package handlers

import (
	"errors"
	"fmt"
	"github.com/hexops/gotextdiff"
	"github.com/hexops/gotextdiff/myers"
	"github.com/hexops/gotextdiff/span"
	"github.com/joomcode/errorx"
	"github.com/komodorio/helm-dashboard/pkg/dashboard/objects"
	"github.com/rogpeppe/go-internal/semver"
	log "github.com/sirupsen/logrus"
	"gopkg.in/yaml.v3"
	"helm.sh/helm/v3/pkg/chartutil"
	"helm.sh/helm/v3/pkg/release"
	"helm.sh/helm/v3/pkg/repo"
	helmtime "helm.sh/helm/v3/pkg/time"
	"net/http"
	"sort"
	"strconv"

	"github.com/gin-gonic/gin"
	"github.com/komodorio/helm-dashboard/pkg/dashboard/utils"
)

type HelmHandler struct {
	*Contexted
}

func (h *HelmHandler) getRelease(c *gin.Context) *objects.Release {
	app := h.GetApp(c)
	if app == nil {
		return nil
	}

	rel, err := app.Releases.ByName(c.Param("ns"), c.Param("name"))
	if err != nil {
		_ = c.AbortWithError(http.StatusBadRequest, err)
		return nil
	}
	return rel
}

func (h *HelmHandler) GetReleases(c *gin.Context) {
	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	rels, err := app.Releases.List()
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	res := []*ReleaseElement{}
	for _, r := range rels {
		res = append(res, HReleaseToJSON(r.Orig))
	}

	c.IndentedJSON(http.StatusOK, res)
}

func (h *HelmHandler) Uninstall(c *gin.Context) {
	rel := h.getRelease(c)
	if rel == nil {
		return // error state is set inside
	}

	err := rel.Uninstall()
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.Status(http.StatusAccepted)
}

func (h *HelmHandler) Rollback(c *gin.Context) {
	rel := h.getRelease(c)
	if rel == nil {
		return // error state is set inside
	}

	revn, err := strconv.Atoi(c.PostForm("revision"))
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	err = rel.Rollback(revn)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.Status(http.StatusAccepted)
}

func (h *HelmHandler) History(c *gin.Context) {
	rel := h.getRelease(c)
	if rel == nil {
		return // error state is set inside
	}

	revs, err := rel.History()
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	res := []*HistoryElement{}
	for _, r := range revs {
		res = append(res, HReleaseToHistElem(r.Orig))
	}

	sort.Slice(res, func(i, j int) bool {
		return res[i].Revision < res[j].Revision
	})

	c.IndentedJSON(http.StatusOK, res)
}

func (h *HelmHandler) Resources(c *gin.Context) {
	h.EnableClientCache(c)

	rel := h.getRelease(c)
	if rel == nil {
		return // error state is set inside
	}

	res, err := objects.ParseManifests(rel.Orig.Manifest)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	c.IndentedJSON(http.StatusOK, res)
}

func (h *HelmHandler) RepoVersions(c *gin.Context) {
	qp, err := utils.GetQueryProps(c)
	if err != nil {
		_ = c.AbortWithError(http.StatusBadRequest, err)
		return
	}

	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	repos, err := app.Repositories.Containing(qp.Name)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	res := []*RepoChartElement{}
	for _, r := range repos {
		res = append(res, &RepoChartElement{
			Name:        r.Name,
			Version:     r.Version,
			AppVersion:  r.AppVersion,
			Description: r.Description,
			Repository:  r.Annotations[objects.AnnRepo],
		})
	}

	c.IndentedJSON(http.StatusOK, res)
}

func (h *HelmHandler) RepoLatestVer(c *gin.Context) {
	qp, err := utils.GetQueryProps(c)
	if err != nil {
		_ = c.AbortWithError(http.StatusBadRequest, err)
		return
	}

	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	rep, err := app.Repositories.Containing(qp.Name)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	res := []*RepoChartElement{}
	for _, r := range rep {
		res = append(res, &RepoChartElement{
			Name:        r.Name,
			Version:     r.Version,
			AppVersion:  r.AppVersion,
			Description: r.Description,
			Repository:  r.Annotations[objects.AnnRepo],
		})
	}

	sort.Slice(res, func(i, j int) bool {
		return semver.Compare(res[i].Version, res[j].Version) > 0
	})

	if len(res) > 0 {
		c.IndentedJSON(http.StatusOK, res[:1])
	} else {
		c.Status(http.StatusNoContent)
	}
}

func (h *HelmHandler) RepoCharts(c *gin.Context) {
	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	rep, err := app.Repositories.Get(c.Param("name"))
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	charts, err := rep.Charts()
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	installed, err := app.Releases.List()
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	// TODO: enrich with installed
	enrichRepoChartsWithInstalled(charts, installed)

	sort.Slice(charts, func(i, j int) bool {
		return charts[i].Name < charts[j].Name
	})

