package registry

import (
	"encoding/json"
	"fmt"
	"github.com/dotcloud/docker/auth"
	"github.com/dotcloud/docker/utils"
	"github.com/shin-/cookiejar"
	"io"
	"io/ioutil"
	"net/http"
	"net/url"
	"strings"
)

func doWithCookies(c *http.Client, req *http.Request) (*http.Response, error) {
	for _, cookie := range c.Jar.Cookies(req.URL) {
		req.AddCookie(cookie)
	}
	return c.Do(req)
}

// Retrieve the history of a given image from the Registry.
// Return a list of the parent's json (requested image included)
func (r *Registry) GetRemoteHistory(imgId, registry string, token []string) ([]string, error) {
	client := r.getHttpClient()

	req, err := http.NewRequest("GET", registry+"/images/"+imgId+"/ancestry", nil)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
	res, err := client.Do(req)
	if err != nil || res.StatusCode != 200 {
		if res != nil {
			return nil, fmt.Errorf("Internal server error: %d trying to fetch remote history for %s", res.StatusCode, imgId)
		}
		return nil, err
	}
	defer res.Body.Close()

	jsonString, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, fmt.Errorf("Error while reading the http response: %s\n", err)
	}

	utils.Debugf("Ancestry: %s", jsonString)
	history := new([]string)
	if err := json.Unmarshal(jsonString, history); err != nil {
		return nil, err
	}
	return *history, nil
}

func (r *Registry) getHttpClient() *http.Client {
	if r.httpClient == nil {
		r.httpClient = &http.Client{}
		r.httpClient.Jar = cookiejar.NewCookieJar()
	}
	return r.httpClient
}

// Check if an image exists in the Registry
func (r *Registry) LookupRemoteImage(imgId, registry string, authConfig *auth.AuthConfig) bool {
	rt := &http.Transport{Proxy: http.ProxyFromEnvironment}

	req, err := http.NewRequest("GET", registry+"/images/"+imgId+"/json", nil)
	if err != nil {
		return false
	}
	req.SetBasicAuth(authConfig.Username, authConfig.Password)
	res, err := rt.RoundTrip(req)
	return err == nil && res.StatusCode == 307
}

func (r *Registry) getImagesInRepository(repository string, authConfig *auth.AuthConfig) ([]map[string]string, error) {
	u := auth.IndexServerAddress() + "/repositories/" + repository + "/images"
	req, err := http.NewRequest("GET", u, nil)
	if err != nil {
		return nil, err
	}
	if authConfig != nil && len(authConfig.Username) > 0 {
		req.SetBasicAuth(authConfig.Username, authConfig.Password)
	}
	res, err := r.getHttpClient().Do(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	// Repository doesn't exist yet
	if res.StatusCode == 404 {
		return nil, nil
	}

	jsonData, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, err
	}

	imageList := []map[string]string{}

	err = json.Unmarshal(jsonData, &imageList)
	if err != nil {
		utils.Debugf("Body: %s (%s)\n", res.Body, u)
		return nil, err
	}

	return imageList, nil
}

// Retrieve an image from the Registry.
// Returns the Image object as well as the layer as an Archive (io.Reader)
func (r *Registry) GetRemoteImageJson(stdout io.Writer, imgId, registry string, token []string) ([]byte, error) {
	client := r.getHttpClient()

	fmt.Fprintf(stdout, "Pulling %s metadata\r\n", imgId)
	// Get the Json
	req, err := http.NewRequest("GET", registry+"/images/"+imgId+"/json", nil)
	if err != nil {
		return nil, fmt.Errorf("Failed to download json: %s", err)
	}
	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
	res, err := client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("Failed to download json: %s", err)
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		return nil, fmt.Errorf("HTTP code %d", res.StatusCode)
	}
	jsonString, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, fmt.Errorf("Failed to parse downloaded json: %s (%s)", err, jsonString)
	}
	return jsonString, nil
}

func (r *Registry) GetRemoteImageLayer(stdout io.Writer, imgId, registry string, token []string) (io.Reader, error) {
	client := r.getHttpClient()

	req, err := http.NewRequest("GET", registry+"/images/"+imgId+"/layer", nil)
	if err != nil {
		return nil, fmt.Errorf("Error while getting from the server: %s\n", err)
	}
	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
	res, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	return utils.ProgressReader(res.Body, int(res.ContentLength), stdout, "Downloading %v/%v (%v)"), nil
}

