package api

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

	"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/repository"
)

// 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{
				UpdateTokenCache: app.updateTokenCache,
			},
		},
		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
	}
}

// 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{
				UpdateTokenCache: app.updateTokenCache,
			},
		},
		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
	}

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

// HandleGetReleaseComponents retrieves a single release based on a 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{
				UpdateTokenCache: app.updateTokenCache,
			},
		},
		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.Objects); 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{
				UpdateTokenCache: app.updateTokenCache,
			},
		},
		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
	}
}

// HandleUpgradeRelease upgrades a release with new values.yaml
func (app *App) HandleUpgradeRelease(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.UpgradeReleaseForm{
		ReleaseForm: &forms.ReleaseForm{
			Form: &helm.Form{
				UpdateTokenCache: app.updateTokenCache,
			},
		},
		Name: name,
	}

	form.ReleaseForm.PopulateHelmOptionsFromQueryParams(
		vals,
		app.repo.ServiceAccount,
	)

	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.UpgradeRelease(form.Name, form.Values)

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

		return
	}

	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{
				UpdateTokenCache: app.updateTokenCache,
			},
		},
		Name: name,
	}

	form.ReleaseForm.PopulateHelmOptionsFromQueryParams(
		vals,
		app.repo.ServiceAccount,
	)

	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.ServiceAccountRepository) 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.ServiceAccount)

		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.testing {
		agent = app.TestAgents.HelmAgent
	} else {
		agent, err = helm.GetAgentOutOfClusterConfig(form.Form, app.logger)
	}

	return agent, err
}