package company

import (
	"fmt"
	"strings"
)

// Well-known tenant company_settings.settings JSON keys (migrator domain fields).
// Do not invent preference keys here — extend only when a real product key exists.
const (
	SettingsKeyLanguage      = "language"
	SettingsKeyMergeProducts = "merge_products"
)

// AllowedSettingsKeys is the allowlist for PUT /api/company/settings mass-assignment guard.
func AllowedSettingsKeys() map[string]struct{} {
	return map[string]struct{}{
		SettingsKeyLanguage:      {},
		SettingsKeyMergeProducts: {},
	}
}

func isAllowedSettingsKey(key string) bool {
	_, ok := AllowedSettingsKeys()[key]
	return ok
}

// ValidateSettingsMap rejects unknown keys and mistyped values for the settings bag.
// nil / empty maps are valid (clear or no-op payload).
func ValidateSettingsMap(settings map[string]any) error {
	if len(settings) == 0 {
		return nil
	}
	for k, v := range settings {
		if strings.TrimSpace(k) == "" || strings.ContainsAny(k, " \t\n\r") || k != strings.TrimSpace(k) {
			return fmt.Errorf("unknown settings key")
		}
		if !isAllowedSettingsKey(k) {
			return fmt.Errorf("unknown settings key")
		}
		switch k {
		case SettingsKeyLanguage:
			raw, ok := v.(string)
			if !ok {
				return fmt.Errorf("invalid language")
			}
			if _, err := ParseLanguage(raw, false); err != nil {
				return fmt.Errorf("unsupported language")
			}
		case SettingsKeyMergeProducts:
			if _, ok := v.(bool); !ok {
				return fmt.Errorf("invalid merge_products")
			}
		}
	}
	return nil
}