package handler

import (
	"context"
	"omega-server/local/model"
	"omega-server/local/service"
	"strings"

	"github.com/gofiber/fiber/v2"
)

// GraphQLHandler handles GraphQL requests
type GraphQLHandler struct {
	membershipService *service.MembershipService
}

// NewGraphQLHandler creates a new GraphQL handler
func NewGraphQLHandler(membershipService *service.MembershipService) *GraphQLHandler {
	return &GraphQLHandler{
		membershipService: membershipService,
	}
}

// GraphQLRequest represents a GraphQL request
type GraphQLRequest struct {
	Query     string                 `json:"query"`
	Variables map[string]interface{} `json:"variables"`
}

// GraphQLResponse represents a GraphQL response
type GraphQLResponse struct {
	Data   interface{}    `json:"data,omitempty"`
	Errors []GraphQLError `json:"errors,omitempty"`
}

// GraphQLError represents a GraphQL error
type GraphQLError struct {
	Message string   `json:"message"`
	Path    []string `json:"path,omitempty"`
}

// Handle processes GraphQL requests
func (h *GraphQLHandler) Handle(c *fiber.Ctx) error {
	var req GraphQLRequest
	if err := c.BodyParser(&req); err != nil {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Invalid request body"}},
		})
	}

	// Basic query parsing and handling
	ctx := c.UserContext()

	// Simple query routing based on query string
	query := strings.TrimSpace(req.Query)

	switch {
	case strings.Contains(query, "mutation") && strings.Contains(query, "login"):
		return h.handleLogin(c, ctx, req)
	case strings.Contains(query, "mutation") && strings.Contains(query, "createUser"):
		return h.handleCreateUser(c, ctx, req)
	case strings.Contains(query, "mutation") && strings.Contains(query, "createProject"):
		return h.handleCreateProject(c, ctx, req)
	case strings.Contains(query, "mutation") && strings.Contains(query, "createTask"):
		return h.handleCreateTask(c, ctx, req)
	case strings.Contains(query, "query") && strings.Contains(query, "me"):
		return h.handleMe(c, ctx, req)
	case strings.Contains(query, "query") && strings.Contains(query, "users"):
		return h.handleUsers(c, ctx, req)
	case strings.Contains(query, "query") && strings.Contains(query, "projects"):
		return h.handleProjects(c, ctx, req)
	case strings.Contains(query, "query") && strings.Contains(query, "tasks"):
		return h.handleTasks(c, ctx, req)
	default:
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Query not supported"}},
		})
	}
}

// handleLogin handles login mutations
func (h *GraphQLHandler) handleLogin(c *fiber.Ctx, ctx context.Context, req GraphQLRequest) error {
	// Extract variables
	email, ok := req.Variables["email"].(string)
	if !ok {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Email is required"}},
		})
	}

	password, ok := req.Variables["password"].(string)
	if !ok {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Password is required"}},
		})
	}

	// Call service
	token, err := h.membershipService.Login(ctx, email, password)
	if err != nil {
		return c.Status(401).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Invalid credentials"}},
		})
	}

	// Mock user data for now
	userData := map[string]interface{}{
		"id":        "1",
		"email":     email,
		"fullName":  "User",
		"createdAt": "2024-01-01T00:00:00Z",
		"updatedAt": "2024-01-01T00:00:00Z",
	}

	response := map[string]interface{}{
		"login": map[string]interface{}{
			"token": token,
			"user":  userData,
		},
	}

	return c.JSON(GraphQLResponse{Data: response})
}

// handleCreateUser handles user creation mutations
func (h *GraphQLHandler) handleCreateUser(c *fiber.Ctx, ctx context.Context, req GraphQLRequest) error {
	// Extract variables
	email, ok := req.Variables["email"].(string)
	if !ok {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Email is required"}},
		})
	}

	password, ok := req.Variables["password"].(string)
	if !ok {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Password is required"}},
		})
	}

	fullName, ok := req.Variables["fullName"].(string)
	if !ok {
		fullName = ""
	}

	// Create domain model
	user := &model.User{
		Email:    email,
		FullName: fullName,
	}

	if err := user.SetPassword(password); err != nil {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: err.Error()}},
		})
	}

	// Call service
	createdUser, err := h.membershipService.CreateUser(ctx, user, []string{"user"})
	if err != nil {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: err.Error()}},
		})
	}

	// Convert user to response format
	userData := map[string]interface{}{
		"id":        createdUser.ID,
		"email":     createdUser.Email,
		"fullName":  createdUser.FullName,
		"createdAt": createdUser.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
		"updatedAt": createdUser.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
	}

	response := map[string]interface{}{
		"createUser": userData,
	}

	return c.JSON(GraphQLResponse{Data: response})
}

// handleMe handles me queries
func (h *GraphQLHandler) handleMe(c *fiber.Ctx, ctx context.Context, req GraphQLRequest) error {
	// This would typically extract user ID from JWT token
	// For now, return mock data
	userData := map[string]interface{}{
		"id":        "1",
		"email":     "admin@example.com",
		"fullName":  "System Administrator",
		"createdAt": "2024-01-01T00:00:00Z",
		"updatedAt": "2024-01-01T00:00:00Z",
	}

	response := map[string]interface{}{
		"me": userData,
	}

	return c.JSON(GraphQLResponse{Data: response})
}

// handleUsers handles users queries
func (h *GraphQLHandler) handleUsers(c *fiber.Ctx, ctx context.Context, req GraphQLRequest) error {
	// Call service
	users, err := h.membershipService.ListUsers(ctx)
	if err != nil {
		return c.Status(500).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Failed to fetch users"}},
		})
	}

