// SPDX-License-Identifier: AGPL-3.0-or-later

// Package handler contains HTTP handlers for all web and API routes.
package handler

import (
	"context"
	"io/fs"
	"net/http"
	"time"

	"kode.naiv.no/olemd/favoritter/internal/config"
	"kode.naiv.no/olemd/favoritter/internal/middleware"
	"kode.naiv.no/olemd/favoritter/internal/render"
	"kode.naiv.no/olemd/favoritter/internal/store"
	"kode.naiv.no/olemd/favoritter/web"
)

// Deps bundles all dependencies injected into handlers.
type Deps struct {
	Config   *config.Config
	Users    *store.UserStore
	Sessions *store.SessionStore
	Settings *store.SettingsStore
	Faves          *store.FaveStore
	Tags           *store.TagStore
	SignupRequests *store.SignupRequestStore
	Renderer       *render.Renderer
}

// Handler holds all HTTP handler methods and their dependencies.
type Handler struct {
	deps        Deps
	rateLimiter *middleware.RateLimiter
}

// New creates a new Handler with the given dependencies.
func New(deps Deps) *Handler {
	return &Handler{
		deps:        deps,
		rateLimiter: middleware.NewRateLimiter(deps.Config.RateLimit),
	}
}

// RateLimiterCleanupLoop periodically evicts stale rate limiter entries.
func (h *Handler) RateLimiterCleanupLoop(ctx context.Context, interval time.Duration) {
	ticker := time.NewTicker(interval)
	defer ticker.Stop()
	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			h.rateLimiter.Cleanup()
		}
	}
}

// Routes registers all routes on a new ServeMux and returns it.
func (h *Handler) Routes() *http.ServeMux {
	mux := http.NewServeMux()

	// Static files (served from embedded filesystem).
	staticFS, err := fs.Sub(web.StaticFS, "static")
	if err != nil {
		panic("embedded static filesystem missing: " + err.Error())
	}
	mux.Handle("GET /static/", http.StripPrefix("/static/", http.FileServer(http.FS(staticFS))))

	// Uploaded images (served from the filesystem upload directory).
	mux.Handle("GET /uploads/", http.StripPrefix("/uploads/",
		http.FileServer(http.Dir(h.deps.Config.UploadDir))))

	// Health check.
	mux.HandleFunc("GET /health", h.handleHealth)

	// Auth routes (rate-limited).
	mux.Handle("POST /login", h.rateLimiter.Limit(http.HandlerFunc(h.handleLoginPost)))
	mux.Handle("POST /signup", h.rateLimiter.Limit(http.HandlerFunc(h.handleSignupPost)))

	mux.HandleFunc("GET /login", h.handleLoginGet)
	mux.HandleFunc("GET /signup", h.handleSignupGet)
	mux.HandleFunc("POST /logout", h.handleLogout)

	// Password reset (for must-reset-password flow).
	mux.HandleFunc("GET /reset-password", h.handleResetPasswordGet)
	mux.HandleFunc("POST /reset-password", h.handleResetPasswordPost)

	// Home page.
	mux.HandleFunc("GET /{$}", h.handleHome)

	// Faves — authenticated routes use requireLogin wrapper.
	requireLogin := middleware.RequireLogin(h.deps.Config.BasePath)
	mux.Handle("GET /faves", requireLogin(http.HandlerFunc(h.handleFaveList)))
	mux.Handle("GET /faves/new", requireLogin(http.HandlerFunc(h.handleFaveNew)))
	mux.Handle("POST /faves", requireLogin(http.HandlerFunc(h.handleFaveCreate)))
	mux.HandleFunc("GET /faves/{id}", h.handleFaveDetail)
	mux.Handle("GET /faves/{id}/edit", requireLogin(http.HandlerFunc(h.handleFaveEdit)))
	mux.Handle("POST /faves/{id}", requireLogin(http.HandlerFunc(h.handleFaveUpdate)))
	mux.Handle("DELETE /faves/{id}", requireLogin(http.HandlerFunc(h.handleFaveDelete)))

	// Tags.
	mux.HandleFunc("GET /tags/search", h.handleTagSearch)
	mux.HandleFunc("GET /tags/{name}", h.handleTagBrowse)

	// Profiles.
	mux.HandleFunc("GET /u/{username}", h.handlePublicProfile)

	// User settings (authenticated).
	mux.Handle("GET /settings", requireLogin(http.HandlerFunc(h.handleSettingsGet)))
	mux.Handle("POST /settings", requireLogin(http.HandlerFunc(h.handleSettingsPost)))
	mux.Handle("POST /settings/avatar", requireLogin(http.HandlerFunc(h.handleAvatarPost)))
	mux.Handle("POST /settings/password", requireLogin(http.HandlerFunc(h.handleSettingsPasswordPost)))

	// Feeds (public, no auth required).
	mux.HandleFunc("GET /feed.xml", h.handleFeedGlobal)
	mux.HandleFunc("GET /u/{username}/feed.xml", h.handleFeedUser)
	mux.HandleFunc("GET /tags/{name}/feed.xml", h.handleFeedTag)

	// Import/Export (authenticated).
	mux.Handle("GET /export", requireLogin(http.HandlerFunc(h.handleExportPage)))
	mux.Handle("GET /export/json", requireLogin(http.HandlerFunc(h.handleExportJSON)))
	mux.Handle("GET /export/csv", requireLogin(http.HandlerFunc(h.handleExportCSV)))
	mux.Handle("GET /import", requireLogin(http.HandlerFunc(h.handleImportPage)))
	mux.Handle("POST /import", requireLogin(http.HandlerFunc(h.handleImportPost)))

	// Admin panel (requires admin role).
	admin := func(hf http.HandlerFunc) http.Handler {
		return requireLogin(middleware.RequireAdmin(http.HandlerFunc(hf)))
	}
	mux.Handle("GET /admin", admin(h.handleAdminDashboard))
	mux.Handle("GET /admin/users", admin(h.handleAdminUsers))
	mux.Handle("POST /admin/users", admin(h.handleAdminCreateUser))
	mux.Handle("POST /admin/users/{id}/reset-password", admin(h.handleAdminResetPassword))
	mux.Handle("POST /admin/users/{id}/toggle-disabled", admin(h.handleAdminToggleDisabled))
	mux.Handle("GET /admin/tags", admin(h.handleAdminTags))
	mux.Handle("POST /admin/tags/{id}/rename", admin(h.handleAdminRenameTag))
	mux.Handle("POST /admin/tags/{id}/delete", admin(h.handleAdminDeleteTag))
	mux.Handle("GET /admin/signup-requests", admin(h.handleAdminSignupRequests))
	mux.Handle("POST /admin/signup-requests/{id}", admin(h.handleAdminSignupRequestAction))
	mux.Handle("GET /admin/settings", admin(h.handleAdminSettingsGet))
	mux.Handle("POST /admin/settings", admin(h.handleAdminSettingsPost))

	return mux
}