func (r *Registry) GetRemoteTags(stdout io.Writer, registries []string, repository string, token []string) (map[string]string, error) {
	client := r.getHttpClient()
	if strings.Count(repository, "/") == 0 {
		// This will be removed once the Registry supports auto-resolution on
		// the "library" namespace
		repository = "library/" + repository
	}
	for _, host := range registries {
		endpoint := fmt.Sprintf("https://%s/v1/repositories/%s/tags", host, repository)
		req, err := http.NewRequest("GET", endpoint, nil)
		if err != nil {
			return nil, err
		}
		req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
		res, err := client.Do(req)
		defer res.Body.Close()
		utils.Debugf("Got status code %d from %s", res.StatusCode, endpoint)
		if err != nil || (res.StatusCode != 200 && res.StatusCode != 404) {
			continue
		} else if res.StatusCode == 404 {
			return nil, fmt.Errorf("Repository not found")
		}

		result := make(map[string]string)

		rawJson, err := ioutil.ReadAll(res.Body)
		if err != nil {
			return nil, err
		}
		if err := json.Unmarshal(rawJson, &result); err != nil {
			return nil, err
		}
		return result, nil
	}
	return nil, fmt.Errorf("Could not reach any registry endpoint")
}

func (r *Registry) getImageForTag(stdout io.Writer, tag, remote, registry string, token []string) (string, error) {
	client := r.getHttpClient()

	if !strings.Contains(remote, "/") {
		remote = "library/" + remote
	}

	registryEndpoint := "https://" + registry + "/v1"
	repositoryTarget := registryEndpoint + "/repositories/" + remote + "/tags/" + tag

	req, err := http.NewRequest("GET", repositoryTarget, nil)
	if err != nil {
		return "", err
	}
	req.Header.Set("Authorization", "Token "+strings.Join(token, ", "))
	res, err := client.Do(req)
	if err != nil {
		return "", fmt.Errorf("Error while retrieving repository info: %v", err)
	}
	defer res.Body.Close()
	if res.StatusCode == 403 {
		return "", fmt.Errorf("You aren't authorized to access this resource")
	} else if res.StatusCode != 200 {
		return "", fmt.Errorf("HTTP code: %d", res.StatusCode)
	}

	var imgId string
	rawJson, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return "", err
	}
	if err = json.Unmarshal(rawJson, &imgId); err != nil {
		return "", err
	}
	return imgId, nil
}

func (r *Registry) GetRepositoryData(remote string) (*RepositoryData, error) {
	client := r.getHttpClient()

	utils.Debugf("Pulling repository %s from %s\r\n", remote, auth.IndexServerAddress())
	repositoryTarget := auth.IndexServerAddress() + "/repositories/" + remote + "/images"

	req, err := http.NewRequest("GET", repositoryTarget, nil)
	if err != nil {
		return nil, err
	}
	if r.authConfig != nil && len(r.authConfig.Username) > 0 {
		req.SetBasicAuth(r.authConfig.Username, r.authConfig.Password)
	}
	req.Header.Set("X-Docker-Token", "true")

	res, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode == 401 {
		return nil, fmt.Errorf("Please login first (HTTP code %d)", res.StatusCode)
	}
	// TODO: Right now we're ignoring checksums in the response body.
	// In the future, we need to use them to check image validity.
	if res.StatusCode != 200 {
		return nil, fmt.Errorf("HTTP code: %d", res.StatusCode)
	}

	var tokens []string
	if res.Header.Get("X-Docker-Token") != "" {
		tokens = res.Header["X-Docker-Token"]
	}

	var endpoints []string
	if res.Header.Get("X-Docker-Endpoints") != "" {
		endpoints = res.Header["X-Docker-Endpoints"]
	} else {
		return nil, fmt.Errorf("Index response didn't contain any endpoints")
	}

	checksumsJson, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, err
	}
	remoteChecksums := []*ImgData{}
	if err := json.Unmarshal(checksumsJson, &remoteChecksums); err != nil {
		return nil, err
	}

	// Forge a better object from the retrieved data
	imgsData := make(map[string]*ImgData)
	for _, elem := range remoteChecksums {
		imgsData[elem.Id] = elem
	}

	return &RepositoryData{
		ImgList:   imgsData,
		Endpoints: endpoints,
		Tokens:    tokens,
	}, nil
}

// // Push a local image to the registry
// func (r *Registry) PushImage(stdout io.Writer, img *Image, registry string, token []string) error {
// 	registry = "https://" + registry + "/v1"

