package state

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/helmfile/chartify"

	"github.com/helmfile/helmfile/pkg/helmexec"
	"github.com/helmfile/helmfile/pkg/remote"
)

type Dependency struct {
	Chart   string `yaml:"chart"`
	Version string `yaml:"version"`
	Alias   string `yaml:"alias"`
}

func (st *HelmState) appendHelmXFlags(flags []string, release *ReleaseSpec) []string {
	for _, adopt := range release.Adopt {
		flags = append(flags, "--adopt", adopt)
	}

	return flags
}

// append post-renderer flags to helm flags
func (st *HelmState) appendPostRenderFlags(flags []string, release *ReleaseSpec, postRenderer string) []string {
	switch {
	// postRenderer arg comes from cmd flag.
	case release.PostRenderer != nil && *release.PostRenderer != "":
		flags = append(flags, "--post-renderer", *release.PostRenderer)
	case postRenderer != "":
		flags = append(flags, "--post-renderer", postRenderer)
	case st.HelmDefaults.PostRenderer != nil && *st.HelmDefaults.PostRenderer != "":
		flags = append(flags, "--post-renderer", *st.HelmDefaults.PostRenderer)
	}
	return flags
}

type Chartify struct {
	Opts  *chartify.ChartifyOpts
	Clean func()
}

func (st *HelmState) downloadChartWithGoGetter(r *ReleaseSpec) (string, error) {
	return st.goGetterChart(r.Chart, r.Directory, r.CacheDir(), r.ForceGoGetter)
}

// goGetterChart looks for a chart directory in known places, and returns either the full path or an error.
//
// This does not ensure that the chart is well-formed; only that the requested filename exists.
//
// Order of resolution:
// - relative to current working directory
// - if path is absolute or begins with '.', error out here
// - URL
func (st *HelmState) goGetterChart(chart, dir, cacheDir string, force bool) (string, error) {
	if dir != "" && chart == "" {
		chart = dir
	}

	if _, err := st.fs.Stat(chart); err == nil {
		return chart, nil
	}

	if filepath.IsAbs(chart) || strings.HasPrefix(chart, ".") {
		return "", fmt.Errorf("chart path %s not found", chart)
	}

	if strings.HasPrefix(chart, "oci://") {
		return chart, nil
	}

	_, err := remote.Parse(chart)
	if err != nil {
		if force {
			return "", fmt.Errorf("Parsing url from dir failed due to error %q.\nContinuing the process assuming this is a regular Helm chart.", err.Error())
		}
	} else {
		r := remote.NewRemote(st.logger, "", st.fs)

		fetchedDir, err := r.Fetch(chart, cacheDir)
		if err != nil {
			return "", fmt.Errorf("fetching %q: %v", chart, err)
		}

		chart = fetchedDir
	}

	return chart, nil
}

func (st *HelmState) PrepareChartify(helm helmexec.Interface, release *ReleaseSpec, chart string, workerIndex int) (*Chartify, func(), error) {
	c := &Chartify{
		Opts: &chartify.ChartifyOpts{
			WorkaroundOutputDirIssue:    true,
			EnableKustomizeAlphaPlugins: true,
			ChartVersion:                release.Version,
			Namespace:                   release.Namespace,
			ID:                          ReleaseToID(release),
		},
	}

	var filesNeedCleaning []string

	clean := func() {
		st.removeFiles(filesNeedCleaning)
	}

	var shouldRun bool

	dir := chart
	if !filepath.IsAbs(chart) {
		dir = filepath.Join(st.basePath, chart)
	}
	if stat, _ := os.Stat(dir); stat != nil && stat.IsDir() {
		if exists, err := st.fs.FileExists(filepath.Join(dir, "Chart.yaml")); err == nil && !exists {
			shouldRun = true
		}
	}

	for _, d := range release.Dependencies {
		dependenceChart, err := st.goGetterChart(d.Chart, "", release.CacheDir(), release.ForceGoGetter)

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

		if strings.HasPrefix(dependenceChart, ".") {
			dependenceChart, err = st.fs.Abs(dependenceChart)
			if err != nil {
				return nil, clean, err
			}
		}

		c.Opts.AdhocChartDependencies = append(c.Opts.AdhocChartDependencies, chartify.ChartDependency{
			Alias:   d.Alias,
			Chart:   dependenceChart,
			Version: d.Version,
		})

		shouldRun = true
	}

	jsonPatches := release.JSONPatches
	if len(jsonPatches) > 0 {
		generatedFiles, err := st.generateTemporaryReleaseValuesFiles(release, jsonPatches, release.MissingFileHandler)
		if err != nil {
			return nil, clean, err
		}

		filesNeedCleaning = append(filesNeedCleaning, generatedFiles...)

		c.Opts.JsonPatches = append(c.Opts.JsonPatches, generatedFiles...)

		shouldRun = true
	}

	strategicMergePatches := release.StrategicMergePatches
	if len(strategicMergePatches) > 0 {
		generatedFiles, err := st.generateTemporaryReleaseValuesFiles(release, strategicMergePatches, release.MissingFileHandler)
		if err != nil {
			return nil, clean, err
		}

		c.Opts.StrategicMergePatches = append(c.Opts.StrategicMergePatches, generatedFiles...)

		filesNeedCleaning = append(filesNeedCleaning, generatedFiles...)

		shouldRun = true
	}

	transformers := release.Transformers
	if len(transformers) > 0 {
		generatedFiles, err := st.generateTemporaryReleaseValuesFiles(release, transformers, release.MissingFileHandler)
		if err != nil {
			return nil, clean, err
		}

		c.Opts.Transformers = append(c.Opts.Transformers, generatedFiles...)

		filesNeedCleaning = append(filesNeedCleaning, generatedFiles...)

		shouldRun = true
	}

	if release.ForceNamespace != "" {
		c.Opts.OverrideNamespace = release.ForceNamespace

		shouldRun = true
	}

	if shouldRun {
		st.logger.Debugf("Chartify process for %s", dir)
		generatedFiles, err := st.generateValuesFiles(helm, release, workerIndex)
		if err != nil {
			return nil, clean, err
		}

		filesNeedCleaning = append(filesNeedCleaning, generatedFiles...)

		c.Opts.ValuesFiles = generatedFiles
		setFlags, err := st.setFlags(release.SetValues)
		if err != nil {
			return nil, clean, fmt.Errorf("rendering set value entry for release %s: %v", release.Name, err)
		}
		c.Opts.SetFlags = setFlags
		c.Opts.TemplateData = st.newReleaseTemplateData(release)
		c.Opts.TemplateFuncs = st.newReleaseTemplateFuncMap(dir)

		return c, clean, nil
	}

	return nil, clean, nil
}