	c.IndentedJSON(http.StatusOK, charts)
}

func enrichRepoChartsWithInstalled(charts []*repo.ChartVersion, installed []*objects.Release) {
	for _, rchart := range charts {
		for _, rel := range installed {
			if rchart.Metadata.Name == rel.Orig.Chart.Name() {
				log.Debugf("Matched") // TODO: restore implementation
				// TODO: there can be more than one
				//rchart.InstalledNamespace = rel.Orig.Namespace
				//rchart.InstalledName = rel.Orig.Name
			}
		}
	}
}

func (h *HelmHandler) RepoUpdate(c *gin.Context) {
	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	rep, err := app.Repositories.Get(c.Param("name"))
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	err = rep.Update()
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.Status(http.StatusNoContent)
}

func (h *HelmHandler) Install(c *gin.Context) {
	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	values := map[string]interface{}{}
	err := yaml.Unmarshal([]byte(c.PostForm("values")), &values)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	justTemplate := c.PostForm("preview") == "true"
	ns := c.Param("ns")
	if ns == "[empty]" {
		ns = ""
	}
	rel, err := app.Releases.Install(ns, c.PostForm("name"), c.PostForm("chart"), c.PostForm("version"), justTemplate, values)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	if justTemplate {
		c.IndentedJSON(http.StatusOK, rel)
	} else {
		c.IndentedJSON(http.StatusAccepted, rel)
	}
}

func (h *HelmHandler) Upgrade(c *gin.Context) {
	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	existing, err := app.Releases.ByName(c.Param("ns"), c.Param("name"))
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	values := map[string]interface{}{}
	err = yaml.Unmarshal([]byte(c.PostForm("values")), &values)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	justTemplate := c.PostForm("preview") == "true"
	rel, err := existing.Upgrade(c.PostForm("chart"), c.PostForm("version"), justTemplate, values)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	if justTemplate {
		c.IndentedJSON(http.StatusOK, rel)
	} else {
		c.IndentedJSON(http.StatusAccepted, rel)
	}
}

func (h *HelmHandler) RunTests(c *gin.Context) {
	rel := h.getRelease(c)
	if rel == nil {
		return // error state is set inside
	}

	out, err := rel.RunTests()
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.String(http.StatusOK, out)
}

func (h *HelmHandler) GetInfoSection(c *gin.Context) {
	if c.Query("revision") != "" { // don't cache if latest is requested
		h.EnableClientCache(c)
	}

	rel := h.getRelease(c)
	if rel == nil {
		return // error state is set inside
	}

	revn, err := strconv.Atoi(c.Query("revision"))
	if c.Query("revision") != "" && err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	rev, err := rel.GetRev(revn)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	var revDiff *objects.Release
	revS := c.Query("revisionDiff")
	if revS != "" {
		revN, err := strconv.Atoi(revS)
		if err != nil {
			_ = c.AbortWithError(http.StatusInternalServerError, err)
			return
		}

		revDiff, err = rel.GetRev(revN)
		if err != nil {
			_ = c.AbortWithError(http.StatusInternalServerError, err)
			return
		}
	}

	flag := c.Query("userDefined") == "true"

	res, err := h.handleGetSection(rev, c.Param("section"), revDiff, flag)
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.String(http.StatusOK, res)
}

func (h *HelmHandler) RepoValues(c *gin.Context) {
	h.EnableClientCache(c)

	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	out, err := app.Repositories.GetChartValues(c.Query("chart"), c.Query("version"))
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	c.String(http.StatusOK, out)
}

func (h *HelmHandler) RepoList(c *gin.Context) {
	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	repos, err := app.Repositories.List()
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}

	out := []RepositoryElement{}
	for _, r := range repos {
		out = append(out, RepositoryElement{
			Name: r.Orig.Name,
			URL:  r.Orig.URL,
		})
	}

	c.IndentedJSON(http.StatusOK, out)
}

func (h *HelmHandler) RepoAdd(c *gin.Context) {
	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	// TODO: more repo options to accept
	err := app.Repositories.Add(c.PostForm("name"), c.PostForm("url"))
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.Status(http.StatusNoContent)
}

func (h *HelmHandler) RepoDelete(c *gin.Context) {
	app := h.GetApp(c)
	if app == nil {
		return // sets error inside
	}

	err := app.Repositories.Delete(c.Param("name"))
	if err != nil {
		_ = c.AbortWithError(http.StatusInternalServerError, err)
		return
	}
	c.Status(http.StatusNoContent)
}

func (h *HelmHandler) handleGetSection(rel *objects.Release, section string, rDiff *objects.Release, flag bool) (string, error) {
	sections := map[string]objects.SectionFn{
		"manifests": func(qp *release.Release, b bool) (string, error) { return qp.Manifest, nil },
		"notes":     func(qp *release.Release, b bool) (string, error) { return qp.Info.Notes, nil },
		"values": func(qp *release.Release, b bool) (string, error) {
			allVals := qp.Config

