package router

import (
	"encoding/json"
	"log"
	"net/http"
	"os"
	"time"

	"github.com/rede5/gohorsejobs/backend/internal/api/middleware"
	"github.com/rede5/gohorsejobs/backend/internal/database"
	"github.com/rede5/gohorsejobs/backend/internal/handlers"
	"github.com/rede5/gohorsejobs/backend/internal/infrastructure/persistence/postgres"
	"github.com/rede5/gohorsejobs/backend/internal/infrastructure/storage"
	"github.com/rede5/gohorsejobs/backend/internal/services"

	// Core Imports
	apiHandlers "github.com/rede5/gohorsejobs/backend/internal/api/handlers"
	authUC "github.com/rede5/gohorsejobs/backend/internal/core/usecases/auth"
	tenantUC "github.com/rede5/gohorsejobs/backend/internal/core/usecases/tenant"
	userUC "github.com/rede5/gohorsejobs/backend/internal/core/usecases/user"
	authInfra "github.com/rede5/gohorsejobs/backend/internal/infrastructure/auth"
	legacyMiddleware "github.com/rede5/gohorsejobs/backend/internal/middleware"

	// Admin Imports

	_ "github.com/rede5/gohorsejobs/backend/docs" // Import generated docs
	httpSwagger "github.com/swaggo/http-swagger/v2"
)

func NewRouter() http.Handler {
	mux := http.NewServeMux()

	// Initialize Services
	jobService := services.NewJobService(database.DB)
	applicationService := services.NewApplicationService(database.DB)

	// --- CORE ARCHITECTURE INITIALIZATION ---
	// Infrastructure
	// Infrastructure,
	userRepo := postgres.NewUserRepository(database.DB)
	companyRepo := postgres.NewCompanyRepository(database.DB)

	jwtSecret := os.Getenv("JWT_SECRET")
	if jwtSecret == "" {
		// Fallback for dev, but really should be in env
		jwtSecret = "default-dev-secret-do-not-use-in-prod"
	}

	authService := authInfra.NewJWTService(jwtSecret, "todai-jobs")

	// UseCases
	loginUC := authUC.NewLoginUseCase(userRepo, authService)
	registerCandidateUC := authUC.NewRegisterCandidateUseCase(userRepo, companyRepo, authService)
	createCompanyUC := tenantUC.NewCreateCompanyUseCase(companyRepo, userRepo, authService)
	listCompaniesUC := tenantUC.NewListCompaniesUseCase(companyRepo)
	createUserUC := userUC.NewCreateUserUseCase(userRepo, authService)
	listUsersUC := userUC.NewListUsersUseCase(userRepo)
	deleteUserUC := userUC.NewDeleteUserUseCase(userRepo)
	updateUserUC := userUC.NewUpdateUserUseCase(userRepo)

	// Handlers & Middleware
	auditService := services.NewAuditService(database.DB)
	notificationService := services.NewNotificationService(database.DB)
	ticketService := services.NewTicketService(database.DB)

	authMiddleware := middleware.NewMiddleware(authService)
	adminService := services.NewAdminService(database.DB)

	coreHandlers := apiHandlers.NewCoreHandlers(
		loginUC,
		registerCandidateUC,
		createCompanyUC,
		createUserUC,
		listUsersUC,
		deleteUserUC,
		updateUserUC,
		listCompaniesUC,
		auditService,
		notificationService, // Added
		ticketService,       // Added
		adminService,        // Added for RBAC support
	)

	adminHandlers := apiHandlers.NewAdminHandlers(adminService, auditService, jobService)

	// Initialize Legacy Handlers
	jobHandler := handlers.NewJobHandler(jobService)
	applicationHandler := handlers.NewApplicationHandler(applicationService)

	// --- IP HELPER ---
	GetClientIP := func(r *http.Request) string {
		forwarded := r.Header.Get("X-Forwarded-For")
		if forwarded != "" {
			return forwarded
		}
		return r.RemoteAddr
	}

	// --- HEALTH CHECK ---
	mux.HandleFunc("GET /health", func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Header().Set("Content-Type", "text/plain")
		w.Write([]byte("OK"))
	})

	// --- ROOT ROUTE ---
	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/" {
			http.NotFound(w, r)
			return
		}

		response := map[string]interface{}{
			"message": "🐴 GoHorseJobs API is running!",
			"ip":      GetClientIP(r),
			"docs":    "/docs",
			"health":  "/health",
			"version": "1.0.0",
		}

		w.Header().Set("Content-Type", "application/json")
		if err := json.NewEncoder(w).Encode(response); err != nil {
			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		}
	})

	// --- CORE ROUTES ---
	// Public
	mux.HandleFunc("POST /api/v1/auth/login", coreHandlers.Login)
	mux.HandleFunc("POST /api/v1/auth/register", coreHandlers.RegisterCandidate)
	mux.HandleFunc("POST /api/v1/companies", coreHandlers.CreateCompany)
	// Public/Protected with RBAC (Smart Handler)
	mux.Handle("GET /api/v1/companies", authMiddleware.OptionalHeaderAuthGuard(http.HandlerFunc(coreHandlers.ListCompanies)))

	adminOnly := authMiddleware.RequireRoles("ADMIN", "SUPERADMIN", "admin", "superadmin")

	// Protected Core
	mux.Handle("POST /api/v1/users", authMiddleware.HeaderAuthGuard(http.HandlerFunc(coreHandlers.CreateUser)))
	mux.Handle("GET /api/v1/users", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(coreHandlers.ListUsers))))
	mux.Handle("PATCH /api/v1/users/{id}", authMiddleware.HeaderAuthGuard(http.HandlerFunc(coreHandlers.UpdateUser)))
	mux.Handle("DELETE /api/v1/users/{id}", authMiddleware.HeaderAuthGuard(http.HandlerFunc(coreHandlers.DeleteUser)))

