package api

import (
	"encoding/json"
	"fmt"
	"net/http"
	"net/url"
	"strconv"
	"strings"

	"github.com/porter-dev/porter/internal/kubernetes/prometheus"
	"github.com/porter-dev/porter/internal/models"
	"github.com/porter-dev/porter/internal/templater/parser"
	"helm.sh/helm/v3/pkg/release"

	"github.com/go-chi/chi"
	"github.com/porter-dev/porter/internal/forms"
	"github.com/porter-dev/porter/internal/helm"
	"github.com/porter-dev/porter/internal/helm/grapher"
	"github.com/porter-dev/porter/internal/kubernetes"
	"github.com/porter-dev/porter/internal/repository"
	segment "gopkg.in/segmentio/analytics-go.v3"
)

// Enumeration of release API error codes, represented as int64
const (
	ErrReleaseDecode ErrorCode = iota + 600
	ErrReleaseValidateFields
	ErrReleaseReadData
	ErrReleaseDeploy
)

// HandleListReleases retrieves a list of releases for a cluster
// with various filter options
func (app *App) HandleListReleases(w http.ResponseWriter, r *http.Request) {
	form := &forms.ListReleaseForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		ListFilter: &helm.ListFilter{},
	}

	agent, err := app.getAgentFromQueryParams(
		w,
		r,
		form.ReleaseForm,
		form.ReleaseForm.PopulateHelmOptionsFromQueryParams,
		form.PopulateListFromQueryParams,
	)

	// errors are handled in app.getAgentFromQueryParams
	if err != nil {
		return
	}

	releases, err := agent.ListReleases(form.Namespace, form.ListFilter)

	if err != nil {
		app.handleErrorRead(err, ErrReleaseReadData, w)
		return
	}

	if err := json.NewEncoder(w).Encode(releases); err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}
}

// PorterRelease is a helm release with a form attached
type PorterRelease struct {
	*release.Release
	Form       *models.FormYAML `json:"form"`
	HasMetrics bool             `json:"has_metrics"`
}

// HandleGetRelease retrieves a single release based on a name and revision
func (app *App) HandleGetRelease(w http.ResponseWriter, r *http.Request) {
	name := chi.URLParam(r, "name")
	revision, err := strconv.ParseUint(chi.URLParam(r, "revision"), 0, 64)

	form := &forms.GetReleaseForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		Name:     name,
		Revision: int(revision),
	}

	agent, err := app.getAgentFromQueryParams(
		w,
		r,
		form.ReleaseForm,
		form.ReleaseForm.PopulateHelmOptionsFromQueryParams,
	)

	// errors are handled in app.getAgentFromQueryParams
	if err != nil {
		return
	}

	release, err := agent.GetRelease(form.Name, form.Revision)

	if err != nil {
		app.sendExternalError(err, http.StatusNotFound, HTTPError{
			Code:   ErrReleaseReadData,
			Errors: []string{"release not found"},
		}, w)

		return
	}

	// get the filter options
	k8sForm := &forms.K8sForm{
		OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
			Repo:              app.Repo,
			DigitalOceanOAuth: app.DOConf,
		},
	}

	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	k8sForm.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)
	k8sForm.DefaultNamespace = form.ReleaseForm.Namespace

	// validate the form
	if err := app.validator.Struct(k8sForm); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new dynamic client
	dynClient, err := kubernetes.GetDynamicClientOutOfClusterConfig(k8sForm.OutOfClusterConfig)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	parserDef := &parser.ClientConfigDefault{
		DynamicClient: dynClient,
		HelmChart:     release.Chart,
		HelmRelease:   release,
	}

	res := &PorterRelease{release, nil, false}

	for _, file := range release.Chart.Files {
		if strings.Contains(file.Name, "form.yaml") {
			formYAML, err := parser.FormYAMLFromBytes(parserDef, file.Data, "")

			if err != nil {
				break
			}

			res.Form = formYAML
			break
		}
	}

	// if form not populated, detect common charts
	if res.Form == nil {
		// for now just case by name
		if res.Release.Chart.Name() == "velero" {
			formYAML, err := parser.FormYAMLFromBytes(parserDef, []byte(veleroForm), "")

			if err == nil {
				res.Form = formYAML
			}
		}
	}

	// get prometheus service
	_, found, err := prometheus.GetPrometheusService(agent.K8sAgent.Clientset)

	if err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	res.HasMetrics = found

	if err := json.NewEncoder(w).Encode(res); err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}
}

