package cfclient

import (
	"bytes"
	"crypto/tls"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"mime/multipart"
	"net/http"
	"net/url"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/pkg/errors"
)

type AppResponse struct {
	Count     int           `json:"total_results"`
	Pages     int           `json:"total_pages"`
	NextUrl   string        `json:"next_url"`
	Resources []AppResource `json:"resources"`
}

type AppResource struct {
	Meta   Meta `json:"metadata"`
	Entity App  `json:"entity"`
}

type AppState string

const (
	APP_STOPPED AppState = "STOPPED"
	APP_STARTED AppState = "STARTED"
)

type HealthCheckType string

const (
	HEALTH_HTTP    HealthCheckType = "http"
	HEALTH_PORT    HealthCheckType = "port"
	HEALTH_PROCESS HealthCheckType = "process"
)

type DockerCredentials struct {
	Username string `json:"username,omitempty"`
	Password string `json:"password,omitempty"`
}

type AppCreateRequest struct {
	Name      string `json:"name"`
	SpaceGuid string `json:"space_guid"`
	// Memory for the app, in MB
	Memory int `json:"memory,omitempty"`
	// Instances to startup
	Instances int `json:"instances,omitempty"`
	// Disk quota in MB
	DiskQuota int    `json:"disk_quota,omitempty"`
	StackGuid string `json:"stack_guid,omitempty"`
	// Desired state of the app. Either "STOPPED" or "STARTED"
	State AppState `json:"state,omitempty"`
	// Command to start an app
	Command string `json:"command,omitempty"`
	// Buildpack to build the app. Three options:
	// 1. Blank for autodetection
	// 2. GIT url
	// 3. Name of an installed buildpack
	Buildpack string `json:"buildpack,omitempty"`
	// Endpoint to check if an app is healthy
	HealthCheckHttpEndpoint string `json:"health_check_http_endpoint,omitempty"`
	// How to check if an app is healthy. Defaults to HEALTH_PORT if not specified
	HealthCheckType   HealthCheckType        `json:"health_check_type,omitempty"`
	Diego             bool                   `json:"diego,omitempty"`
	EnableSSH         bool                   `json:"enable_ssh,omitempty"`
	DockerImage       string                 `json:"docker_image,omitempty"`
	DockerCredentials DockerCredentials      `json:"docker_credentials,omitempty"`
	Environment       map[string]interface{} `json:"environment_json,omitempty"`
}

type App struct {
	Guid                     string                 `json:"guid"`
	CreatedAt                string                 `json:"created_at"`
	UpdatedAt                string                 `json:"updated_at"`
	Name                     string                 `json:"name"`
	Memory                   int                    `json:"memory"`
	Instances                int                    `json:"instances"`
	DiskQuota                int                    `json:"disk_quota"`
	SpaceGuid                string                 `json:"space_guid"`
	StackGuid                string                 `json:"stack_guid"`
	State                    string                 `json:"state"`
	PackageState             string                 `json:"package_state"`
	Command                  string                 `json:"command"`
	Buildpack                string                 `json:"buildpack"`
	DetectedBuildpack        string                 `json:"detected_buildpack"`
	DetectedBuildpackGuid    string                 `json:"detected_buildpack_guid"`
	HealthCheckHttpEndpoint  string                 `json:"health_check_http_endpoint"`
	HealthCheckType          string                 `json:"health_check_type"`
	HealthCheckTimeout       int                    `json:"health_check_timeout"`
	Diego                    bool                   `json:"diego"`
	EnableSSH                bool                   `json:"enable_ssh"`
	DetectedStartCommand     string                 `json:"detected_start_command"`
	DockerImage              string                 `json:"docker_image"`
	DockerCredentials        map[string]interface{} `json:"docker_credentials_json"`
	Environment              map[string]interface{} `json:"environment_json"`
	StagingFailedReason      string                 `json:"staging_failed_reason"`
	StagingFailedDescription string                 `json:"staging_failed_description"`
	Ports                    []int                  `json:"ports"`
	SpaceURL                 string                 `json:"space_url"`
	SpaceData                SpaceResource          `json:"space"`
	PackageUpdatedAt         string                 `json:"package_updated_at"`
	c                        *Client
}

