package service

import (
	"context"
	"crypto/tls"
	"fmt"
	"net"
	"net/http"
	"time"

	"mstore/app/handler"
	"mstore/app/logger"
	"mstore/app/router"
)

const protocol = "tcp"

type ServiceParams struct {
	Handler  *handler.Handler
	X509Cert string
	X509Key  string
	Portnum  int64
	Address  string
}

type Service struct {
	hand *handler.Handler
	rout *router.Router
	logg *logger.Logger

	address  string
	portnum  int64
	x509cert []byte
	x509key  []byte

	listen net.Listener
	hsrv   *http.Server
}

func NewService(params *ServiceParams) (*Service, error) {
	var err error
	svc := &Service{
		hand:     params.Handler,
		x509cert: []byte(params.X509Cert),
		x509key:  []byte(params.X509Key),
		portnum:  params.Portnum,
		address:  params.Address,
	}
	svc.logg = logger.NewLogger("service")
	return svc, err
}

func (svc *Service) Build() error {
	var err error
	svc.logg.Infof("Service build ")

	svc.rout = router.NewRouter()

	svc.rout.Use(router.NewRecoveryMiddleware(svc.logg.Errorf))
	svc.rout.Use(router.NewLoggingMiddleware(svc.logg.Infof))
	svc.rout.Use(router.NewCorsMiddleware())

	svc.rout.Get("/v3/api/service/hello", svc.hand.SendHello)

	svc.rout.Head("/v3/api/file/{filepath}", svc.hand.FileExists)
	svc.rout.Put("/v3/api/file/{filepath}", svc.hand.PutFile)
	svc.rout.Get("/v3/api/file/{filepath}", svc.hand.GetFile)
	svc.rout.Delete("/v3/api/file/{filepath}", svc.hand.DeleteFile)
	svc.rout.Get("/v3/api/files/{filepath}", svc.hand.ListFiles)
	svc.rout.Get("/v2/", svc.hand.GetVersion)

	// https://github.com/opencontainers/distribution-spec/blob/main/spec.md
	//
	// Pulling manifests
	//
	// To pull a manifest, perform a GET request to a URL in the following form:
	// /v2/<name>/manifests/<reference> end-3
	//
	// <name> refers to the namespace of the repository.
	// <reference> MUST be either (a) the digest of the manifest or (b) a tag.
	// The <reference> MUST NOT be in any other format.
	//
	// Throughout this document, <name> MUST match the following regular expression:
	//
	// [a-z0-9]+((\.|_|__|-+)[a-z0-9]+)*(\/[a-z0-9]+((\.|_|__|-+)[a-z0-9]+)*)*
	//
	// Throughout this document, <reference> as a tag MUST be at most 128 characters
	// in length and MUST match the following regular expression:
	//
	// [a-zA-Z0-9_][a-zA-Z0-9._-]{0,127}

	// Pushing Manifests
	//
	// To push a manifest, perform a PUT request to a path in the following format,
	// and with the following headers and body: /v2/<name>/manifests/<reference>

	const reference = `{reference:[a-zA-Z0-9_][a-zA-Z0-9._-]{0,127}}`
	svc.rout.Head(`/v2/{name}/manifests/{reference}`, svc.hand.ManifestExists)

	svc.rout.Put(`/v2/{name}/manifests/{reference}`, svc.hand.PutManifest)

	// Pulling blobs
	//
	// To pull a blob, perform a GET request to a URL in the following form:
	// /v2/<name>/blobs/<digest>
	//
	// <name> is the namespace of the repository, and <digest> is the blob's digest.
	//
	// A GET request to an existing blob URL MUST provide the expected blob,
	// with a response code that MUST be 200 OK. A successful response SHOULD contain
	// the digest of the uploaded blob in the header Docker-Content-Digest. //
	// If present, the value of this header MUST be a digest matching that of the
	// response body. Most clients MAY ignore the value, but if it is used,
	// the client MUST verify the value matches the returned response body.
	// Clients SHOULD verify that the response body matches the requested digest.
	//
	// If the blob is not found in the repository, the response code MUST be 404 Not Found.

	svc.rout.Head(`/v2/{name}/blobs/{digest}`, svc.hand.BlobExists)

	// Single POST
	//
	// Registries MAY support pushing blobs using a single POST request.
	//
	// To push a blob monolithically by using a single POST request, perform a POST request
	// to a URL in the following form, and with the following headers and body:
	//
	// /v2/<name>/blobs/uploads/?digest=<digest>
	//
	// Content-Length: <length>
	// Content-Type: application/octet-stream
	//
	// <upload byte stream>
	//
	// Here, <name> is the repository's namespace, <digest> is the blob's digest,
	// and <length> is the size (in bytes) of the blob.
	//
	// The Content-Length header MUST match the blob's actual content length.
	// Likewise, the <digest> MUST match the blob's digest.
	//
	// Registries that do not support single request monolithic uploads SHOULD
	// return a 202 Accepted status code and Location header and clients SHOULD
	// proceed with a subsequent PUT request, as described by the POST then PUT upload method.
	//
	// Successful completion of the request MUST return a 201 Created and MUST include the following header:
	//
	// Location: <blob-location>
	//
	// Here, <blob-location> is a pullable blob URL. This location does not necessarily
	// have to be served by your registry, for example, in the case of a signed URL from
	// some cloud storage provider that your registry generates.

	svc.rout.Post(`/v2/{name}/blobs/uploads/`, svc.hand.PostUpload)

