// Path: Backend/internal/bootstrap/project_disk_helpers.go

package bootstrap

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"unicode"

	"github.com/fxamacker/cbor/v2"
	"github.com/tailscale/hujson"
)

const (
	posixSettingsFileName = "settings.cbor"
	posixLayoutFileName   = "layout.cbor"
	posixHomeFileName     = "home.cbor"
	posixUsersFileName    = "users.cbor"
	posixACLFileName      = "acl.cbor"
	posixFolderFileName   = "folder.cbor"
	posixItemFileName     = "item.cbor"
	posixDataFileName     = "data.cbor"
	posixSchemaFileName   = "schema.json"
	posixManifestFileName = "manifest.jsonc"
)

func samePath(left, right string) bool {
	cleanLeft := filepath.Clean(left)
	cleanRight := filepath.Clean(right)
	if cleanLeft == cleanRight {
		return true
	}
	leftInfo, leftErr := os.Stat(cleanLeft)
	rightInfo, rightErr := os.Stat(cleanRight)
	if leftErr == nil && rightErr == nil {
		return os.SameFile(leftInfo, rightInfo)
	}
	return false
}

func normalizePOSIXSlug(value string) string {
	trimmed := strings.TrimSpace(strings.ToLower(value))
	if trimmed == "" {
		return "untitled"
	}
	var builder strings.Builder
	lastDash := false
	for _, r := range trimmed {
		switch {
		case unicode.IsLetter(r) || unicode.IsDigit(r):
			builder.WriteRune(r)
			lastDash = false
		case r == '-' || r == '_' || unicode.IsSpace(r):
			if !lastDash && builder.Len() > 0 {
				builder.WriteByte('-')
				lastDash = true
			}
		}
	}
	slug := strings.Trim(builder.String(), "-")
	if slug == "" {
		return "untitled"
	}
	return slug
}

func fallbackFolderLabel(path string) string {
	base := filepath.Base(filepath.FromSlash(path))
	trimmed := strings.TrimPrefix(base, "folder-")
	parts := strings.FieldsFunc(trimmed, func(r rune) bool { return r == '-' || r == '_' })
	for index, part := range parts {
		if part != "" {
			parts[index] = strings.ToUpper(part[:1]) + part[1:]
		}
	}
	label := strings.Join(parts, " ")
	if label == "" {
		return base
	}
	return label
}

func fallbackItemLabel(path string) string {
	base := filepath.Base(filepath.FromSlash(path))
	trimmed := strings.TrimPrefix(base, "item-")
	parts := strings.FieldsFunc(trimmed, func(r rune) bool { return r == '-' || r == '_' })
	for index, part := range parts {
		if part != "" {
			parts[index] = strings.ToUpper(part[:1]) + part[1:]
		}
	}
	label := strings.Join(parts, " ")
	if label == "" {
		return base
	}
	return label
}

func normalizeProjectTreeItemType(itemType string) string {
	switch strings.TrimSpace(strings.ToLower(itemType)) {
	case "", "board", "core.board", "core.board.kanban", "kanban":
		return "core.board.kanban"
	case "core.doc", "doc", "document":
		return "core.doc"
	case "core.board.list", "list", "list-board":
		return "core.board.list"
	default:
		return strings.TrimSpace(itemType)
	}
}

func defaultProjectTreeItemSchema(itemType string) map[string]any {
	return map[string]any{"type": "object", "itemType": normalizeProjectTreeItemType(itemType)}
}

func defaultProjectTreeItemData(itemType, name string) map[string]any {
	return map[string]any{"title": strings.TrimSpace(name), "itemType": normalizeProjectTreeItemType(itemType)}
}

func slugDir(prefix, slug string) string {
	trimmedSlug := strings.TrimSpace(slug)
	if trimmedSlug == "" {
		return prefix
	}
	return fmt.Sprintf("%s-%s", prefix, trimmedSlug)
}

func writeJSONFile(path string, payload any) error {
	parentDir := filepath.Dir(path)
	if err := os.MkdirAll(parentDir, 0o755); err != nil {
		return err
	}
	data, err := json.MarshalIndent(payload, "", "  ")
	if err != nil {
		return err
	}
	data = append(data, '\n')
	return os.WriteFile(path, data, 0o644)
}

func writeJSONCFile(path string, payload any) error {
	parentDir := filepath.Dir(path)
	if err := os.MkdirAll(parentDir, 0o755); err != nil {
		return err
	}
	data, err := json.MarshalIndent(payload, "", "  ")
	if err != nil {
		return err
	}
	content := append([]byte("// This file is JSONC. Comments and trailing commas are allowed.\n"), data...)
	content = append(content, '\n')
	return os.WriteFile(path, content, 0o644)
}

func writeCBORFile(path string, payload any) error {
	parentDir := filepath.Dir(path)
	if err := os.MkdirAll(parentDir, 0o755); err != nil {
		return err
	}
	data, err := cbor.Marshal(payload)
	if err != nil {
		return err
	}
	return os.WriteFile(path, data, 0o644)
}

func readStructuredFileMap(path string) map[string]any {
	data, err := os.ReadFile(path)
	if err != nil {
		return map[string]any{}
	}
	var payload any
	switch strings.ToLower(filepath.Ext(path)) {
	case ".cbor":
		err = cbor.Unmarshal(data, &payload)
	case ".json":
		err = json.Unmarshal(data, &payload)
	case ".jsonc":
		payload, err = decodeJSONCToAny(data)
	default:
		return map[string]any{}
	}
	if err != nil || payload == nil {
		return map[string]any{}
	}
	normalized, ok := normalizeStructuredValue(payload).(map[string]any)
	if !ok || normalized == nil {
		return map[string]any{}
	}
	return normalized
}

func decodeJSONCToAny(data []byte) (any, error) {
	ast, err := hujson.Parse(data)
	if err != nil {
		return nil, err
	}
	ast.Standardize()
	standardized := ast.Pack()
	var payload any
	if err := json.Unmarshal(standardized, &payload); err != nil {
		return nil, err
	}
	return payload, nil
}

func normalizeStructuredValue(value any) any {
	switch typed := value.(type) {
	case map[string]any:
		normalized := make(map[string]any, len(typed))
		for key, child := range typed {
			normalized[key] = normalizeStructuredValue(child)
		}
		return normalized
	case map[any]any:
		normalized := make(map[string]any, len(typed))
		for key, child := range typed {
			normalized[fmt.Sprint(key)] = normalizeStructuredValue(child)
		}
		return normalized
	case []any:
		normalized := make([]any, len(typed))
		for index, child := range typed {
			normalized[index] = normalizeStructuredValue(child)
		}
		return normalized
	default:
		return value
	}
}