type AppInstance struct {
	State string    `json:"state"`
	Since sinceTime `json:"since"`
}

type AppStats struct {
	State string `json:"state"`
	Stats struct {
		Name      string   `json:"name"`
		Uris      []string `json:"uris"`
		Host      string   `json:"host"`
		Port      int      `json:"port"`
		Uptime    int      `json:"uptime"`
		MemQuota  int      `json:"mem_quota"`
		DiskQuota int      `json:"disk_quota"`
		FdsQuota  int      `json:"fds_quota"`
		Usage     struct {
			Time statTime `json:"time"`
			CPU  float64  `json:"cpu"`
			Mem  int      `json:"mem"`
			Disk int      `json:"disk"`
		} `json:"usage"`
	} `json:"stats"`
}

type AppSummary struct {
	Guid                     string                 `json:"guid"`
	Name                     string                 `json:"name"`
	ServiceCount             int                    `json:"service_count"`
	RunningInstances         int                    `json:"running_instances"`
	SpaceGuid                string                 `json:"space_guid"`
	StackGuid                string                 `json:"stack_guid"`
	Buildpack                string                 `json:"buildpack"`
	DetectedBuildpack        string                 `json:"detected_buildpack"`
	Environment              map[string]interface{} `json:"environment_json"`
	Memory                   int                    `json:"memory"`
	Instances                int                    `json:"instances"`
	DiskQuota                int                    `json:"disk_quota"`
	State                    string                 `json:"state"`
	Command                  string                 `json:"command"`
	PackageState             string                 `json:"package_state"`
	HealthCheckType          string                 `json:"health_check_type"`
	HealthCheckTimeout       int                    `json:"health_check_timeout"`
	StagingFailedReason      string                 `json:"staging_failed_reason"`
	StagingFailedDescription string                 `json:"staging_failed_description"`
	Diego                    bool                   `json:"diego"`
	DockerImage              string                 `json:"docker_image"`
	DetectedStartCommand     string                 `json:"detected_start_command"`
	EnableSSH                bool                   `json:"enable_ssh"`
	DockerCredentials        map[string]interface{} `json:"docker_credentials_json"`
}

type AppEnv struct {
	// These can have arbitrary JSON so need to map to interface{}
	Environment    map[string]interface{} `json:"environment_json"`
	StagingEnv     map[string]interface{} `json:"staging_env_json"`
	RunningEnv     map[string]interface{} `json:"running_env_json"`
	SystemEnv      map[string]interface{} `json:"system_env_json"`
	ApplicationEnv map[string]interface{} `json:"application_env_json"`
}

// Custom time types to handle non-RFC3339 formatting in API JSON

type sinceTime struct {
	time.Time
}

func (s *sinceTime) UnmarshalJSON(b []byte) (err error) {
	timeFlt, err := strconv.ParseFloat(string(b), 64)
	if err != nil {
		return err
	}
	time := time.Unix(int64(timeFlt), 0)
	*s = sinceTime{time}
	return nil
}

func (s sinceTime) ToTime() time.Time {
	t, _ := time.Parse(time.UnixDate, s.Format(time.UnixDate))
	return t
}

type statTime struct {
	time.Time
}

func (s *statTime) UnmarshalJSON(b []byte) (err error) {
	timeString, err := strconv.Unquote(string(b))
	if err != nil {
		return err
	}

	possibleFormats := [...]string{time.RFC3339, time.RFC3339Nano, "2006-01-02 15:04:05 -0700", "2006-01-02 15:04:05 MST"}

	var value time.Time
	for _, possibleFormat := range possibleFormats {
		if value, err = time.Parse(possibleFormat, timeString); err == nil {
			*s = statTime{value}
			return nil
		}
	}