// HandleGetReleaseComponents retrieves kubernetes objects listed in a release identified by name and revision
func (app *App) HandleGetReleaseComponents(w http.ResponseWriter, r *http.Request) {
	name := chi.URLParam(r, "name")
	revision, err := strconv.ParseUint(chi.URLParam(r, "revision"), 0, 64)

	form := &forms.GetReleaseForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		Name:     name,
		Revision: int(revision),
	}

	agent, err := app.getAgentFromQueryParams(
		w,
		r,
		form.ReleaseForm,
		form.ReleaseForm.PopulateHelmOptionsFromQueryParams,
	)

	// errors are handled in app.getAgentFromQueryParams
	if err != nil {
		return
	}

	release, err := agent.GetRelease(form.Name, form.Revision)

	if err != nil {
		app.sendExternalError(err, http.StatusNotFound, HTTPError{
			Code:   ErrReleaseReadData,
			Errors: []string{"release not found"},
		}, w)

		return
	}

	yamlArr := grapher.ImportMultiDocYAML([]byte(release.Manifest))
	objects := grapher.ParseObjs(yamlArr)

	parsed := grapher.ParsedObjs{
		Objects: objects,
	}

	parsed.GetControlRel()
	parsed.GetLabelRel()
	parsed.GetSpecRel()

	if err := json.NewEncoder(w).Encode(parsed); err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}
}

// HandleGetReleaseControllers retrieves controllers that belong to a release.
// Used to display status of charts.
func (app *App) HandleGetReleaseControllers(w http.ResponseWriter, r *http.Request) {
	name := chi.URLParam(r, "name")
	revision, err := strconv.ParseUint(chi.URLParam(r, "revision"), 0, 64)

	form := &forms.GetReleaseForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		Name:     name,
		Revision: int(revision),
	}

	agent, err := app.getAgentFromQueryParams(
		w,
		r,
		form.ReleaseForm,
		form.ReleaseForm.PopulateHelmOptionsFromQueryParams,
	)

	// errors are handled in app.getAgentFromQueryParams
	if err != nil {
		return
	}

	release, err := agent.GetRelease(form.Name, form.Revision)

	if err != nil {
		app.sendExternalError(err, http.StatusNotFound, HTTPError{
			Code:   ErrReleaseReadData,
			Errors: []string{"release not found"},
		}, w)

		return
	}

	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	// get the filter options
	k8sForm := &forms.K8sForm{
		OutOfClusterConfig: &kubernetes.OutOfClusterConfig{
			Repo:              app.Repo,
			DigitalOceanOAuth: app.DOConf,
		},
	}

	k8sForm.PopulateK8sOptionsFromQueryParams(vals, app.Repo.Cluster)

	// validate the form
	if err := app.validator.Struct(k8sForm); err != nil {
		app.handleErrorFormValidation(err, ErrK8sValidate, w)
		return
	}

	// create a new kubernetes agent
	var k8sAgent *kubernetes.Agent

	if app.ServerConf.IsTesting {
		k8sAgent = app.TestAgents.K8sAgent
	} else {
		k8sAgent, err = kubernetes.GetAgentOutOfClusterConfig(k8sForm.OutOfClusterConfig)
	}

	yamlArr := grapher.ImportMultiDocYAML([]byte(release.Manifest))
	controllers := grapher.ParseControllers(yamlArr)
	retrievedControllers := []interface{}{}

