/db/repository"
	lobbycomponents "github.com/ryanhamamura/games/features/lobby/components"
	"github.com/ryanhamamura/games/features/lobby/pages"
	appsessions "github.com/ryanhamamura/games/sessions"
	"github.com/ryanhamamura/games/snake"

	"github.com/alexedwards/scs/v2"
	"github.com/go-chi/chi/v5"
	"github.com/starfederation/datastar-go/datastar"
)

// HandleLobbyPage renders the main lobby page with active games for logged-in users.
func HandleLobbyPage(queries *repository.Queries, sessions *scs.SessionManager, snakeStore *snake.SnakeStore) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		userID := sessions.GetString(r.Context(), appsessions.KeyUserID)
		username := sessions.GetString(r.Context(), "username")
		isLoggedIn := userID != ""

		var userGames []lobbycomponents.GameListItem
		if isLoggedIn {
			ctx := context.Background()
			games, err := queries.GetUserActiveGames(ctx, &userID)
			if err == nil {
				for _, g := range games {
					isMyTurn := g.Status == 1 && g.CurrentTurn == g.MyColor
					opponentName := ""
					if g.OpponentNickname != nil {
						opponentName = *g.OpponentNickname
					}
					var lastPlayed time.Time
					if g.UpdatedAt != nil {
						lastPlayed = *g.UpdatedAt
					}
					userGames = append(userGames, lobbycomponents.GameListItem{
						ID:           g.ID,
						Status:       int(g.Status),
						OpponentName: opponentName,
						IsMyTurn:     isMyTurn,
						LastPlayed:   lastPlayed,
					})
				}
			}
		}

		var activeSnakeGames []pages.SnakeGameListItem
		for _, g := range snakeStore.ActiveGames() {
			statusLabel := "Waiting"
			if g.Status == snake.StatusCountdown {
				statusLabel = "Starting soon"
			}
			activeSnakeGames = append(activeSnakeGames, pages.SnakeGameListItem{
				ID:          g.ID,
				Width:       g.State.Width,
				Height:      g.State.Height,
				PlayerCount: g.PlayerCount(),
				StatusLabel: statusLabel,
			})
		}

		data := pages.LobbyData{
			IsLoggedIn:       isLoggedIn,
			Username:         username,
			UserGames:        userGames,
			ActiveSnakeGames: activeSnakeGames,
		}

		if err := pages.LobbyPage(data).Render(r.Context(), w); err != nil {
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
	}
}

// HandleCreateGame reads the nickname signal, creates a connect4 game, and redirects via SSE.
func HandleCreateGame(store *connect4.Store, sessions *scs.SessionManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		type Signals struct {
			Nickname string `json:"nickname"`
		}
		signals := &Signals{}
		if err := datastar.ReadSignals(r, signals); err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}

		if signals.Nickname == "" {
			return
		}

		sessions.Put(r.Context(), appsessions.KeyNickname, signals.Nickname)

		gi := store.Create()
		sse := datastar.NewSSE(w, r)
		sse.ExecuteScript(fmt.Sprintf("window.location.href='/games/%s'", gi.ID())) //nolint:errcheck
	}
}

// HandleDeleteGame deletes a connect4 game and redirects to the lobby.
func HandleDeleteGame(store *connect4.Store, sessions *scs.SessionManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		gameID := chi.URLParam(r, "id")
		if gameID == "" {
			http.Error(w, "missing game id", http.StatusBadRequest)
			return
		}

		store.Delete(gameID) //nolint:errcheck

		sse := datastar.NewSSE(w, r)
		sse.ExecuteScript("window.location.href='/'") //nolint:errcheck
	}
}

// HandleCreateSnakeGame reads nickname, grid preset, speed, and mode from the request,
// creates a snake game, and redirects via SSE.
func HandleCreateSnakeGame(snakeStore *snake.SnakeStore, sessions *scs.SessionManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		type Signals struct {
			Nickname      string `json:"nickname"`
			SelectedSpeed int    `json:"selectedSpeed"`
		}
		signals := &Signals{}
		if err := datastar.ReadSignals(r, signals); err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}

		if signals.Nickname == "" {
			return
		}

		sessions.Put(r.Context(), appsessions.KeyNickname, signals.Nickname)

		mode := snake.ModeMultiplayer
		if r.URL.Query().Get("mode") == "solo" {
			mode = snake.ModeSinglePlayer
		}

		presetIdx, _ := strconv.Atoi(r.URL.Query().Get("preset"))
		if presetIdx < 0 || presetIdx >= len(snake.GridPresets) {
			presetIdx = 0
		}
		preset := snake.GridPresets[presetIdx]

		speed := snake.DefaultSpeed
		if signals.SelectedSpeed >= 0 && signals.SelectedSpeed < len(snake.SpeedPresets) {
			speed = snake.SpeedPresets[signals.SelectedSpeed].Speed
		}

		si := snakeStore.Create(preset.Width, preset.Height, mode, speed)

		sse := datastar.NewSSE(w, r)
		sse.ExecuteScript(fmt.Sprintf("window.location.href='/snake/%s'", si.ID())) //nolint:errcheck
	}
}

// HandleLogout clears the session and redirects to the lobby.
func HandleLogout(sessions *scs.SessionManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := sessions.Destroy(r.Context()); err != nil {
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
			return
		}

		http.Redirect(w, r, "/", http.StatusSeeOther)
	}
}