	return fmt.Errorf("%s was not in any of the expected Date Formats %v", timeString, possibleFormats)
}

func (s statTime) ToTime() time.Time {
	t, _ := time.Parse(time.UnixDate, s.Format(time.UnixDate))
	return t
}

func (a *App) Space() (Space, error) {
	var spaceResource SpaceResource
	r := a.c.NewRequest("GET", a.SpaceURL)
	resp, err := a.c.DoRequest(r)
	if err != nil {
		return Space{}, errors.Wrap(err, "Error requesting space")
	}
	defer resp.Body.Close()
	resBody, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return Space{}, errors.Wrap(err, "Error reading space response")
	}

	err = json.Unmarshal(resBody, &spaceResource)
	if err != nil {
		return Space{}, errors.Wrap(err, "Error unmarshalling body")
	}
	return a.c.mergeSpaceResource(spaceResource), nil
}

func (a *App) Summary() (AppSummary, error) {
	var appSummary AppSummary
	requestUrl := fmt.Sprintf("/v2/apps/%s/summary", a.Guid)
	r := a.c.NewRequest("GET", requestUrl)
	resp, err := a.c.DoRequest(r)
	if err != nil {
		return AppSummary{}, errors.Wrap(err, "Error requesting app summary")
	}
	resBody, err := ioutil.ReadAll(resp.Body)
	defer resp.Body.Close()
	if err != nil {
		return AppSummary{}, errors.Wrap(err, "Error reading app summary body")
	}
	err = json.Unmarshal(resBody, &appSummary)
	if err != nil {
		return AppSummary{}, errors.Wrap(err, "Error unmarshalling app summary")
	}
	return appSummary, nil
}

// ListAppsByQueryWithLimits queries totalPages app info. When totalPages is
// less and equal than 0, it queries all app info
// When there are no more than totalPages apps on server side, all apps info will be returned
func (c *Client) ListAppsByQueryWithLimits(query url.Values, totalPages int) ([]App, error) {
	return c.listApps("/v2/apps?"+query.Encode(), totalPages)
}

func (c *Client) ListAppsByQuery(query url.Values) ([]App, error) {
	return c.listApps("/v2/apps?"+query.Encode(), -1)
}

// GetAppByGuidNoInlineCall will fetch app info including space and orgs information
// Without using inline-relations-depth=2 call
func (c *Client) GetAppByGuidNoInlineCall(guid string) (App, error) {
	var appResource AppResource
	r := c.NewRequest("GET", "/v2/apps/"+guid)
	resp, err := c.DoRequest(r)
	if err != nil {
		return App{}, errors.Wrap(err, "Error requesting apps")
	}
	defer resp.Body.Close()
	resBody, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return App{}, errors.Wrap(err, "Error reading app response body")
	}

	err = json.Unmarshal(resBody, &appResource)
	if err != nil {
		return App{}, errors.Wrap(err, "Error unmarshalling app")
	}
	app := c.mergeAppResource(appResource)

	// If no Space Information no need to check org.
	if app.SpaceGuid != "" {
		//Getting Spaces Resource
		space, err := app.Space()
		if err != nil {
			errors.Wrap(err, "Unable to get the Space for the apps "+app.Name)
		} else {
			app.SpaceData.Entity = space

		}

		//Getting orgResource
		org, err := app.SpaceData.Entity.Org()
		if err != nil {
			errors.Wrap(err, "Unable to get the Org for the apps "+app.Name)
		} else {
			app.SpaceData.Entity.OrgData.Entity = org
		}
	}

	return app, nil
}

func (c *Client) ListApps() ([]App, error) {
	q := url.Values{}
	q.Set("inline-relations-depth", "2")
	return c.ListAppsByQuery(q)
}

func (c *Client) ListAppsByRoute(routeGuid string) ([]App, error) {
	return c.listApps(fmt.Sprintf("/v2/routes/%s/apps", routeGuid), -1)
}

