package router

import (
	"fmt"
	"net/http"
	"path/filepath"

	"go.jolheiser.com/blog/post"
	"go.jolheiser.com/blog/static"

	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
	"github.com/rs/zerolog/log"
)

func New(blog *post.Blog) *chi.Mux {
	m := chi.NewMux()

	m.Use(middleware.Logger)
	m.Use(middleware.Recoverer)

	m.Get("/", indexHandler(blog))
	m.Route("/{post}", func(r chi.Router) {
		r.With(slashesMiddleware).Get("/", fileHandler(blog))
		r.Get("/{asset}", assetHandler(blog))
	})
	m.Route("/_", func(r chi.Router) {
		r.Get("/sakura.css", static.SakuraCSS)
	})

	return m
}

func indexHandler(blog *post.Blog) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if err := static.IndexTemplate.Execute(w, blog); err != nil {
			log.Error().Err(err).Msg("could not execute template")
		}
	}
}

func fileHandler(blog *post.Blog) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		postName := chi.URLParam(r, "post")
		p, ok := blog.Post(postName)
		if !ok {
			w.WriteHeader(http.StatusNotFound)
			return
		}

		if err := static.PostTemplate.Execute(w, p); err != nil {
			log.Error().Err(err).Msg("could not execute template")
		}
	}
}

func assetHandler(blog *post.Blog) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		postName := chi.URLParam(r, "post")
		p, ok := blog.Post(postName)
		if !ok {
			w.WriteHeader(http.StatusNotFound)
			return
		}

		assetName := chi.URLParam(r, "asset")
		apn := filepath.Join(filepath.Dir(p.Path), assetName)
		http.ServeFile(w, r, apn)
	}
}

func slashesMiddleware(next http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		var path string
		rctx := chi.RouteContext(r.Context())
		if rctx != nil && rctx.RoutePath != "" {
			path = rctx.RoutePath
		} else {
			path = r.URL.Path
		}
		if len(path) > 1 && path[len(path)-1] != '/' {
			path += "/"
			if r.URL.RawQuery != "" {
				path = fmt.Sprintf("%s?%s", path, r.URL.RawQuery)
			}
			redirectURL := fmt.Sprintf("//%s%s", r.Host, path)
			http.Redirect(w, r, redirectURL, 301)
			return
		}
		next.ServeHTTP(w, r)
	}
	return http.HandlerFunc(fn)
}