			if !b {
				merged, err := chartutil.CoalesceValues(qp.Chart, qp.Config)
				if err != nil {
					return "", errorx.Decorate(err, "failed to merge chart vals with user defined")
				}
				allVals = merged
			}

			if len(allVals) > 0 {
				data, err := yaml.Marshal(allVals)
				if err != nil {
					return "", errorx.Decorate(err, "failed to serialize values into YAML")
				}
				return string(data), nil
			}
			return "", nil
		},
	}

	functor, found := sections[section]
	if !found {
		return "", errors.New("unsupported section: " + section)
	}

	if rDiff != nil {
		ext := ".yaml"
		if section == "notes" {
			ext = ".txt"
		}

		res, err := RevisionDiff(functor, ext, rDiff.Orig, rel.Orig, flag)
		if err != nil {
			return "", err
		}
		return res, nil
	}

	res, err := functor(rel.Orig, flag)
	if err != nil {
		return "", errorx.Decorate(err, "failed to get section info")
	}
	return res, nil
}

type RepoChartElement struct {
	Name        string `json:"name"`
	Version     string `json:"version"`
	AppVersion  string `json:"app_version"`
	Description string `json:"description"`

	InstalledNamespace string `json:"installed_namespace"`
	InstalledName      string `json:"installed_name"`
	Repository         string `json:"repository"`
}

func HReleaseToJSON(o *release.Release) *ReleaseElement {
	return &ReleaseElement{
		Name:         o.Name,
		Namespace:    o.Namespace,
		Revision:     strconv.Itoa(o.Version),
		Updated:      o.Info.LastDeployed,
		Status:       o.Info.Status,
		Chart:        fmt.Sprintf("%s-%s", o.Chart.Name(), o.Chart.Metadata.Version),
		ChartName:    o.Chart.Name(),
		ChartVersion: o.Chart.Metadata.Version,
		AppVersion:   o.Chart.AppVersion(),
		Icon:         o.Chart.Metadata.Icon,
		Description:  o.Chart.Metadata.Description,
	}
}

type ReleaseElement struct {
	Name         string         `json:"name"`
	Namespace    string         `json:"namespace"`
	Revision     string         `json:"revision"`
	Updated      helmtime.Time  `json:"updated"`
	Status       release.Status `json:"status"`
	Chart        string         `json:"chart"`
	ChartName    string         `json:"chartName"`
	ChartVersion string         `json:"chartVersion"`
	AppVersion   string         `json:"app_version"`
	Icon         string         `json:"icon"`
	Description  string         `json:"description"`
}

type RepositoryElement struct {
	Name string `json:"name"`
	URL  string `json:"url"`
}

type HistoryElement struct {
	Revision    int            `json:"revision"`
	Updated     helmtime.Time  `json:"updated"`
	Status      release.Status `json:"status"`
	Chart       string         `json:"chart"`
	AppVersion  string         `json:"app_version"`
	Description string         `json:"description"`

	ChartName string `json:"chart_name"` // custom addition on top of Helm
	ChartVer  string `json:"chart_ver"`  // custom addition on top of Helm
	HasTests  bool   `json:"has_tests"`
}

func HReleaseToHistElem(o *release.Release) *HistoryElement {
	return &HistoryElement{
		Revision:    o.Version,
		Updated:     o.Info.LastDeployed,
		Status:      o.Info.Status,
		Chart:       fmt.Sprintf("%s-%s", o.Chart.Name(), o.Chart.Metadata.Version),
		AppVersion:  o.Chart.AppVersion(),
		Description: o.Info.Description,
		ChartName:   o.Chart.Name(),
		ChartVer:    o.Chart.Metadata.Version,
		HasTests:    releaseHasTests(o),
	}
}

func RevisionDiff(functor objects.SectionFn, ext string, revision1 *release.Release, revision2 *release.Release, flag bool) (string, error) {
	if revision1 == nil || revision2 == nil {
		log.Debugf("One of revisions is nil: %v %v", revision1, revision2)
		return "", nil
	}

	manifest1, err := functor(revision1, flag)
	if err != nil {
		return "", err
	}

	manifest2, err := functor(revision2, flag)
	if err != nil {
		return "", err
	}

	diff := GetDiff(manifest1, manifest2, strconv.Itoa(revision1.Version)+ext, strconv.Itoa(revision2.Version)+ext)
	return diff, nil
}

func GetDiff(text1 string, text2 string, name1 string, name2 string) string {
	edits := myers.ComputeEdits(span.URIFromPath(""), text1, text2)
	unified := gotextdiff.ToUnified(name1, name2, text1, edits)
	diff := fmt.Sprint(unified)
	log.Debugf("The diff is: %s", diff)
	return diff
}

func releaseHasTests(o *release.Release) bool {
	for _, h := range o.Hooks {
		for _, e := range h.Events {
			if e == release.HookTest {
				return true
			}
		}
	}
	return false
}