func (c *Client) listApps(requestUrl string, totalPages int) ([]App, error) {
	pages := 0
	apps := []App{}
	for {
		var appResp AppResponse
		r := c.NewRequest("GET", requestUrl)
		resp, err := c.DoRequest(r)

		if err != nil {
			return nil, errors.Wrap(err, "Error requesting apps")
		}
		defer resp.Body.Close()
		resBody, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			return nil, errors.Wrap(err, "Error reading app request")
		}

		err = json.Unmarshal(resBody, &appResp)
		if err != nil {
			return nil, errors.Wrap(err, "Error unmarshalling app")
		}
		for _, app := range appResp.Resources {
			apps = append(apps, c.mergeAppResource(app))
		}

		requestUrl = appResp.NextUrl
		if requestUrl == "" {
			break
		}

		pages += 1
		if totalPages > 0 && pages >= totalPages {
			break
		}
	}
	return apps, nil
}

func (c *Client) GetAppInstances(guid string) (map[string]AppInstance, error) {
	var appInstances map[string]AppInstance

	requestURL := fmt.Sprintf("/v2/apps/%s/instances", guid)
	r := c.NewRequest("GET", requestURL)
	resp, err := c.DoRequest(r)
	if err != nil {
		return nil, errors.Wrap(err, "Error requesting app instances")
	}
	defer resp.Body.Close()
	resBody, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, errors.Wrap(err, "Error reading app instances")
	}
	err = json.Unmarshal(resBody, &appInstances)
	if err != nil {
		return nil, errors.Wrap(err, "Error unmarshalling app instances")
	}
	return appInstances, nil
}

func (c *Client) GetAppEnv(guid string) (AppEnv, error) {
	var appEnv AppEnv

	requestURL := fmt.Sprintf("/v2/apps/%s/env", guid)
	r := c.NewRequest("GET", requestURL)
	resp, err := c.DoRequest(r)
	if err != nil {
		return appEnv, errors.Wrap(err, "Error requesting app env")
	}
	defer resp.Body.Close()
	resBody, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return appEnv, errors.Wrap(err, "Error reading app env")
	}
	err = json.Unmarshal(resBody, &appEnv)
	if err != nil {
		return appEnv, errors.Wrap(err, "Error unmarshalling app env")
	}
	return appEnv, nil
}

func (c *Client) GetAppRoutes(guid string) ([]Route, error) {
	return c.fetchRoutes(fmt.Sprintf("/v2/apps/%s/routes", guid))
}

func (c *Client) GetAppStats(guid string) (map[string]AppStats, error) {
	var appStats map[string]AppStats

	requestURL := fmt.Sprintf("/v2/apps/%s/stats", guid)
	r := c.NewRequest("GET", requestURL)
	resp, err := c.DoRequest(r)
	if err != nil {
		return nil, errors.Wrap(err, "Error requesting app stats")
	}
	defer resp.Body.Close()
	resBody, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, errors.Wrap(err, "Error reading app stats")
	}
	err = json.Unmarshal(resBody, &appStats)
	if err != nil {
		return nil, errors.Wrap(err, "Error unmarshalling app stats")
	}
	return appStats, nil
}

func (c *Client) KillAppInstance(guid string, index string) error {
	requestURL := fmt.Sprintf("/v2/apps/%s/instances/%s", guid, index)
	r := c.NewRequest("DELETE", requestURL)
	resp, err := c.DoRequest(r)
	if err != nil {
		return errors.Wrapf(err, "Error stopping app %s at index %s", guid, index)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 204 {
		return errors.Wrapf(err, "Error stopping app %s at index %s", guid, index)
	}
	return nil
}

func (c *Client) GetAppByGuid(guid string) (App, error) {
	var appResource AppResource
	r := c.NewRequest("GET", "/v2/apps/"+guid+"?inline-relations-depth=2")
	resp, err := c.DoRequest(r)
	if err != nil {
		return App{}, errors.Wrap(err, "Error requesting apps")
	}
	defer resp.Body.Close()
	resBody, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return App{}, errors.Wrap(err, "Error reading app response body")
	}

	err = json.Unmarshal(resBody, &appResource)
	if err != nil {
		return App{}, errors.Wrap(err, "Error unmarshalling app")
	}
	return c.mergeAppResource(appResource), nil
}

func (c *Client) AppByGuid(guid string) (App, error) {
	return c.GetAppByGuid(guid)
}

