package cabana

import (
	"bytes"
	"fmt"
	"io/fs"
	"path"
	"strings"

	"github.com/goccy/go-yaml"
)

func decodeStrict(raw []byte, dest any) error {
	dec := yaml.NewDecoder(bytes.NewReader(raw), yaml.DisallowUnknownField())
	if err := dec.Decode(dest); err != nil {
		return err
	}
	return nil
}

// decodeStrictOrdered is decodeStrict with every nested mapping kept as an
// ordered yaml.MapSlice, so a file that is decoded, re-marshalled per entry and
// decoded again keeps its key order at any depth and any indentation.
func decodeStrictOrdered(raw []byte, dest any) error {
	dec := yaml.NewDecoder(bytes.NewReader(raw), yaml.DisallowUnknownField(), yaml.UseOrderedMap())
	return dec.Decode(dest)
}

func readAsset(fsys fs.FS, name string) ([]byte, error) {
	name = path.Clean(name)
	if name == "." || strings.HasPrefix(name, "..") || strings.Contains(name, "..") {
		return nil, fmt.Errorf("path escapes the plugin")
	}
	return fs.ReadFile(fsys, name)
}

// assetPath resolves a YAML file reference to a path inside the plugin's
// AdminFS: a plugin-relative path, ~/plugins/<vendor>/<plugin>/rest, or
// WinterCMS's $/<vendor>/<plugin>/rest ($/ is the plugins directory). A $/
// path into another plugin cannot be read from this plugin's tree and is an
// error.
func assetPath(pluginID, ref string) (string, error) {
	ref = strings.TrimSpace(ref)
	own := strings.ReplaceAll(pluginID, ".", "/") + "/"
	if rest, ok := strings.CutPrefix(ref, "$/"); ok {
		if !strings.HasPrefix(rest, own) {
			return "", fmt.Errorf("$/ path %s names another plugin", ref)
		}
		ref = strings.TrimPrefix(rest, own)
	}
	ref = strings.TrimPrefix(ref, "~/")
	prefix := "plugins/" + own
	ref = strings.TrimPrefix(ref, prefix)
	ref = path.Clean(ref)
	if ref == "." || strings.HasPrefix(ref, "..") || strings.Contains(ref, "..") {
		return "", fmt.Errorf("list path escapes the plugin")
	}
	return ref, nil
}

func identifier(s string) bool {
	if s == "" {
		return false
	}
	for i, r := range s {
		switch {
		case r >= 'a' && r <= 'z', r >= 'A' && r <= 'Z', r == '_':
		case i > 0 && r >= '0' && r <= '9':
		default:
			return false
		}
	}
	return true
}

func bootErr(pluginID, controllerID, file string, err error) error {
	return fmt.Errorf("cabana: admin schema %s/%s/%s: %w", pluginID, controllerID, file, err)
}