package github

import (
	"encoding/json"
	"fmt"
	"net/http"

	"github.com/pkg/errors"
	"github.com/rancher/norman/httperror"
	"github.com/rancher/norman/types"
	mv3 "github.com/rancher/types/apis/management.cattle.io/v3"
	"github.com/rancher/types/apis/project.cattle.io/v3"

	"github.com/mitchellh/mapstructure"
	"github.com/rancher/norman/api/access"
	"github.com/rancher/norman/types/convert"
	"github.com/rancher/rancher/pkg/pipeline/remote"
	"github.com/rancher/rancher/pkg/pipeline/remote/model"
	"github.com/rancher/rancher/pkg/pipeline/utils"
	"github.com/rancher/rancher/pkg/ref"
	mclient "github.com/rancher/types/client/management/v3"
	"github.com/rancher/types/client/project/v3"
	"github.com/satori/go.uuid"
	"io/ioutil"
	apierror "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"strings"
)

const (
	githubDefaultHostName = "https://github.com"
	actionDisable         = "disable"
	actionTestAndApply    = "testAndApply"
	actionLogin           = "login"
	projectNameField      = "projectName"
)

func (g *GhProvider) Formatter(apiContext *types.APIContext, resource *types.RawResource) {
	if convert.ToBool(resource.Values["enabled"]) {
		resource.AddAction(apiContext, actionDisable)
	}

	resource.AddAction(apiContext, actionTestAndApply)
}

func (g *GhProvider) ActionHandler(actionName string, action *types.Action, request *types.APIContext) error {
	if actionName == actionTestAndApply {
		return g.testAndApply(actionName, action, request)
	} else if actionName == actionDisable {
		return g.disableAction(request)
	}

	return httperror.NewAPIError(httperror.ActionNotAvailable, "")
}

func (g *GhProvider) providerFormatter(apiContext *types.APIContext, resource *types.RawResource) {
	resource.AddAction(apiContext, actionLogin)
}

func (g *GhProvider) providerActionHandler(actionName string, action *types.Action, request *types.APIContext) error {
	if actionName == actionLogin {
		return g.authuser(request)
	}

	return httperror.NewAPIError(httperror.ActionNotAvailable, "")
}

func formGithubRedirectURLFromMap(config map[string]interface{}) string {
	hostname := convert.ToString(config[mclient.GithubConfigFieldHostname])
	clientID := convert.ToString(config[mclient.GithubConfigFieldClientID])
	tls := convert.ToBool(config[mclient.GithubConfigFieldTLS])
	return githubRedirectURL(hostname, clientID, tls)
}

func githubRedirectURL(hostname, clientID string, tls bool) string {
	redirect := ""
	if hostname != "" {
		scheme := "http://"
		if tls {
			scheme = "https://"
		}
		redirect = scheme + hostname
	} else {
		redirect = githubDefaultHostName
	}
	redirect = redirect + "/login/oauth/authorize?client_id=" + clientID + "&scope=repo+admin:repo_hook"
	return redirect
}

func (g *GhProvider) testAndApply(actionName string, action *types.Action, apiContext *types.APIContext) error {
	applyInput := &v3.GithubPipelineConfigApplyInput{}

	if err := json.NewDecoder(apiContext.Request.Body).Decode(applyInput); err != nil {
		return httperror.NewAPIError(httperror.InvalidBodyContent,
			fmt.Sprintf("Failed to parse body: %v", err))
	}

	ns, _ := ref.Parse(apiContext.ID)
	pConfig, err := g.GetProviderConfig(ns)
	if err != nil {
		return err
	}
	storedGithubPipelineConfig, ok := pConfig.(*v3.GithubPipelineConfig)
	if !ok {
		return fmt.Errorf("Failed to get github provider config")
	}
	toUpdate := storedGithubPipelineConfig.DeepCopy()

	if applyInput.InheritAuth {
		globalConfig, err := g.getGithubConfigCR()
		if err != nil {
			return err
		}
		toUpdate.Inherit = true
		toUpdate.ClientID = globalConfig.ClientID
		toUpdate.ClientSecret = globalConfig.ClientSecret
		toUpdate.Hostname = globalConfig.Hostname
		toUpdate.TLS = globalConfig.TLS
	} else {
		toUpdate.ClientID = applyInput.GithubConfig.ClientID
		toUpdate.ClientSecret = applyInput.GithubConfig.ClientSecret
		toUpdate.Hostname = applyInput.GithubConfig.Hostname
		toUpdate.TLS = applyInput.GithubConfig.TLS
	}