	// get current status of each controller
	// TODO: refactor with type assertion
	for _, c := range controllers {
		c.Namespace = form.ReleaseForm.Form.Namespace
		switch c.Kind {
		case "Deployment":
			rc, err := k8sAgent.GetDeployment(c)

			if err != nil {
				app.handleErrorDataRead(err, w)
				return
			}

			rc.Kind = c.Kind
			retrievedControllers = append(retrievedControllers, rc)
		case "StatefulSet":
			rc, err := k8sAgent.GetStatefulSet(c)

			if err != nil {
				app.handleErrorDataRead(err, w)
				return
			}

			rc.Kind = c.Kind
			retrievedControllers = append(retrievedControllers, rc)
		case "DaemonSet":
			rc, err := k8sAgent.GetDaemonSet(c)

			if err != nil {
				app.handleErrorDataRead(err, w)
				return
			}

			rc.Kind = c.Kind
			retrievedControllers = append(retrievedControllers, rc)
		case "ReplicaSet":
			rc, err := k8sAgent.GetReplicaSet(c)

			if err != nil {
				app.handleErrorDataRead(err, w)
				return
			}

			rc.Kind = c.Kind
			retrievedControllers = append(retrievedControllers, rc)
		case "CronJob":
			rc, err := k8sAgent.GetCronJob(c)

			if err != nil {
				app.handleErrorDataRead(err, w)
				return
			}

			rc.Kind = c.Kind
			retrievedControllers = append(retrievedControllers, rc)
		}
	}

	if err := json.NewEncoder(w).Encode(retrievedControllers); err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}
}

// HandleListReleaseHistory retrieves a history of releases based on a release name
func (app *App) HandleListReleaseHistory(w http.ResponseWriter, r *http.Request) {
	name := chi.URLParam(r, "name")

	form := &forms.ListReleaseHistoryForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		Name: name,
	}

	agent, err := app.getAgentFromQueryParams(
		w,
		r,
		form.ReleaseForm,
		form.ReleaseForm.PopulateHelmOptionsFromQueryParams,
	)

	// errors are handled in app.getAgentFromQueryParams
	if err != nil {
		return
	}

	release, err := agent.GetReleaseHistory(form.Name)

	if err != nil {
		app.sendExternalError(err, http.StatusNotFound, HTTPError{
			Code:   ErrReleaseReadData,
			Errors: []string{"release not found"},
		}, w)

		return
	}

	if err := json.NewEncoder(w).Encode(release); err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}
}

// HandleGetReleaseToken retrieves the webhook token of a specific release.
func (app *App) HandleGetReleaseToken(w http.ResponseWriter, r *http.Request) {
	name := chi.URLParam(r, "name")

	vals, err := url.ParseQuery(r.URL.RawQuery)
	namespace := vals["namespace"][0]

	clusterID, err := strconv.ParseUint(vals["cluster_id"][0], 10, 64)

	if err != nil {
		app.sendExternalError(err, http.StatusInternalServerError, HTTPError{
			Code:   ErrReleaseReadData,
			Errors: []string{"release not found"},
		}, w)
	}

	release, err := app.Repo.Release.ReadRelease(uint(clusterID), name, namespace)

	if err != nil {
		app.sendExternalError(err, http.StatusInternalServerError, HTTPError{
			Code:   ErrReleaseReadData,
			Errors: []string{"release not found"},
		}, w)
	}

	releaseExt := release.Externalize()

	if err := json.NewEncoder(w).Encode(releaseExt); err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}
}

// HandleUpgradeRelease upgrades a release with new values.yaml
func (app *App) HandleUpgradeRelease(w http.ResponseWriter, r *http.Request) {
	projID, err := strconv.ParseUint(chi.URLParam(r, "project_id"), 0, 64)

	if err != nil || projID == 0 {
		app.handleErrorFormDecoding(err, ErrProjectDecode, w)
		return
	}

	name := chi.URLParam(r, "name")