// 	client := graph.getHttpClient()
// 	jsonRaw, err := ioutil.ReadFile(path.Join(graph.Root, img.Id, "json"))
// 	if err != nil {
// 		return fmt.Errorf("Error while retreiving the path for {%s}: %s", img.Id, err)
// 	}

// 	fmt.Fprintf(stdout, "Pushing %s metadata\r\n", img.Id)

// 	// FIXME: try json with UTF8
// 	jsonData := strings.NewReader(string(jsonRaw))
// 	req, err := http.NewRequest("PUT", registry+"/images/"+img.Id+"/json", jsonData)
// 	if err != nil {
// 		return err
// 	}
// 	req.Header.Add("Content-type", "application/json")
// 	req.Header.Set("Authorization", "Token "+strings.Join(token, ","))

// 	checksum, err := img.Checksum()
// 	if err != nil {
// 		return fmt.Errorf("Error while retrieving checksum for %s: %v", img.Id, err)
// 	}
// 	req.Header.Set("X-Docker-Checksum", checksum)
// 	utils.Debugf("Setting checksum for %s: %s", img.ShortId(), checksum)
// 	res, err := doWithCookies(client, req)
// 	if err != nil {
// 		return fmt.Errorf("Failed to upload metadata: %s", err)
// 	}
// 	defer res.Body.Close()
// 	if len(res.Cookies()) > 0 {
// 		client.Jar.SetCookies(req.URL, res.Cookies())
// 	}
// 	if res.StatusCode != 200 {
// 		errBody, err := ioutil.ReadAll(res.Body)
// 		if err != nil {
// 			return fmt.Errorf("HTTP code %d while uploading metadata and error when"+
// 				" trying to parse response body: %v", res.StatusCode, err)
// 		}
// 		var jsonBody map[string]string
// 		if err := json.Unmarshal(errBody, &jsonBody); err != nil {
// 			errBody = []byte(err.Error())
// 		} else if jsonBody["error"] == "Image already exists" {
// 			fmt.Fprintf(stdout, "Image %v already uploaded ; skipping\n", img.Id)
// 			return nil
// 		}
// 		return fmt.Errorf("HTTP code %d while uploading metadata: %s", res.StatusCode, errBody)
// 	}

// 	fmt.Fprintf(stdout, "Pushing %s fs layer\r\n", img.Id)
// 	root, err := img.root()
// 	if err != nil {
// 		return err
// 	}

// 	var layerData *TempArchive
// 	// If the archive exists, use it
// 	file, err := os.Open(layerArchivePath(root))
// 	if err != nil {
// 		if os.IsNotExist(err) {
// 			// If the archive does not exist, create one from the layer
// 			layerData, err = graph.TempLayerArchive(img.Id, Xz, stdout)
// 			if err != nil {
// 				return fmt.Errorf("Failed to generate layer archive: %s", err)
// 			}
// 		} else {
// 			return err
// 		}
// 	} else {
// 		defer file.Close()
// 		st, err := file.Stat()
// 		if err != nil {
// 			return err
// 		}
// 		layerData = &TempArchive{file, st.Size()}
// 	}

// 	req3, err := http.NewRequest("PUT", registry+"/images/"+img.Id+"/layer", utils.ProgressReader(layerData, int(layerData.Size), stdout, ""))
// 	if err != nil {
// 		return err
// 	}

// 	req3.ContentLength = -1
// 	req3.TransferEncoding = []string{"chunked"}
// 	req3.Header.Set("Authorization", "Token "+strings.Join(token, ","))
// 	res3, err := doWithCookies(client, req3)
// 	if err != nil {
// 		return fmt.Errorf("Failed to upload layer: %s", err)
// 	}
// 	defer res3.Body.Close()

// 	if res3.StatusCode != 200 {
// 		errBody, err := ioutil.ReadAll(res3.Body)
// 		if err != nil {
// 			return fmt.Errorf("HTTP code %d while uploading metadata and error when"+
// 				" trying to parse response body: %v", res.StatusCode, err)
// 		}
// 		return fmt.Errorf("Received HTTP code %d while uploading layer: %s", res3.StatusCode, errBody)
// 	}
// 	return nil
// }

// // push a tag on the registry.
// // Remote has the format '<user>/<repo>
// func (r *Registry) pushTag(remote, revision, tag, registry string, token []string) error {
// 	// "jsonify" the string
// 	revision = "\"" + revision + "\""
// 	registry = "https://" + registry + "/v1"

// 	utils.Debugf("Pushing tags for rev [%s] on {%s}\n", revision, registry+"/users/"+remote+"/"+tag)