	//oauth and add user
	userName := apiContext.Request.Header.Get("Impersonate-User")
	sourceCodeCredential, err := g.authAddAccount(userName, applyInput.Code, toUpdate)
	if err != nil {
		return err
	}
	if _, err = g.refreshReposByCredentialAndConfig(sourceCodeCredential, toUpdate); err != nil {
		return err
	}

	toUpdate.Enabled = true
	//when inherit from global auth, we don't store client secret to project scope
	if toUpdate.Inherit {
		toUpdate.ClientSecret = ""
	}
	//update github pipeline config
	if _, err = g.SourceCodeProviderConfigs.ObjectClient().Update(toUpdate.Name, toUpdate); err != nil {
		return err
	}

	apiContext.WriteResponse(http.StatusOK, nil)
	return nil
}

func (g *GhProvider) authuser(apiContext *types.APIContext) error {
	authUserInput := v3.AuthUserInput{}
	requestBytes, err := ioutil.ReadAll(apiContext.Request.Body)
	if err != nil {
		return err
	}
	if err := json.Unmarshal(requestBytes, &authUserInput); err != nil {
		return err
	}

	ns, _ := ref.Parse(apiContext.ID)
	pConfig, err := g.GetProviderConfig(ns)
	if err != nil {
		return err
	}
	config, ok := pConfig.(*v3.GithubPipelineConfig)
	if !ok {
		return fmt.Errorf("Failed to get github provider config")
	}
	if !config.Enabled {
		return errors.New("github oauth app is not configured")
	}

	//oauth and add user
	userName := apiContext.Request.Header.Get("Impersonate-User")
	account, err := g.authAddAccount(userName, authUserInput.Code, config)
	if err != nil {
		return err
	}
	data := map[string]interface{}{}
	if err := access.ByID(apiContext, apiContext.Version, client.SourceCodeCredentialType, account.Name, &data); err != nil {
		return err
	}

	if _, err := g.refreshReposByCredentialAndConfig(account, config); err != nil {
		return err
	}

	apiContext.WriteResponse(http.StatusOK, data)
	return nil
}

func (g *GhProvider) getGithubConfigCR() (*mv3.GithubConfig, error) {
	authConfigObj, err := g.AuthConfigs.ObjectClient().UnstructuredClient().Get(model.GithubType, metav1.GetOptions{})
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve GithubConfig, error: %v", err)
	}

	u, ok := authConfigObj.(runtime.Unstructured)
	if !ok {
		return nil, fmt.Errorf("failed to retrieve GithubConfig, cannot read k8s Unstructured data")
	}
	storedGithubConfigMap := u.UnstructuredContent()

	storedGithubConfig := &mv3.GithubConfig{}
	if err := mapstructure.Decode(storedGithubConfigMap, storedGithubConfig); err != nil {
		return nil, fmt.Errorf("failed to decode the config, error: %v", err)
	}

	metadataMap, ok := storedGithubConfigMap["metadata"].(map[string]interface{})
	if !ok {
		return nil, fmt.Errorf("failed to retrieve GithubConfig metadata, cannot read k8s Unstructured data")
	}

	typemeta := &metav1.ObjectMeta{}
	//time.Time cannot decode directly
	delete(metadataMap, "creationTimestamp")
	if err := mapstructure.Decode(metadataMap, typemeta); err != nil {
		return nil, fmt.Errorf("failed to decode the config, error: %v", err)
	}
	storedGithubConfig.ObjectMeta = *typemeta

	return storedGithubConfig, nil
}

func (g *GhProvider) authAddAccount(userID string, code string, config *v3.GithubPipelineConfig) (*v3.SourceCodeCredential, error) {
	if userID == "" {
		return nil, errors.New("unauth")
	}

	remote, err := remote.New(config)
	if err != nil {
		return nil, err
	}
	account, err := remote.Login(code)
	if err != nil {
		return nil, err
	}
	account.Name = strings.ToLower(fmt.Sprintf("%s-%s-%s", config.Namespace, model.GithubType, account.Spec.LoginName))
	account.Namespace = userID
	account.Spec.UserName = userID
	account.Spec.ProjectName = config.ProjectName
	_, err = g.SourceCodeCredentials.Create(account)
	if apierror.IsAlreadyExists(err) {
		exist, err := g.SourceCodeCredentialLister.Get(userID, account.Name)
		if err != nil {
			return nil, err
		}
		account.ResourceVersion = exist.ResourceVersion
		return g.SourceCodeCredentials.Update(account)
	} else if err != nil {
		return nil, err
	}
	return account, nil
}