	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	form := &forms.UpgradeReleaseForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		Name: name,
	}

	form.ReleaseForm.PopulateHelmOptionsFromQueryParams(
		vals,
		app.Repo.Cluster,
	)

	if err := json.NewDecoder(r.Body).Decode(form); err != nil {
		app.handleErrorFormDecoding(err, ErrUserDecode, w)
		return
	}

	agent, err := app.getAgentFromReleaseForm(
		w,
		r,
		form.ReleaseForm,
	)

	// errors are handled in app.getAgentFromBodyParams
	if err != nil {
		return
	}

	registries, err := app.Repo.Registry.ListRegistriesByProjectID(uint(projID))

	if err != nil {
		app.handleErrorDataRead(err, w)
		return
	}

	conf := &helm.UpgradeReleaseConfig{
		Name:       form.Name,
		Cluster:    form.ReleaseForm.Cluster,
		Repo:       *app.Repo,
		Registries: registries,
	}

	_, err = agent.UpgradeRelease(conf, form.Values, app.DOConf)

	if err != nil {
		app.sendExternalError(err, http.StatusInternalServerError, HTTPError{
			Code:   ErrReleaseDeploy,
			Errors: []string{"error upgrading release " + err.Error()},
		}, w)

		return
	}

	w.WriteHeader(http.StatusOK)
}

// HandleReleaseDeployWebhook upgrades a release when a chart specific webhook is called.
func (app *App) HandleReleaseDeployWebhook(w http.ResponseWriter, r *http.Request) {
	token := chi.URLParam(r, "token")

	// retrieve release by token
	release, err := app.Repo.Release.ReadReleaseByWebhookToken(token)

	if err != nil {
		app.sendExternalError(err, http.StatusInternalServerError, HTTPError{
			Code:   ErrReleaseReadData,
			Errors: []string{"release not found with given webhook"},
		}, w)

		return
	}

	params := map[string][]string{}
	params["cluster_id"] = []string{fmt.Sprint(release.ClusterID)}
	params["storage"] = []string{"secret"}
	params["namespace"] = []string{release.Namespace}

	vals, err := url.ParseQuery(r.URL.RawQuery)

	commit := vals["commit"][0]
	repository := vals["repository"][0]

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	form := &forms.UpgradeReleaseForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		Name: release.Name,
	}

	form.ReleaseForm.PopulateHelmOptionsFromQueryParams(
		params,
		app.Repo.Cluster,
	)

	agent, err := app.getAgentFromReleaseForm(
		w,
		r,
		form.ReleaseForm,
	)

	// errors are handled in app.getAgentFromBodyParams
	if err != nil {
		return
	}

	image := map[string]interface{}{}
	image["repository"] = repository
	image["tag"] = commit

	rel, err := agent.GetRelease(form.Name, 0)
	rel.Config["image"] = image

	registries, err := app.Repo.Registry.ListRegistriesByProjectID(uint(form.ReleaseForm.Cluster.ProjectID))

	if err != nil {
		app.handleErrorDataRead(err, w)
		return
	}

	conf := &helm.UpgradeReleaseConfig{
		Name:       form.Name,
		Cluster:    form.ReleaseForm.Cluster,
		Repo:       *app.Repo,
		Registries: registries,
		Values:     rel.Config,
	}

	_, err = agent.UpgradeReleaseByValues(conf, app.DOConf)

	if err != nil {
		app.sendExternalError(err, http.StatusInternalServerError, HTTPError{
			Code:   ErrReleaseDeploy,
			Errors: []string{"error upgrading release " + err.Error()},
		}, w)

		return
	}

	client := *app.segmentClient
	client.Enqueue(segment.Track{
		UserId: "anonymous",
		Event:  "Triggered Re-deploy via Webhook",
		Properties: segment.NewProperties().
			Set("repository", repository),
	})

	w.WriteHeader(http.StatusOK)
}

// HandleRollbackRelease rolls a release back to a specified revision
func (app *App) HandleRollbackRelease(w http.ResponseWriter, r *http.Request) {
	name := chi.URLParam(r, "name")