	// Pushing a blob in chunks
	//
	// A chunked blob upload is accomplished in three phases:
	//
	// - Obtain a session ID (upload URL) (POST)
	// - Upload the chunks (PATCH)
	// - Close the session (PUT)
	//
	// For information on obtaining a session ID, reference the above section on pushing
	// a blob monolithically via the POST/PUT method. The process remains unchanged for
	// chunked upload, except that the post request MUST include the following header:
	//
	// Content-Length: 0
	//
	// If the registry has a minimum chunk size, the POST response SHOULD include
	// the following header, where <size> is the size in bytes
	// (see the blob PATCH definition for usage):
	//
	// OCI-Chunk-Min-Length: <size>
	//
	// Please reference the above section for restrictions on the <location>.
	//
	// To upload a chunk, issue a PATCH request to a URL path in the following format,
	// and with the following headers and body:
	//
	// URL path: <location>
	//
	// Content-Type: application/octet-stream
	// Content-Range: <range>
	// Content-Length: <length>
	//
	// <upload byte stream of chunk>
	//
	// The <location> refers to the URL obtained from the preceding POST request.

	svc.rout.Patch(`/v2/{name}/blobs/uploads/{reference}`, svc.hand.PatchUpload)

	// To close the session, issue a PUT request to a url in the following format,
	// and with the following headers (and optional body, depending on whether or not
	// the final chunk was uploaded already via a PATCH request):
	//
	// <location>?digest=<digest>
	//
	// Content-Length: <length of chunk, if present>
	// Content-Range: <range of chunk, if present>
	// Content-Type: application/octet-stream <if chunk provided>
	//
	// OPTIONAL: <final chunk byte stream>
	//
	// The closing PUT request MUST include the <digest> of the whole blob
	// (not the final chunk) as a query parameter.
	//
	// The response to a successful closing of the session MUST be 201 Created,
	// and MUST contain the following header:
	//
	// Location: <blob-location>
	//
	// Here, <blob-location> is a pullable blob URL.

	svc.rout.Put(`/v2/{name}/uploads/{reference}`, svc.hand.PutUpload)

	// Pulling blobs
	//
	// To pull a blob, perform a GET request to a URL in the following form:
	//
	// /v2/<name>/blobs/<digest> end-2
	//
	// <name> is the namespace of the repository, and <digest> is the blob's digest.
	//
	// A GET request to an existing blob URL MUST provide the expected blob,
	// with a response code that MUST be 200 OK.
	// A successful response SHOULD contain the digest of the uploaded blob in the header Docker-Content-Digest.
	// If present, the value of this header MUST be a digest matching that of the response body.
	// Most clients MAY ignore the value, but if it is used, the client MUST verify the value
	// matches the returned response body. Clients SHOULD verify that the response body
	// matches the requested digest.
	//
	// If the blob is not found in the repository, the response code MUST be 404 Not Found.
	//
	// A registry SHOULD support the Range request header in accordance with RFC 9110.

	svc.rout.Get(`/v2/{name}/blobs/{digest}`, svc.hand.GetBlob)

	// Deleting Blobs
	//
	// To delete a blob, perform a DELETE request to a path in the following format:
	//
	// /v2/<name>/blobs/<digest>
	//
	// <name> is the namespace of the repository, and <digest> is the digest
	// of the blob to be deleted.
	//
	// Upon success, the registry MUST respond with code 202 Accepted.
	// If the blob is not found, a 404 Not Found code MUST be returned.
	// If blob deletion is disabled, the registry MUST respond with either
	// a 400 Bad Request or a 405 Method Not Allowed.

	svc.rout.Delete(`/v2/{name}/blobs/{digest}`, svc.hand.DeleteBlob)

	svc.rout.NotFound(svc.hand.NotFound)

	selector := svc.rout.Selector()
	for _, item := range selector.Routes {
		svc.logg.Infof("%s\t%s", item.Method, item.RawPath)
	}

	const useTLS = true
	if useTLS {
		tlsCert, err := tls.X509KeyPair(svc.x509cert, svc.x509key)

		if err != nil {
			return err
		}

		tlsConfig := tls.Config{
			Certificates:       []tls.Certificate{tlsCert},
			ClientAuth:         tls.NoClientCert,
			InsecureSkipVerify: true,
		}

		listenAddress := fmt.Sprintf("%s:%d", svc.address, svc.portnum)
		svc.listen, err = tls.Listen(protocol, listenAddress, &tlsConfig)
		if err != nil {
			return err
		}

	} else {
		listenAddress := fmt.Sprintf("%s:%d", svc.address, svc.portnum)
		svc.listen, err = net.Listen(protocol, listenAddress)
		if err != nil {
			return err
		}
	}
	svc.logg.Infof("Service listening at %v", svc.listen.Addr())
	svc.hsrv = &http.Server{
		Handler: svc.rout,
	}
	return err
}

func (svc *Service) Run() error {
	var err error
	svc.logg.Infof("Service run")
	err = svc.hsrv.Serve(svc.listen)
	if err == http.ErrServerClosed {
		svc.logg.Warningf("Service Closed")
		err = nil
	}
	if err != nil {
		return err
	}
	return err
}

func (svc *Service) Stop() {
	if svc.hsrv != nil {
		svc.logg.Infof("Service stop")
		downWaiting := 10 * time.Second
		ctx, cancel := context.WithTimeout(context.Background(), downWaiting)
		defer cancel()
		err := svc.hsrv.Shutdown(ctx)
		if err != nil {
			svc.logg.Errorf("Error service shutdown: %v", err)
		}
	}
}