	// Convert users to response format
	usersData := make([]map[string]interface{}, len(users))
	for i, user := range users {
		usersData[i] = map[string]interface{}{
			"id":        user.ID,
			"email":     user.Email,
			"fullName":  user.FullName,
			"createdAt": user.CreatedAt.Format("2006-01-02T15:04:05Z07:00"),
			"updatedAt": user.UpdatedAt.Format("2006-01-02T15:04:05Z07:00"),
		}
	}

	response := map[string]interface{}{
		"users": usersData,
	}

	return c.JSON(GraphQLResponse{Data: response})
}

// handleCreateProject handles project creation mutations
func (h *GraphQLHandler) handleCreateProject(c *fiber.Ctx, ctx context.Context, req GraphQLRequest) error {
	// Extract variables
	name, ok := req.Variables["name"].(string)
	if !ok {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Name is required"}},
		})
	}

	ownerId, ok := req.Variables["ownerId"].(string)
	if !ok {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Owner ID is required"}},
		})
	}

	description, _ := req.Variables["description"].(string)

	// Mock project data for now
	projectData := map[string]interface{}{
		"id":          "mock-project-id",
		"name":        name,
		"description": description,
		"ownerId":     ownerId,
		"createdAt":   "2024-01-01T00:00:00Z",
		"updatedAt":   "2024-01-01T00:00:00Z",
	}

	response := map[string]interface{}{
		"createProject": projectData,
	}

	return c.JSON(GraphQLResponse{Data: response})
}

// handleCreateTask handles task creation mutations
func (h *GraphQLHandler) handleCreateTask(c *fiber.Ctx, ctx context.Context, req GraphQLRequest) error {
	// Extract variables
	title, ok := req.Variables["title"].(string)
	if !ok {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Title is required"}},
		})
	}

	projectId, ok := req.Variables["projectId"].(string)
	if !ok {
		return c.Status(400).JSON(GraphQLResponse{
			Errors: []GraphQLError{{Message: "Project ID is required"}},
		})
	}

	description, _ := req.Variables["description"].(string)
	status, _ := req.Variables["status"].(string)
	if status == "" {
		status = "todo"
	}
	priority, _ := req.Variables["priority"].(string)
	if priority == "" {
		priority = "medium"
	}

	// Mock task data for now
	taskData := map[string]interface{}{
		"id":          "mock-task-id",
		"title":       title,
		"description": description,
		"status":      status,
		"priority":    priority,
		"projectId":   projectId,
		"createdAt":   "2024-01-01T00:00:00Z",
		"updatedAt":   "2024-01-01T00:00:00Z",
	}

	response := map[string]interface{}{
		"createTask": taskData,
	}

	return c.JSON(GraphQLResponse{Data: response})
}

// handleProjects handles projects queries
func (h *GraphQLHandler) handleProjects(c *fiber.Ctx, ctx context.Context, req GraphQLRequest) error {
	// Mock empty projects list for now
	response := map[string]interface{}{
		"projects": []interface{}{},
	}

	return c.JSON(GraphQLResponse{Data: response})
}

// handleTasks handles tasks queries
func (h *GraphQLHandler) handleTasks(c *fiber.Ctx, ctx context.Context, req GraphQLRequest) error {
	// Mock empty tasks list for now
	response := map[string]interface{}{
		"tasks": []interface{}{},
	}

	return c.JSON(GraphQLResponse{Data: response})
}

// GetSchema returns the GraphQL schema
func (h *GraphQLHandler) GetSchema() string {
	return `
# Core Types
type User {
  id: String!
  email: String!
  fullName: String
  createdAt: String!
  updatedAt: String!
}

type Project {
  id: String!
  name: String!
  description: String
  ownerId: String!
  createdAt: String!
  updatedAt: String!
}

type Task {
  id: String!
  title: String!
  description: String
  status: String!
  priority: String!
  projectId: String!
  createdAt: String!
  updatedAt: String!
}

# Input Types
input LoginInput {
  email: String!
  password: String!
}

input UserCreateInput {
  email: String!
  fullName: String!
  password: String!
}

input ProjectCreateInput {
  name: String!
  description: String
  ownerId: String!
}

input TaskCreateInput {
  title: String!
  description: String
  status: String
  priority: String
  projectId: String!
}

# Response Types
type AuthResponse {
  token: String!
  user: User!
}

type MessageResponse {
  message: String!
  success: Boolean!
}

# Queries
type Query {
  me: User!
  users: [User!]!
  user(id: String!): User
  projects: [Project!]!
  project(id: String!): Project
  tasks(projectId: String): [Task!]!
  task(id: String!): Task
}

# Mutations
type Mutation {
  login(input: LoginInput!): AuthResponse!
  createUser(input: UserCreateInput!): User!
  createProject(input: ProjectCreateInput!): Project!
  createTask(input: TaskCreateInput!): Task!
}
`
}