package handlers

import (
	"context"
	"strconv"

	"github.com/gofiber/fiber/v3"

	"knowfoolery/backend/shared/types"
	"knowfoolery/backend/services/game-session-service/internal/application/services"
	"knowfoolery/backend/services/game-session-service/internal/application/dtos"
)

// GameSessionHandler handles HTTP requests for game sessions
type GameSessionHandler struct {
	applicationService *services.GameSessionApplicationService
}

// NewGameSessionHandler creates a new game session handler
func NewGameSessionHandler(applicationService *services.GameSessionApplicationService) *GameSessionHandler {
	return &GameSessionHandler{
		applicationService: applicationService,
	}
}

// StartNewSession handles POST /sessions
func (h *GameSessionHandler) StartNewSession(c fiber.Ctx) error {
	var request dtos.StartSessionRequest
	if err := c.Bind().JSON(&request); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "invalid_request",
			"message": "Failed to parse request body",
			"details": err.Error(),
		})
	}

	// Get user ID from context (set by auth middleware)
	userID := c.Locals("userID").(types.UserID)
	request.UserID = userID

	ctx := context.Background()
	response, err := h.applicationService.StartNewSession(ctx, &request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.Status(fiber.StatusCreated).JSON(response)
}

// ResumeSession handles GET /sessions/:sessionId/resume
func (h *GameSessionHandler) ResumeSession(c fiber.Ctx) error {
	sessionIDStr := c.Params("sessionId")
	sessionID := types.GameSessionID(sessionIDStr)

	request := &dtos.ResumeSessionRequest{
		SessionID: sessionID,
	}

	ctx := context.Background()
	response, err := h.applicationService.ResumeSession(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// SubmitAnswer handles POST /sessions/:sessionId/questions/:questionId/answers
func (h *GameSessionHandler) SubmitAnswer(c fiber.Ctx) error {
	sessionIDStr := c.Params("sessionId")
	questionIDStr := c.Params("questionId")

	sessionID := types.GameSessionID(sessionIDStr)
	questionID := types.QuestionID(questionIDStr)

	var requestBody struct {
		PlayerAnswer string `json:"player_answer"`
		HintUsed     bool   `json:"hint_used"`
	}

	if err := c.Bind().JSON(&requestBody); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "invalid_request",
			"message": "Failed to parse request body",
			"details": err.Error(),
		})
	}

	request := &dtos.SubmitAnswerRequest{
		SessionID:    sessionID,
		QuestionID:   questionID,
		PlayerAnswer: requestBody.PlayerAnswer,
		HintUsed:     requestBody.HintUsed,
	}

	ctx := context.Background()
	response, err := h.applicationService.SubmitAnswer(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	if !response.Accepted {
		return c.Status(fiber.StatusBadRequest).JSON(response)
	}

	return c.JSON(response)
}

// RequestHint handles POST /sessions/:sessionId/questions/:questionId/hint
func (h *GameSessionHandler) RequestHint(c fiber.Ctx) error {
	sessionIDStr := c.Params("sessionId")
	questionIDStr := c.Params("questionId")

	sessionID := types.GameSessionID(sessionIDStr)
	questionID := types.QuestionID(questionIDStr)

	request := &dtos.RequestHintRequest{
		SessionID:  sessionID,
		QuestionID: questionID,
	}

	ctx := context.Background()
	response, err := h.applicationService.RequestHint(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// CompleteSession handles POST /sessions/:sessionId/complete
func (h *GameSessionHandler) CompleteSession(c fiber.Ctx) error {
	sessionIDStr := c.Params("sessionId")
	sessionID := types.GameSessionID(sessionIDStr)

	var requestBody struct {
		Reason string `json:"reason"`
	}

	if err := c.Bind().JSON(&requestBody); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "invalid_request",
			"message": "Failed to parse request body",
			"details": err.Error(),
		})
	}

	request := &dtos.CompleteSessionRequest{
		SessionID: sessionID,
		Reason:    requestBody.Reason,
	}

	ctx := context.Background()
	response, err := h.applicationService.CompleteSession(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// AbandonSession handles POST /sessions/:sessionId/abandon
func (h *GameSessionHandler) AbandonSession(c fiber.Ctx) error {
	sessionIDStr := c.Params("sessionId")
	sessionID := types.GameSessionID(sessionIDStr)

	request := &dtos.AbandonSessionRequest{
		SessionID: sessionID,
	}

	ctx := context.Background()
	response, err := h.applicationService.AbandonSession(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// GetSessionStatus handles GET /sessions/:sessionId
func (h *GameSessionHandler) GetSessionStatus(c fiber.Ctx) error {
	sessionIDStr := c.Params("sessionId")
	sessionID := types.GameSessionID(sessionIDStr)

	request := &dtos.GetSessionStatusRequest{
		SessionID: sessionID,
	}

	ctx := context.Background()
	response, err := h.applicationService.GetSessionStatus(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// GetUserSessions handles GET /users/:userId/sessions
func (h *GameSessionHandler) GetUserSessions(c fiber.Ctx) error {
	userIDStr := c.Params("userId")
	userID := types.UserID(userIDStr)

