package bootstrap

import (
	"context"
	"errors"
	"fmt"
	"path/filepath"
	"strings"

	"github.com/jackc/pgx/v5"
)

const defaultThemePresetID = "moku-midnight"

func personalSettingsPathForDisplayName(displayName string) string {
	personalName := strings.TrimSpace(displayName)
	if personalName == "" {
		personalName = defaultPersonalDisplayName
	}

	personalSlug := normalizePOSIXSlug(personalName)
	return filepath.ToSlash(filepath.Join("users", "personals", slugDir("personal", personalSlug), posixSettingsFileName))
}

func extractThemePresetID(settings map[string]any) string {
	theme, ok := settings["theme"].(map[string]any)
	if !ok {
		return ""
	}

	presetID, _ := theme["presetId"].(string)
	return strings.TrimSpace(presetID)
}

func applyThemePresetToSettings(settings map[string]any, presetID string) map[string]any {
	normalized := settings
	if normalized == nil {
		normalized = map[string]any{}
	}

	theme, ok := normalized["theme"].(map[string]any)
	if !ok || theme == nil {
		theme = map[string]any{}
	}

	theme["presetId"] = presetID
	normalized["theme"] = theme
	return normalized
}

func (service *Service) SaveThemePreset(ctx context.Context, input SaveThemePresetInput) (*AdminRecord, error) {
	admin, err := service.GetAdmin(ctx)
	if err != nil {
		return nil, err
	}
	if admin == nil {
		return nil, ErrAdminNotConfigured
	}

	presetID := strings.TrimSpace(input.PresetID)
	if presetID == "" {
		return nil, fmt.Errorf("theme preset id is required")
	}

	rootPath := strings.TrimSpace(service.posixRoot)
	if rootPath == "" {
		return nil, fmt.Errorf("posix root is not configured")
	}

	relativeSettingsPath := personalSettingsPathForDisplayName(admin.DisplayName)
	absoluteSettingsPath := filepath.Join(rootPath, filepath.FromSlash(relativeSettingsPath))
	settings := readStructuredFileMap(absoluteSettingsPath)
	if len(settings) == 0 {
		return nil, fmt.Errorf("personal settings file is missing")
	}

	updatedSettings := applyThemePresetToSettings(settings, presetID)
	if err := writeCBORFile(absoluteSettingsPath, updatedSettings); err != nil {
		return nil, fmt.Errorf("write personal %s: %w", posixSettingsFileName, err)
	}

	if err := service.rebuildProjection(ctx); err != nil {
		return nil, err
	}

	return service.GetAdmin(ctx)
}

func (service *Service) loadAdminThemePresetID(ctx context.Context, displayName string) (string, error) {
	path := personalSettingsPathForDisplayName(displayName)

	var presetID *string
	err := service.db.Pool.QueryRow(ctx, `
		SELECT content_json->'theme'->>'presetId'
		FROM posix_nodes
		WHERE path = $1
		LIMIT 1;
	`, path).Scan(&presetID)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return "", nil
		}
		return "", err
	}

	if presetID == nil {
		return "", nil
	}

	return strings.TrimSpace(*presetID), nil
}