// 	client := graph.getHttpClient()
// 	req, err := http.NewRequest("PUT", registry+"/repositories/"+remote+"/tags/"+tag, strings.NewReader(revision))
// 	if err != nil {
// 		return err
// 	}
// 	req.Header.Add("Content-type", "application/json")
// 	req.Header.Set("Authorization", "Token "+strings.Join(token, ","))
// 	req.ContentLength = int64(len(revision))
// 	res, err := doWithCookies(client, req)
// 	if err != nil {
// 		return err
// 	}
// 	res.Body.Close()
// 	if res.StatusCode != 200 && res.StatusCode != 201 {
// 		return fmt.Errorf("Internal server error: %d trying to push tag %s on %s", res.StatusCode, tag, remote)
// 	}
// 	return nil
// }

// // FIXME: this should really be PushTag
// func (r *Registry) pushPrimitive(stdout io.Writer, remote, tag, imgId, registry string, token []string) error {
// 	// Check if the local impage exists
// 	img, err := graph.Get(imgId)
// 	if err != nil {
// 		fmt.Fprintf(stdout, "Skipping tag %s:%s: %s does not exist\r\n", remote, tag, imgId)
// 		return nil
// 	}
// 	fmt.Fprintf(stdout, "Pushing image %s:%s\r\n", remote, tag)
// 	// Push the image
// 	if err = graph.PushImage(stdout, img, registry, token); err != nil {
// 		return err
// 	}
// 	fmt.Fprintf(stdout, "Registering tag %s:%s\r\n", remote, tag)
// 	// And then the tag
// 	if err = graph.pushTag(remote, imgId, tag, registry, token); err != nil {
// 		return err
// 	}
// 	return nil
// }

// // Retrieve the checksum of an image
// // Priority:
// // - Check on the stored checksums
// // - Check if the archive exists, if it does not, ask the registry
// // - If the archive does exists, process the checksum from it
// // - If the archive does not exists and not found on registry, process checksum from layer
// func (r *Registry) getChecksum(imageId string) (string, error) {
// 	// FIXME: Use in-memory map instead of reading the file each time
// 	if sums, err := graph.getStoredChecksums(); err != nil {
// 		return "", err
// 	} else if checksum, exists := sums[imageId]; exists {
// 		return checksum, nil
// 	}

// 	img, err := graph.Get(imageId)
// 	if err != nil {
// 		return "", err
// 	}

// 	if _, err := os.Stat(layerArchivePath(graph.imageRoot(imageId))); err != nil {
// 		if os.IsNotExist(err) {
// 			// TODO: Ask the registry for the checksum
// 			//       As the archive is not there, it is supposed to come from a pull.
// 		} else {
// 			return "", err
// 		}
// 	}

// 	checksum, err := img.Checksum()
// 	if err != nil {
// 		return "", err
// 	}
// 	return checksum, nil
// }

// // Push a repository to the registry.
// // Remote has the format '<user>/<repo>
// func (r *Registry) PushRepository(stdout io.Writer, remote string, localRepo Repository, authConfig *auth.AuthConfig) error {
// 	client := graph.getHttpClient()
// 	// FIXME: Do not reset the cookie each time? (need to reset it in case updating latest of a repo and repushing)
// 	client.Jar = cookiejar.NewCookieJar()
// 	var imgList []*ImgListJson

// 	fmt.Fprintf(stdout, "Processing checksums\n")
// 	imageSet := make(map[string]struct{})

// 	for tag, id := range localRepo {
// 		img, err := graph.Get(id)
// 		if err != nil {
// 			return err
// 		}
// 		img.WalkHistory(func(img *Image) error {
// 			if _, exists := imageSet[img.Id]; exists {
// 				return nil
// 			}
// 			imageSet[img.Id] = struct{}{}
// 			checksum, err := graph.getChecksum(img.Id)
// 			if err != nil {
// 				return err
// 			}
// 			imgList = append([]*ImgListJson{{
// 				Id:       img.Id,
// 				Checksum: checksum,
// 				tag:      tag,
// 			}}, imgList...)
// 			return nil
// 		})
// 	}

// 	imgListJson, err := json.Marshal(imgList)
// 	if err != nil {
// 		return err
// 	}

// 	utils.Debugf("json sent: %s\n", imgListJson)

