<?php

namespace Modules\Stylist\Services;

use Illuminate\Database\QueryException;
use Modules\Stylist\Models\ThemeSetting;
use Modules\Stylist\Theme\Theme;

final class ThemeSettings
{
    private const APPEARANCE_KEY = '__stylist_appearance';

    private const ACCENT_KEY = '__stylist_accent';

    public function get(Theme $theme): array
    {
        $stored = $this->stored($theme);
        $defaults = collect($theme->settingsSchema())
            ->mapWithKeys(fn ($definition, $key) => [$key => is_array($definition) ? ($definition['default'] ?? null) : $definition])
            ->all();

        return array_replace($defaults, array_diff_key((array) ($stored?->settings ?? []), array_flip([self::APPEARANCE_KEY, self::ACCENT_KEY])));
    }

    public function variant(Theme $theme): string
    {
        $variant = (string) ($this->stored($theme)?->variant ?? array_key_first($theme->variants()) ?? 'light');

        return array_key_exists($variant, $theme->variants()) ? $variant : (array_key_first($theme->variants()) ?? 'light');
    }

    public function appearance(Theme $theme): string
    {
        $stored = (array) ($this->stored($theme)?->settings ?? []);
        $allowed = array_keys($theme->appearances());
        if ($allowed === []) {
            return '';
        }
        $appearance = (string) ($stored[self::APPEARANCE_KEY] ?? $theme->defaultAppearance());

        return in_array($appearance, $allowed, true) ? $appearance : (string) array_key_first($theme->appearances());
    }

    public function accent(Theme $theme): string
    {
        $stored = (array) ($this->stored($theme)?->settings ?? []);
        $allowed = array_keys($theme->accents());
        if ($allowed === []) {
            return '';
        }
        $accent = (string) ($stored[self::ACCENT_KEY] ?? $theme->defaultAccent());

        return in_array($accent, $allowed, true) ? $accent : (string) array_key_first($theme->accents());
    }

    public function save(Theme $theme, array $settings, string $variant, ?string $appearance = null, ?string $accent = null): ThemeSetting
    {
        $settings = array_intersect_key($settings, array_flip(array_keys($theme->settingsSchema())));
        $existing = (array) ($this->stored($theme)?->settings ?? []);

        $allowedAppearances = array_keys($theme->appearances());
        if ($allowedAppearances !== []) {
            $appearance ??= (string) ($existing[self::APPEARANCE_KEY] ?? $theme->defaultAppearance());
            if (! in_array($appearance, $allowedAppearances, true)) {
                $appearance = (string) array_key_first($theme->appearances());
            }
            $settings[self::APPEARANCE_KEY] = $appearance;
        }

        $allowedAccents = array_keys($theme->accents());
        if ($allowedAccents !== []) {
            $accent ??= (string) ($existing[self::ACCENT_KEY] ?? $theme->defaultAccent());
            if (! in_array($accent, $allowedAccents, true)) {
                $accent = (string) array_key_first($theme->accents());
            }
            $settings[self::ACCENT_KEY] = $accent;
        }

        if ($theme->variants() && ! array_key_exists($variant, $theme->variants())) {
            $variant = array_key_first($theme->variants());
        }

        return ThemeSetting::query()->updateOrCreate(
            ['theme_key' => $theme->key()],
            ['settings' => $settings, 'variant' => $variant]
        );
    }

    private function stored(Theme $theme): ?ThemeSetting
    {
        try {
            return ThemeSetting::query()->where('theme_key', $theme->key())->first();
        } catch (QueryException) {
            return null;
        }
    }
}