func (g *GhProvider) disableAction(request *types.APIContext) error {
	ns, _ := ref.Parse(request.ID)
	o, err := g.SourceCodeProviderConfigs.ObjectClient().UnstructuredClient().GetNamespaced(ns, model.GithubType, metav1.GetOptions{})
	if err != nil {
		return err
	}
	u, _ := o.(runtime.Unstructured)
	config := u.UnstructuredContent()
	if convert.ToBool(config[client.SourceCodeProviderConfigFieldEnabled]) {
		config[client.SourceCodeProviderConfigFieldEnabled] = false
		if _, err := g.SourceCodeProviderConfigs.ObjectClient().Update(model.GithubType, o); err != nil {
			return err
		}
		if t := convert.ToString(config[projectNameField]); t != "" {
			return g.cleanup(t)
		}
	}

	return nil
}

func (g *GhProvider) cleanup(projectID string) error {
	pipelines, err := g.PipelineIndexer.ByIndex(utils.PipelineByProjectIndex, projectID)
	if err != nil {
		return err
	}
	for _, p := range pipelines {
		pipeline, _ := p.(*v3.Pipeline)
		if err := g.Pipelines.DeleteNamespaced(pipeline.Namespace, pipeline.Name, &metav1.DeleteOptions{}); err != nil {
			return err
		}
	}

	pipelineExecutions, err := g.PipelineExecutionIndexer.ByIndex(utils.PipelineExecutionByProjectIndex, projectID)
	if err != nil {
		return err
	}
	for _, e := range pipelineExecutions {
		execution, _ := e.(*v3.PipelineExecution)
		if err := g.PipelineExecutions.DeleteNamespaced(execution.Namespace, execution.Name, &metav1.DeleteOptions{}); err != nil {
			return err
		}
	}

	crdKey := utils.ProjectNameAndSourceCodeTypeKey(projectID, model.GithubType)
	credentials, err := g.SourceCodeCredentialIndexer.ByIndex(utils.SourceCodeCredentialByProjectAndTypeIndex, crdKey)
	if err != nil {
		return err
	}
	for _, c := range credentials {
		credential, _ := c.(*v3.SourceCodeCredential)
		if err := g.SourceCodeCredentials.DeleteNamespaced(credential.Namespace, credential.Name, &metav1.DeleteOptions{}); err != nil {
			return err
		}
	}

	repoKey := utils.ProjectNameAndSourceCodeTypeKey(projectID, model.GithubType)
	repositories, err := g.SourceCodeRepositoryIndexer.ByIndex(utils.SourceCodeRepositoryByProjectAndTypeIndex, repoKey)
	if err != nil {
		return err
	}
	for _, r := range repositories {
		repo, _ := r.(*v3.SourceCodeRepository)
		if err := g.SourceCodeRepositories.DeleteNamespaced(repo.Namespace, repo.Name, &metav1.DeleteOptions{}); err != nil {
			return err
		}
	}

	return nil
}

func (g *GhProvider) refreshReposByCredentialAndConfig(credential *v3.SourceCodeCredential, config *v3.GithubPipelineConfig) ([]v3.SourceCodeRepository, error) {
	namespace := credential.Namespace
	credentialID := ref.Ref(credential)
	remote, err := remote.New(config)
	if err != nil {
		return nil, err
	}
	repos, err := remote.Repos(credential)
	if err != nil {
		return nil, err
	}

	//remove old repos
	repositories, err := g.SourceCodeRepositoryIndexer.ByIndex(utils.SourceCodeRepositoryByCredentialIndex, credentialID)
	if err != nil {
		return nil, err
	}
	for _, r := range repositories {
		repo, _ := r.(*v3.SourceCodeRepository)
		if err := g.SourceCodeRepositories.DeleteNamespaced(namespace, repo.Name, &metav1.DeleteOptions{}); err != nil {
			return nil, err
		}
	}

	//store new repos
	for _, repo := range repos {
		if !repo.Spec.Permissions.Admin {
			//store only admin repos
			continue
		}
		repo.Spec.SourceCodeCredentialName = credentialID
		repo.Spec.UserName = credential.Spec.UserName
		repo.Spec.SourceCodeType = credential.Spec.SourceCodeType
		repo.Name = uuid.NewV4().String()
		repo.Namespace = namespace
		repo.Spec.ProjectName = credential.Spec.ProjectName
		if _, err := g.SourceCodeRepositories.Create(&repo); err != nil {
			return nil, err
		}
	}

	return repos, nil
}