// 	fmt.Fprintf(stdout, "Sending image list\n")
// 	req, err := http.NewRequest("PUT", auth.IndexServerAddress()+"/repositories/"+remote+"/", bytes.NewReader(imgListJson))
// 	if err != nil {
// 		return err
// 	}
// 	req.SetBasicAuth(authConfig.Username, authConfig.Password)
// 	req.ContentLength = int64(len(imgListJson))
// 	req.Header.Set("X-Docker-Token", "true")

// 	res, err := client.Do(req)
// 	if err != nil {
// 		return err
// 	}
// 	defer res.Body.Close()

// 	for res.StatusCode >= 300 && res.StatusCode < 400 {
// 		utils.Debugf("Redirected to %s\n", res.Header.Get("Location"))
// 		req, err = http.NewRequest("PUT", res.Header.Get("Location"), bytes.NewReader(imgListJson))
// 		if err != nil {
// 			return err
// 		}
// 		req.SetBasicAuth(authConfig.Username, authConfig.Password)
// 		req.ContentLength = int64(len(imgListJson))
// 		req.Header.Set("X-Docker-Token", "true")

// 		res, err = client.Do(req)
// 		if err != nil {
// 			return err
// 		}
// 		defer res.Body.Close()
// 	}

// 	if res.StatusCode != 200 && res.StatusCode != 201 {
// 		errBody, err := ioutil.ReadAll(res.Body)
// 		if err != nil {
// 			return err
// 		}
// 		return fmt.Errorf("Error: Status %d trying to push repository %s: %s", res.StatusCode, remote, errBody)
// 	}

// 	var token, endpoints []string
// 	if res.Header.Get("X-Docker-Token") != "" {
// 		token = res.Header["X-Docker-Token"]
// 		utils.Debugf("Auth token: %v", token)
// 	} else {
// 		return fmt.Errorf("Index response didn't contain an access token")
// 	}
// 	if res.Header.Get("X-Docker-Endpoints") != "" {
// 		endpoints = res.Header["X-Docker-Endpoints"]
// 	} else {
// 		return fmt.Errorf("Index response didn't contain any endpoints")
// 	}

// 	// FIXME: Send only needed images
// 	for _, registry := range endpoints {
// 		fmt.Fprintf(stdout, "Pushing repository %s to %s (%d tags)\r\n", remote, registry, len(localRepo))
// 		// For each image within the repo, push them
// 		for _, elem := range imgList {
// 			if err := graph.pushPrimitive(stdout, remote, elem.tag, elem.Id, registry, token); err != nil {
// 				// FIXME: Continue on error?
// 				return err
// 			}
// 		}
// 	}

// 	req2, err := http.NewRequest("PUT", auth.IndexServerAddress()+"/repositories/"+remote+"/images", bytes.NewReader(imgListJson))
// 	if err != nil {
// 		return err
// 	}
// 	req2.SetBasicAuth(authConfig.Username, authConfig.Password)
// 	req2.Header["X-Docker-Endpoints"] = endpoints
// 	req2.ContentLength = int64(len(imgListJson))
// 	res2, err := client.Do(req2)
// 	if err != nil {
// 		return err
// 	}
// 	defer res2.Body.Close()
// 	if res2.StatusCode != 204 {
// 		if errBody, err := ioutil.ReadAll(res2.Body); err != nil {
// 			return err
// 		} else {
// 			return fmt.Errorf("Error: Status %d trying to push checksums %s: %s", res2.StatusCode, remote, errBody)
// 		}
// 	}

// 	return nil
// }

func (r *Registry) SearchRepositories(stdout io.Writer, term string) (*SearchResults, error) {
	client := r.getHttpClient()
	u := auth.IndexServerAddress() + "/search?q=" + url.QueryEscape(term)
	req, err := http.NewRequest("GET", u, nil)
	if err != nil {
		return nil, err
	}
	res, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		return nil, fmt.Errorf("Unexepected status code %d", res.StatusCode)
	}
	rawData, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, err
	}
	result := new(SearchResults)
	err = json.Unmarshal(rawData, result)
	return result, err
}

type SearchResults struct {
	Query      string              `json:"query"`
	NumResults int                 `json:"num_results"`
	Results    []map[string]string `json:"results"`
}

type RepositoryData struct {
	ImgList   map[string]*ImgData
	Endpoints []string
	Tokens    []string
}

type ImgData struct {
	Id       string `json:"id"`
	Checksum string `json:"checksum,omitempty"`
	Tag      string `json:",omitempty"`
}

type Registry struct {
	httpClient *http.Client
	authConfig *auth.AuthConfig
}

func NewRegistry(authConfig *auth.AuthConfig) *Registry {
	return &Registry{
		authConfig: authConfig,
	}
}