//AppByName takes an appName, and GUIDs for a space and org, and performs
// the API lookup with those query parameters set to return you the desired
// App object.
func (c *Client) AppByName(appName, spaceGuid, orgGuid string) (app App, err error) {
	query := url.Values{}
	query.Add("q", fmt.Sprintf("organization_guid:%s", orgGuid))
	query.Add("q", fmt.Sprintf("space_guid:%s", spaceGuid))
	query.Add("q", fmt.Sprintf("name:%s", appName))
	apps, err := c.ListAppsByQuery(query)
	if err != nil {
		return
	}
	if len(apps) == 0 {
		err = fmt.Errorf("No app found with name: `%s` in space with GUID `%s` and org with GUID `%s`", appName, spaceGuid, orgGuid)
		return
	}
	app = apps[0]
	return
}

// UploadAppBits uploads the application's contents
func (c *Client) UploadAppBits(file io.Reader, appGUID string) error {
	requestFile, err := ioutil.TempFile("", "requests")

	defer func() {
		requestFile.Close()
		os.Remove(requestFile.Name())
	}()

	writer := multipart.NewWriter(requestFile)
	err = writer.WriteField("resources", "[]")
	if err != nil {
		return errors.Wrapf(err, "Error uploading app %s bits", appGUID)
	}

	part, err := writer.CreateFormFile("application", "application.zip")
	if err != nil {
		return errors.Wrapf(err, "Error uploading app %s bits", appGUID)
	}

	_, err = io.Copy(part, file)
	if err != nil {
		return errors.Wrapf(err, "Error uploading app %s bits, failed to copy all bytes", appGUID)
	}

	err = writer.Close()
	if err != nil {
		return errors.Wrapf(err, "Error uploading app %s bits, failed to close multipart writer", appGUID)
	}

	requestFile.Seek(0, 0)
	fileStats, err := requestFile.Stat()
	if err != nil {
		return errors.Wrapf(err, "Error uploading app %s bits, failed to get temp file stats", appGUID)
	}

	requestURL := fmt.Sprintf("/v2/apps/%s/bits", appGUID)
	r := c.NewRequestWithBody("PUT", requestURL, requestFile)
	req, err := r.toHTTP()
	if err != nil {
		return errors.Wrapf(err, "Error uploading app %s bits", appGUID)
	}

	req.ContentLength = fileStats.Size()
	contentType := fmt.Sprintf("multipart/form-data; boundary=%s", writer.Boundary())
	req.Header.Set("Content-Type", contentType)

	resp, err := c.Do(req)
	if err != nil {
		return errors.Wrapf(err, "Error uploading app %s bits", appGUID)
	}
	if resp.StatusCode != http.StatusCreated {
		return errors.Wrapf(err, "Error uploading app %s bits, response code: %d", appGUID, resp.StatusCode)
	}

	return nil
}

// GetAppBits downloads the application's bits as a tar file
func (c *Client) GetAppBits(guid string) (io.ReadCloser, error) {
	requestURL := fmt.Sprintf("/v2/apps/%s/download", guid)
	req := c.NewRequest("GET", requestURL)
	resp, err := c.DoRequestWithoutRedirects(req)
	if err != nil {
		return nil, errors.Wrapf(err, "Error downloading app %s bits, API request failed", guid)
	}
	if isResponseRedirect(resp) {
		// directly download the bits from blobstore using a non cloud controller transport
		// some blobstores will return a 400 if an Authorization header is sent
		blobStoreLocation := resp.Header.Get("Location")
		tr := &http.Transport{
			TLSClientConfig: &tls.Config{InsecureSkipVerify: c.Config.SkipSslValidation},
		}
		client := &http.Client{Transport: tr}
		resp, err = client.Get(blobStoreLocation)
		if err != nil {
			return nil, errors.Wrapf(err, "Error downloading app %s bits from blobstore", guid)
		}
	} else {
		return nil, errors.Wrapf(err, "Error downloading app %s bits, expected redirect to blobstore", guid)
	}
	return resp.Body, nil
}

