package registry

import (
	"context"
	"log"
	"strings"

	registry "gitea.loveuer.com/loveuer/cluster/pkg/model/registry"
	"gitea.loveuer.com/loveuer/cluster/pkg/resp"
	"gitea.loveuer.com/loveuer/cluster/pkg/store"
	"github.com/gofiber/fiber/v3"
	"gorm.io/gorm"
)

func Registry(ctx context.Context, db *gorm.DB, store store.Store) fiber.Handler {
	if err := db.AutoMigrate(
		&registry.Repository{},
		&registry.Blob{},
		&registry.Manifest{},
		&registry.Tag{},
		&registry.BlobUpload{},
		&registry.RegistryConfig{},
	); err != nil {
		log.Fatalf("failed to migrate database: %v", err)
	}

	if err := store.CreatePartition(ctx, "registry"); err != nil {
		log.Fatalf("failed to create registry partition: %v", err)
	}

	return func(c fiber.Ctx) error {
		if isBlob(c) {
			return HandleBlobs(c, db, store)
		}

		if isManifest(c) {
			return HandleManifest(c, db, store)
		}

		if isTags(c) {
			return HandleTags(c, db, store)
		}

		if isCatalog(c) {
			return HandleCatalog(c, db, store)
		}

		if isReferrers(c) {
			return HandleReferrers(c, db, store)
		}

		// Handle root v2 endpoint
		if c.Path() == "/v2/" {
			c.Set("Docker-Distribution-API-Version", "registry/2.0")
			return c.SendStatus(200)
		}

		c.Set("Docker-Distribution-API-Version", "registry/2.0")

		log.Printf("[Warn] Registry: unknown endpoint - path = %s, method = %s, headers = %v", c.Path(), c.Method(), &c.Request().Header)

		return resp.R404(c, "UNKNOWN_ENDPOINT", nil, "endpoint not found")
	}
}

func isBlob(c fiber.Ctx) bool {
	elem := strings.Split(c.Path(), "/")
	elem = elem[1:]
	if elem[len(elem)-1] == "" {
		elem = elem[:len(elem)-1]
	}
	if len(elem) < 3 {
		return false
	}
	return elem[len(elem)-2] == "blobs" || (elem[len(elem)-3] == "blobs" &&
		elem[len(elem)-2] == "uploads")
}

func isManifest(c fiber.Ctx) bool {
	elems := strings.Split(c.Path(), "/")
	elems = elems[1:]
	if len(elems) < 4 {
		return false
	}
	return elems[len(elems)-2] == "manifests"
}

func isTags(c fiber.Ctx) bool {
	elems := strings.Split(c.Path(), "/")
	elems = elems[1:]
	if len(elems) < 4 {
		return false
	}
	return elems[len(elems)-2] == "tags"
}

func isCatalog(c fiber.Ctx) bool {
	elems := strings.Split(c.Path(), "/")
	elems = elems[1:]
	if len(elems) < 2 {
		return false
	}

	return elems[len(elems)-1] == "_catalog"
}

func isReferrers(c fiber.Ctx) bool {
	elems := strings.Split(c.Path(), "/")
	elems = elems[1:]
	if len(elems) < 4 {
		return false
	}

	return elems[len(elems)-2] == "referrers"
}