	// Parse query parameters
	limitStr := c.Query("limit", "20")
	offsetStr := c.Query("offset", "0")

	limit, err := strconv.Atoi(limitStr)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "invalid_parameter",
			"message": "Invalid limit parameter",
		})
	}

	offset, err := strconv.Atoi(offsetStr)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "invalid_parameter",
			"message": "Invalid offset parameter",
		})
	}

	request := &dtos.GetUserSessionsRequest{
		UserID: userID,
		Limit:  limit,
		Offset: offset,
	}

	ctx := context.Background()
	response, err := h.applicationService.GetUserSessions(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// GetActiveSession handles GET /users/:userId/sessions/active
func (h *GameSessionHandler) GetActiveSession(c fiber.Ctx) error {
	userIDStr := c.Params("userId")
	userID := types.UserID(userIDStr)

	request := &dtos.GetActiveSessionRequest{
		UserID: userID,
	}

	ctx := context.Background()
	response, err := h.applicationService.GetActiveSession(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// GetMyActiveSession handles GET /sessions/active (for authenticated user)
func (h *GameSessionHandler) GetMyActiveSession(c fiber.Ctx) error {
	// Get user ID from context (set by auth middleware)
	userID := c.Locals("userID").(types.UserID)

	request := &dtos.GetActiveSessionRequest{
		UserID: userID,
	}

	ctx := context.Background()
	response, err := h.applicationService.GetActiveSession(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// GetMySessions handles GET /sessions (for authenticated user)
func (h *GameSessionHandler) GetMySessions(c fiber.Ctx) error {
	// Get user ID from context (set by auth middleware)
	userID := c.Locals("userID").(types.UserID)

	// Parse query parameters
	limitStr := c.Query("limit", "20")
	offsetStr := c.Query("offset", "0")

	limit, err := strconv.Atoi(limitStr)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "invalid_parameter",
			"message": "Invalid limit parameter",
		})
	}

	offset, err := strconv.Atoi(offsetStr)
	if err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "invalid_parameter",
			"message": "Invalid offset parameter",
		})
	}

	request := &dtos.GetUserSessionsRequest{
		UserID: userID,
		Limit:  limit,
		Offset: offset,
	}

	ctx := context.Background()
	response, err := h.applicationService.GetUserSessions(ctx, request)
	if err != nil {
		return h.handleError(c, err)
	}

	return c.JSON(response)
}

// handleError handles application errors and converts them to HTTP responses
func (h *GameSessionHandler) handleError(c fiber.Ctx, err error) error {
	switch {
	case isValidationError(err):
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "validation_failed",
			"message": err.Error(),
		})
	
	case isNotFoundError(err):
		return c.Status(fiber.StatusNotFound).JSON(fiber.Map{
			"error":   "not_found",
			"message": err.Error(),
		})
	
	case isConflictError(err):
		return c.Status(fiber.StatusConflict).JSON(fiber.Map{
			"error":   "conflict",
			"message": err.Error(),
		})
	
	case isOperationNotAllowedError(err):
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
			"error":   "operation_not_allowed",
			"message": err.Error(),
		})
	
	default:
		// Log the internal error
		// logger.Error("Internal server error", "error", err)
		
		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
			"error":   "internal_server_error",
			"message": "An unexpected error occurred",
		})
	}
}

// Error type checking helper functions
func isValidationError(err error) bool {
	// Check if error is a validation error
	// This would depend on your error types implementation
	return false // Placeholder
}

func isNotFoundError(err error) bool {
	// Check if error is a not found error
	return false // Placeholder
}

func isConflictError(err error) bool {
	// Check if error is a conflict error (e.g., duplicate session)
	return false // Placeholder
}

func isOperationNotAllowedError(err error) bool {
	// Check if error is an operation not allowed error
	return false // Placeholder
}

// RegisterRoutes registers all the game session routes
func (h *GameSessionHandler) RegisterRoutes(app fiber.Router) {
	// Session management routes
	app.Post("/sessions", h.StartNewSession)
	app.Get("/sessions/active", h.GetMyActiveSession) 
	app.Get("/sessions", h.GetMySessions)
	app.Get("/sessions/:sessionId", h.GetSessionStatus)
	app.Get("/sessions/:sessionId/resume", h.ResumeSession)
	app.Post("/sessions/:sessionId/complete", h.CompleteSession)
	app.Post("/sessions/:sessionId/abandon", h.AbandonSession)

	// Answer and hint routes
	app.Post("/sessions/:sessionId/questions/:questionId/answers", h.SubmitAnswer)
	app.Post("/sessions/:sessionId/questions/:questionId/hint", h.RequestHint)

	// User-specific session routes (admin/public access)
	app.Get("/users/:userId/sessions", h.GetUserSessions)
	app.Get("/users/:userId/sessions/active", h.GetActiveSession)
}

// Health check handler
func (h *GameSessionHandler) HealthCheck(c fiber.Ctx) error {
	return c.JSON(fiber.Map{
		"service": "game-session-service",
		"status":  "healthy",
		"timestamp": types.NewTimestamp(),
	})
}

// RegisterHealthRoutes registers health check routes
func (h *GameSessionHandler) RegisterHealthRoutes(app fiber.Router) {
	app.Get("/health", h.HealthCheck)
}