package routers

import (
	"context"
	"fmt"
	"io"
	"io/fs"
	"net/http"
	"path/filepath"
	"strconv"

	"gitea.com/gitea/pr-deployer/pkgs/services"
	"gitea.com/gitea/pr-deployer/pkgs/settings"
	"golang.org/x/oauth2"

	"gitea.com/go-chi/session"
	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
	"github.com/google/go-github/v39/github"
	log "github.com/sirupsen/logrus"
	"github.com/unrolled/render"
)

var rnd *render.Render

type tmplFS struct {
	fs.FS
}

func (tfs tmplFS) Walk(root string, walkFn filepath.WalkFunc) error {
	return fs.WalkDir(tfs, root, func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		info, err := d.Info()
		return walkFn(path, info, err)
	})
}

func (tfs tmplFS) ReadFile(filename string) ([]byte, error) {
	f, err := tfs.Open(filename)
	if err != nil {
		return nil, err
	}
	defer f.Close()
	return io.ReadAll(f)
}

func convertFS(templateFS fs.FS) render.FileSystem {
	return tmplFS{templateFS}
}

func Web(publicFS, templateFS fs.FS) {
	rnd = render.New(render.Options{
		Directory:     ".",
		IsDevelopment: true,
		FileSystem:    convertFS(templateFS),
	})

	c := chi.NewRouter()
	c.Use(session.Sessioner())
	c.Use(middleware.Logger)

	c.Get("/", Home)
	c.Get("/callback", OAuth2Callback)
	c.Get("/prs", ListPRs)
	c.Post("/pr/{index}/run", RunPR)
	c.Post("/pr/{index}/stop", StopPR)
	c.Post("/webhook", Webhook)

	fs := http.StripPrefix("/public", http.FileServer(http.FS(publicFS)))

	c.Get("/public/*", func(w http.ResponseWriter, r *http.Request) {
		fs.ServeHTTP(w, r)
	})

	http.ListenAndServe(":3001", c)
}

func ListPRs(w http.ResponseWriter, r *http.Request) {
	sess := session.GetSession(r)
	pToken := sess.Get("token")
	if pToken == nil {
		http.Redirect(w, r, "/", 302)
		return
	}

	p, _ := strconv.Atoi(r.FormValue("p"))
	if p < 1 {
		p = 1
	}

	token := pToken.(*oauth2.Token)
	fmt.Printf("%#v\n", token)
	c, err := services.NewClient(token)
	if err != nil {
		log.Error(err)
		return
	}

	pulls, err := c.GetPullRequests(p)
	if err != nil {
		log.Error(err)
		return
	}

	user := sess.Get("user")

	if err := rnd.HTML(w, http.StatusOK, "pulls", map[string]interface{}{
		"pulls": pulls,
		"user":  user,
	}); err != nil {
		log.Error(err)
	}
}

func RunPR(w http.ResponseWriter, r *http.Request) {
	idx := chi.URLParam(r, "index")
	i, _ := strconv.Atoi(idx)
	if i <= 0 {
		log.Errorf("start failed: %s is not a valid index", idx)
		return
	}
	ctx := context.Background()

	sess := session.GetSession(r)
	pToken := sess.Get("token")
	if pToken == nil {
		http.Redirect(w, r, "/", 302)
		return
	}

	token := pToken.(*oauth2.Token)
	fmt.Printf("%#v\n", token)
	client, err := services.NewClient(token)
	if err != nil {
		log.Error(err)
		return
	}

	if err := services.UpdateAndStartPullRequest(ctx, client, i, ""); err != nil {
		log.Error(err)
	}
}

func StopPR(w http.ResponseWriter, r *http.Request) {
	idx := chi.URLParam(r, "index")
	i, _ := strconv.Atoi(idx)
	if i <= 0 {
		log.Error("stop failed")
		return
	}
	if err := services.StopPullRequest(i); err != nil {
		log.Error("stop failed")
	}
}

func Webhook(w http.ResponseWriter, r *http.Request) {
	payload, err := github.ValidatePayload(r, settings.WebhookSecretKey)
	if err != nil {
		log.Error(err)
		return
	}
	event, err := github.ParseWebHook(github.WebHookType(r), payload)
	if err != nil {
		log.Error(err)
		return
	}

	switch evt := event.(type) {
	case *github.PullRequestEvent:
		switch *evt.Action {
		case "synchronize":
			ctx := context.Background()
			// FIXME: get token
			client, err := services.NewClient(nil)
			if err != nil {
				log.Error(err)
				return
			}
			if err := services.UpdateAndStartPullRequest(ctx, client, *evt.Number, *evt.After); err != nil {
				log.Error(err)
			}
		default:
			log.Trace("pull request %d is %s", *evt.Number, *evt.Action)
		}

	default:
		log.Warn("received %v type event, ignored", event)
	}
}