package server

import (
	"context"
	"encoding/json"
	"fmt"
	"html/template"
	"log/slog"
	"net/http"
	"path"
	"strconv"
	"strings"

	"github.com/angelbeltran/templater"

	"ruben/inventory2/internal/consts"
	"ruben/inventory2/internal/domains/accounts"
	"ruben/inventory2/internal/domains/authentication"
	etsy_platform "ruben/inventory2/internal/domains/platforms/etsy"
	"ruben/inventory2/internal/domains/raw_events"
	"ruben/inventory2/internal/server/middleware"
	"ruben/inventory2/internal/server/response"
	"ruben/inventory2/internal/server/router"
	"ruben/inventory2/internal/server/webhooks"
	etsy_webhooks "ruben/inventory2/internal/server/webhooks/etsy"
)

type Server struct {
	log *slog.Logger
	http.Handler
	contentDir     string
	templater      *templater.Templater
	rawEvents      *raw_events.Store
	accts          *accounts.Store
	etsy           *etsy_platform.Platform
	auth           *authentication.Authenticator
	authMiddleware *middleware.Auth
}

func NewServer(
	ctx context.Context,
	logger *slog.Logger,
	contentDir string,
	rawEvents *raw_events.Store,
	accts *accounts.Store,
	etsy *etsy_platform.Platform,
	auth *authentication.Authenticator,
) *Server {
	mux := router.NewMux(middleware.LogRequests(ctx, logger.WithGroup("request")))

	s := &Server{
		log:        logger,
		Handler:    mux,
		contentDir: contentDir,
		templater: templater.NewTemplater(
			contentDir+"/templates",
			func() template.FuncMap {
				return template.FuncMap{
					// paths
					"buildSitePath": func(parts ...any) string {
						strParts := make([]string, len(parts))
						for i, p := range parts {
							strParts[i] = fmt.Sprint(p)
						}

						// TODO: make "/site" dynamic somehow
						//return path.Join(append([]string{"/site"}, strParts...)...)
						return path.Join(strParts...)
					},
					"splitPath": func(p string) []string {
						if p == "" {
							return nil
						}
						return strings.Split(strings.TrimSuffix(strings.TrimPrefix(p, "/"), "/"), "/")
					},

					// params
					"addPathParam": func(k string, v any, args map[string]any) (map[string]any, error) {
						pathParams, ok := args["PathParams"].(map[string]string)
						if !ok {
							return nil, fmt.Errorf("PathParams no set are args: %v", args)
						}

						pathParams[k] = fmt.Sprint(v)

						return args, nil
					},

					// parsing
					"parseInt": func(s string) (int, error) {
						return strconv.Atoi(s)
					},
					"parseInt64": func(s string) (int64, error) {
						return strconv.ParseInt(s, 10, 64)
					},
					"parsePlatform": func(s string) (accounts.Platform, error) {
						return accounts.NewPlatform(s)
					},

					// arithmetic
					"addInt": func(a, b int) int {
						return a + b
					},
					"subInt": func(a, b int) int {
						return a - b
					},
					"multInt": func(a, b int) int {
						return a * b
					},

					// json
					"prettyPrintJSON": func(j json.RawMessage) string {
						b, err := json.MarshalIndent(j, " ", "")
						if err != nil {
							return string(j)
						}
						return string(b)
					},
				}
			},
		),
		rawEvents: rawEvents,
		accts:     accts,
		etsy:      etsy,
		auth:      auth,
		authMiddleware: middleware.NewAuth(
			auth,
			newLoginURL,
			accts,
		),
	}

	withAuth := func(fn response.HandlerFunc) response.HandlerFunc {
		return s.authMiddleware.AuthenticateAndAddIdentity(fn)
	}

	// login

	// TODO: consider a separate '/login or /auth' router
	mux.Handle("GET /login", s.loginPage)
	mux.Handle("GET /login/callback", s.loginCallback)
	mux.Handle("GET /logout", s.logoutPage)

	// TODO: consider a separate '/accounts' router
	// /accounts

	mux.Handle("POST /accounts", withAuth(s.createAccount))
	mux.Handle("POST /accounts/{acctID}/inventory/sync-groups/draft/listings", withAuth(s.createSyncGroupListingDraft))
	mux.Handle("PUT /accounts/{acctID}/inventory/sync-groups/draft/listings/{orderIndex}/shop", withAuth(s.setShopInSyncGroupListingDraft))
	mux.Handle("PUT /accounts/{acctID}/inventory/sync-groups/draft/listings/{orderIndex}/listing", withAuth(s.setListingInSyncGroupListingDraft))
	mux.Handle("DELETE /accounts/{acctID}/inventory/sync-groups/draft/listings/{orderIndex}", withAuth(s.deleteSyncGroupListingDraft))
	mux.Handle("POST /accounts/{acctID}/inventory/sync-groups", withAuth(s.saveNewSyncGroup))

	// TODO: consider a webhook separate router
	// webhooks
	webhookHandler := http.StripPrefix("/webhooks", webhooks.New(
		logger.WithGroup("webhooks"),
		rawEvents,
		etsy,
		webhooks.Config{
			Etsy: etsy_webhooks.Config{
				OAuthRedirectURIWithAcctIDParam: "/oauth/account/{acctID}/auth_code",
			},
		},
	))
	mux.Mux.Handle("GET /webhooks/", webhookHandler)
	mux.Mux.Handle("POST /webhooks/", webhookHandler)
	mux.Mux.Handle("PUT /webhooks/", webhookHandler)

	// TODO: consider a separate webpage router

	// webpage content

	// non-html content: scripts, styles, images, etc

	scfs := http.FileServer(http.Dir(contentDir + "/scripts"))
	mux.Mux.Handle("GET /scripts/", http.StripPrefix("/scripts", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "text/javascript")
		if path.Ext(r.URL.Path) == ".gz" {
			w.Header().Set("Content-Encoding", "gzip")
		}
		scfs.ServeHTTP(w, r)
	})))
	mux.Mux.Handle("GET /styles/", http.StripPrefix("/styles", http.FileServer(http.Dir(contentDir+"/styles"))))

	// html

	// non-authenticated
	mux.Handle("GET /{$}", s.authMiddleware.AddIdentity(s.serveTemplates))
	// authenticated
	mux.Handle("GET /", withAuth(s.serveTemplates))

	return s
}

func mapConstantErrorsToHTTPErrors(err error) error {
	cerr := err
	for cerr != nil {
		switch cerr {
		case consts.ErrNotFound:
			return response.NotFound()
		case consts.ErrConflict:
			return response.Conflict()
		}

		uerr, ok := cerr.(interface {
			Unwrap() error
		})
		if !ok {
			return err
		}

		cerr = uerr.Unwrap()
	}
	return err
}

func newRequestIDProvider(ctx context.Context) <-chan int {
	reqIDCh := make(chan int)

	go func() {
		defer close(reqIDCh)

		nextReqID := 1

		for {
			select {
			case reqIDCh <- nextReqID:
				nextReqID += 1
			case <-ctx.Done():
				return
			}
		}
	}()

	return reqIDCh
}