// CreateApp creates a new empty application that still needs it's
// app bit uploaded and to be started
func (c *Client) CreateApp(req AppCreateRequest) (App, error) {
	var appResp AppResource
	buf := bytes.NewBuffer(nil)
	err := json.NewEncoder(buf).Encode(req)
	if err != nil {
		return App{}, err
	}
	r := c.NewRequestWithBody("POST", "/v2/apps", buf)
	resp, err := c.DoRequest(r)
	if err != nil {
		return App{}, errors.Wrapf(err, "Error creating app %s", req.Name)
	}
	if resp.StatusCode != http.StatusCreated {
		return App{}, errors.Wrapf(err, "Error creating app %s, response code: %d", req.Name, resp.StatusCode)
	}
	resBody, err := ioutil.ReadAll(resp.Body)
	defer resp.Body.Close()
	if err != nil {
		return App{}, errors.Wrapf(err, "Error reading app %s http response body", req.Name)
	}
	err = json.Unmarshal(resBody, &appResp)
	if err != nil {
		return App{}, errors.Wrapf(err, "Error deserializing app %s response", req.Name)
	}
	return c.mergeAppResource(appResp), nil
}

func (c *Client) StartApp(guid string) error {
	startRequest := strings.NewReader(`{ "state": "STARTED" }`)
	resp, err := c.DoRequest(c.NewRequestWithBody("PUT", fmt.Sprintf("/v2/apps/%s", guid), startRequest))
	if err != nil {
		return err
	}
	if resp.StatusCode != http.StatusNoContent {
		return errors.Wrapf(err, "Error starting app %s, response code: %d", guid, resp.StatusCode)
	}
	return nil
}

func (c *Client) StopApp(guid string) error {
	stopRequest := strings.NewReader(`{ "state": "STOPPED" }`)
	resp, err := c.DoRequest(c.NewRequestWithBody("PUT", fmt.Sprintf("/v2/apps/%s", guid), stopRequest))
	if err != nil {
		return err
	}
	if resp.StatusCode != http.StatusNoContent {
		return errors.Wrapf(err, "Error stopping app %s, response code: %d", guid, resp.StatusCode)
	}
	return nil
}

func (c *Client) DeleteApp(guid string) error {
	resp, err := c.DoRequest(c.NewRequest("DELETE", fmt.Sprintf("/v2/apps/%s", guid)))
	if err != nil {
		return err
	}
	if resp.StatusCode != http.StatusNoContent {
		return errors.Wrapf(err, "Error deleting app %s, response code: %d", guid, resp.StatusCode)
	}
	return nil
}

func (c *Client) mergeAppResource(app AppResource) App {
	app.Entity.Guid = app.Meta.Guid
	app.Entity.CreatedAt = app.Meta.CreatedAt
	app.Entity.UpdatedAt = app.Meta.UpdatedAt
	app.Entity.SpaceData.Entity.Guid = app.Entity.SpaceData.Meta.Guid
	app.Entity.SpaceData.Entity.OrgData.Entity.Guid = app.Entity.SpaceData.Entity.OrgData.Meta.Guid
	app.Entity.c = c
	return app.Entity
}

func isResponseRedirect(res *http.Response) bool {
	switch res.StatusCode {
	case http.StatusTemporaryRedirect, http.StatusPermanentRedirect, http.StatusMovedPermanently, http.StatusFound, http.StatusSeeOther:
		return true
	}
	return false
}