package pull

import (
	"archive/zip"
	"context"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"

	"code.geekeey.de/actions/sdk"
	"code.geekeey.de/actions/sdk/artifact"
)

type Action struct {
	*sdk.Action
}

func New(action *sdk.Action) *Action {
	return &Action{Action: action}
}

type Config struct {
	Name string
	Path string
}

func ParseConfig(get func(string) string) (*Config, error) {
	name := get("name")
	if len(name) == 0 {
		return nil, fmt.Errorf("input 'name': is empty")
	}

	path := get("path")
	if len(path) == 0 {
		path = "."
	}
	return &Config{Name: name, Path: path}, nil
}

func (a *Action) Run(ctx context.Context) error {
	cfg, err := ParseConfig(a.GetInput)
	if err != nil {
		return err
	}

	run, job, err := artifact.JobInfo()
	if err != nil {
		return fmt.Errorf("unable to get job info: %v", err)
	}

	client := artifact.NewClientFromEnv(os.Getenv)

	signed, err := client.GetSignedArtifactURL(ctx, artifact.GetSignedArtifactURLRequest{
		RunID:    run,
		JobRunID: job,
		Name:     cfg.Name,
	})
	if err != nil {
		return fmt.Errorf("cannot get signed artifact URL: %w", err)
	}
	if signed.SignedUrl == "" {
		return fmt.Errorf("no signed URL for artifact %q", cfg.Name)
	}

	tmp, err := os.CreateTemp("", "artifact-*.zip")
	if err != nil {
		return fmt.Errorf("cannot create temporary file: %w", err)
	}
	defer os.Remove(tmp.Name())
	defer tmp.Close()

	res, err := artifact.PullBlob(ctx, nil, tmp, signed.SignedUrl)
	if err != nil {
		return fmt.Errorf("cannot download artifact: %w", err)
	}

	if err := ExtractArchive(tmp.Name(), cfg.Path); err != nil {
		return fmt.Errorf("cannot extract artifact: %w", err)
	}

	a.Noticef("downloaded artifact %s (%d bytes)", cfg.Name, res.Size)
	return nil
}

// ExtractArchive extracts the zip file at zipPath into dest. Entries that would
// escape dest are rejected.
func ExtractArchive(zipPath, dest string) error {
	r, err := zip.OpenReader(zipPath)
	if err != nil {
		return err
	}
	defer r.Close()

	for _, f := range r.File {
		if err := extractFile(f, dest); err != nil {
			return err
		}
	}
	return nil
}

func extractFile(f *zip.File, dest string) error {
	cleanDest := filepath.Clean(dest)
	target := filepath.Join(cleanDest, f.Name)
	if target != cleanDest && !strings.HasPrefix(target, cleanDest+string(os.PathSeparator)) {
		return fmt.Errorf("illegal file path %q", f.Name)
	}

	if f.FileInfo().IsDir() {
		return os.MkdirAll(target, 0o755)
	}

	if err := os.MkdirAll(filepath.Dir(target), 0o755); err != nil {
		return err
	}

	rc, err := f.Open()
	if err != nil {
		return err
	}
	defer rc.Close()

	out, err := os.OpenFile(target, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
	if err != nil {
		return err
	}
	defer out.Close()

	_, err = io.Copy(out, rc)
	return err
}