	// Job Routes
	mux.HandleFunc("GET /api/v1/jobs", jobHandler.GetJobs)
	mux.Handle("POST /api/v1/jobs", authMiddleware.HeaderAuthGuard(http.HandlerFunc(jobHandler.CreateJob)))
	mux.HandleFunc("GET /api/v1/jobs/{id}", jobHandler.GetJobByID)
	mux.Handle("PUT /api/v1/jobs/{id}", authMiddleware.HeaderAuthGuard(http.HandlerFunc(jobHandler.UpdateJob)))
	mux.Handle("DELETE /api/v1/jobs/{id}", authMiddleware.HeaderAuthGuard(http.HandlerFunc(jobHandler.DeleteJob)))

	// --- ADMIN ROUTES (Consolidated to Standard Paths with RBAC) ---
	// /api/v1/admin/access/roles -> /api/v1/users/roles
	mux.Handle("GET /api/v1/users/roles", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.ListAccessRoles))))

	// /api/v1/admin/audit/logins -> /api/v1/audit/logins
	mux.Handle("GET /api/v1/audit/logins", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.ListLoginAudits))))

	// Public /api/v1/users/me (Authenticated)
	mux.Handle("GET /api/v1/users/me", authMiddleware.HeaderAuthGuard(http.HandlerFunc(coreHandlers.Me)))

	// /api/v1/admin/companies -> Handled by coreHandlers.ListCompanies (Smart Branching)
	// Needs to be wired with Optional Auth to support both Public and Admin.
	// I will create OptionalHeaderAuthGuard in middleware next.

	// /api/v1/admin/companies/{id} -> PATCH /api/v1/companies/{id}/status
	mux.Handle("PATCH /api/v1/companies/{id}/status", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.UpdateCompanyStatus))))

	// /api/v1/admin/jobs -> /api/v1/jobs?mode=admin (Need Smart Handler) or just separate path /api/v1/jobs/management?
	// User said "remove admin from ALL routes".
	// Maybe /api/v1/management/jobs?
	// Or just /api/v1/jobs (guarded)?
	// JobHandler.GetJobs is Public.
	// I will leave /api/v1/admin/jobs mapped to `GET /api/v1/jobs` for now (Collision).
	// OK, I will map it to `GET /api/v1/jobs/moderation` for clearer distinction without "admin" prefix?
	// Or simply `GET /api/v1/jobs` handle it?
	// Given safe constraints, `GET /api/v1/jobs/moderation` is safer than breaking public `GET /api/v1/jobs`.
	mux.Handle("GET /api/v1/jobs/moderation", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.ListJobs))))

	// /api/v1/admin/jobs/{id}/status
	mux.Handle("PATCH /api/v1/jobs/{id}/status", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.UpdateJobStatus))))

	// /api/v1/admin/jobs/{id}/duplicate -> /api/v1/jobs/{id}/duplicate
	mux.Handle("POST /api/v1/jobs/{id}/duplicate", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.DuplicateJob))))

	// /api/v1/admin/tags -> /api/v1/tags
	mux.Handle("GET /api/v1/tags", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.ListTags))))
	mux.Handle("POST /api/v1/tags", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.CreateTag))))
	mux.Handle("PATCH /api/v1/tags/{id}", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.UpdateTag))))

	// /api/v1/admin/candidates -> /api/v1/candidates
	mux.Handle("GET /api/v1/candidates", authMiddleware.HeaderAuthGuard(adminOnly(http.HandlerFunc(adminHandlers.ListCandidates))))

	// Notifications Route
	mux.Handle("GET /api/v1/notifications", authMiddleware.HeaderAuthGuard(http.HandlerFunc(coreHandlers.ListNotifications)))

	// Application Routes
	mux.HandleFunc("POST /api/v1/applications", applicationHandler.CreateApplication)
	mux.HandleFunc("GET /api/v1/applications", applicationHandler.GetApplications)
	mux.HandleFunc("GET /api/v1/applications/{id}", applicationHandler.GetApplicationByID)
	mux.HandleFunc("PUT /api/v1/applications/{id}/status", applicationHandler.UpdateApplicationStatus)

	// --- STORAGE ROUTES ---
	// Initialize S3 Storage (optional - graceful degradation if not configured)
	s3Storage, err := storage.NewS3Storage()
	if err != nil {
		log.Printf("Warning: S3 storage not available: %v", err)
	} else {
		storageHandler := handlers.NewStorageHandler(s3Storage)
		mux.Handle("POST /api/v1/storage/upload-url", authMiddleware.HeaderAuthGuard(http.HandlerFunc(storageHandler.GenerateUploadURL)))
		mux.Handle("POST /api/v1/storage/download-url", authMiddleware.HeaderAuthGuard(http.HandlerFunc(storageHandler.GenerateDownloadURL)))
		mux.Handle("DELETE /api/v1/storage/files", authMiddleware.HeaderAuthGuard(http.HandlerFunc(storageHandler.DeleteFile)))
		log.Println("S3 storage routes registered successfully")
	}

	// Swagger Route - available at /docs
	mux.HandleFunc("/docs/", httpSwagger.WrapHandler)

	// Apply middleware chain: Security Headers -> Rate Limiting -> CORS -> Router
	// Order matters: outer middleware runs first
	var handler http.Handler = mux
	handler = middleware.CORSMiddleware(handler)
	handler = legacyMiddleware.SanitizeMiddleware(handler)                    // Sanitize XSS from JSON bodies
	handler = legacyMiddleware.RateLimitMiddleware(100, time.Minute)(handler) // 100 req/min per IP
	handler = legacyMiddleware.SecurityHeadersMiddleware(handler)

	return handler
}