	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return
	}

	form := &forms.RollbackReleaseForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				Repo:              app.Repo,
				DigitalOceanOAuth: app.DOConf,
			},
		},
		Name: name,
	}

	form.ReleaseForm.PopulateHelmOptionsFromQueryParams(
		vals,
		app.Repo.Cluster,
	)

	if err := json.NewDecoder(r.Body).Decode(form); err != nil {
		app.handleErrorFormDecoding(err, ErrUserDecode, w)
		return
	}

	agent, err := app.getAgentFromReleaseForm(
		w,
		r,
		form.ReleaseForm,
	)

	// errors are handled in app.getAgentFromBodyParams
	if err != nil {
		return
	}

	err = agent.RollbackRelease(form.Name, form.Revision)

	if err != nil {
		app.sendExternalError(err, http.StatusInternalServerError, HTTPError{
			Code:   ErrReleaseDeploy,
			Errors: []string{"error rolling back release " + err.Error()},
		}, w)

		return
	}

	w.WriteHeader(http.StatusOK)
}

// ------------------------ Release handler helper functions ------------------------ //

// getAgentFromQueryParams uses the query params to populate a form, and then
// passes that form to the underlying app.getAgentFromReleaseForm to create a new
// Helm agent.
func (app *App) getAgentFromQueryParams(
	w http.ResponseWriter,
	r *http.Request,
	form *forms.ReleaseForm,
	// populate uses the query params to populate a form
	populate ...func(vals url.Values, repo repository.ClusterRepository) error,
) (*helm.Agent, error) {
	vals, err := url.ParseQuery(r.URL.RawQuery)

	if err != nil {
		app.handleErrorFormDecoding(err, ErrReleaseDecode, w)
		return nil, err
	}

	for _, f := range populate {
		err := f(vals, app.Repo.Cluster)

		if err != nil {
			return nil, err
		}
	}

	return app.getAgentFromReleaseForm(w, r, form)
}

// getAgentFromReleaseForm uses a non-validated form to construct a new Helm agent based on
// the userID found in the session and the options required by the Helm agent.
func (app *App) getAgentFromReleaseForm(
	w http.ResponseWriter,
	r *http.Request,
	form *forms.ReleaseForm,
) (*helm.Agent, error) {
	var err error

	// validate the form
	if err := app.validator.Struct(form); err != nil {
		app.handleErrorFormValidation(err, ErrReleaseValidateFields, w)
		return nil, err
	}

	// create a new agent
	var agent *helm.Agent

	if app.ServerConf.IsTesting {
		agent = app.TestAgents.HelmAgent
	} else {
		agent, err = helm.GetAgentOutOfClusterConfig(form.Form, app.Logger)
	}

	return agent, err
}

const veleroForm string = `tags:
- hello
tabs:
- name: main
  context:
    type: cluster
    config:
      group: velero.io
      version: v1
      resource: backups
  label: Backups
  sections:
  - name: section_one
    contents: 
    - type: heading
      label: 💾 Velero Backups
    - type: resource-list
      value: |
        .items[] | { 
          name: .metadata.name, 
          label: .metadata.namespace,
          status: .status.phase,
          timestamp: .status.completionTimestamp,
          message: [
            (if .status.volumeSnapshotsAttempted then "\(.status.volumeSnapshotsAttempted) volume snapshots attempted, \(.status.volumeSnapshotsCompleted) completed." else null end),
            "Finished \(.status.completionTimestamp).",
            "Backup expires on \(.status.expiration)."
          ]|join(" "),
          data: {
            "Included Namespaces": (if .spec.includedNamespaces then .spec.includedNamespaces|join(",") else "* (all)" end),
            "Included Resources": (if .spec.includedResources then .spec.includedResources|join(",") else "* (all)" end),
            "Storage Location": .spec.storageLocation
          }
        }`