<?php

/**
 * Branding helpers — themes, colors, logos, favicons.
 *
 * Extracted from app.php to keep visual-identity concerns in one place.
 */

/**
 * Load configured themes with a safe fallback list.
 */
function appThemes(): array
{
    if (!class_exists('MintyPHP\\Service\\Settings\\ThemeConfigGateway')) {
        return [
            'light' => 'Light',
            'dark' => 'Dark',
        ];
    }

    return app(\MintyPHP\Service\Settings\ThemeConfigGateway::class)->all();
}

/**
 * Resolve default theme from settings, then APP_THEME, then light.
 */
function appDefaultTheme(): string
{
    $themes = appThemes();
    $tenantTheme = strtolower(trim((string) ($_SESSION['current_tenant']['default_theme'] ?? '')));
    if ($tenantTheme !== '' && isset($themes[$tenantTheme])) {
        return $tenantTheme;
    }
    $setting = appSetting('app_theme');
    if ($setting !== null && isset($themes[$setting])) {
        return $setting;
    }
    $envTheme = getenv('APP_THEME') ?: 'light';
    $envTheme = strtolower(trim((string) $envTheme));
    return isset($themes[$envTheme]) ? $envTheme : 'light';
}

/**
 * Resolve effective theme with optional per-user override.
 */
function currentTheme(): string
{
    $themes = appThemes();
    $theme = appDefaultTheme();
    if (!allowUserTheme()) {
        return $theme;
    }
    $user = $_SESSION['user'] ?? [];
    $userTheme = strtolower(trim((string) ($user['theme'] ?? '')));
    if ($userTheme !== '' && isset($themes[$userTheme])) {
        return $userTheme;
    }
    return $theme;
}

/**
 * Resolve active primary color (tenant override -> app setting).
 */
function appPrimaryColor(): ?string
{
    // Tenant-scoped branding has precedence over global settings.
    $tenantColor = $_SESSION['current_tenant']['primary_color'] ?? null;
    if ($tenantColor !== null) {
        $tenantColor = strtolower(trim((string) $tenantColor));
        if (preg_match('/^#([0-9a-f]{3}|[0-9a-f]{6})$/i', $tenantColor)) {
            return $tenantColor;
        }
    }

    $value = appSetting('app_primary_color');
    if ($value === null) {
        return null;
    }
    $value = strtolower(trim($value));
    if (!preg_match('/^#([0-9a-f]{3}|[0-9a-f]{6})$/i', $value)) {
        return null;
    }
    return $value;
}

/**
 * Convert current hex color to CSS HSL custom properties.
 */
function appPrimaryCssVars(): string
{
    $hex = appPrimaryColor();
    if ($hex === null) {
        return '';
    }
    $hex = ltrim($hex, '#');
    if (strlen($hex) === 3) {
        $hex = $hex[0] . $hex[0] . $hex[1] . $hex[1] . $hex[2] . $hex[2];
    }
    $r = hexdec(substr($hex, 0, 2)) / 255;
    $g = hexdec(substr($hex, 2, 2)) / 255;
    $b = hexdec(substr($hex, 4, 2)) / 255;

    // Short-circuit grayscale values to avoid unstable hue math.
    $monoThreshold = 0.000001;
    if (abs($r - $g) < $monoThreshold && abs($g - $b) < $monoThreshold) {
        $l = round($r * 100, 2) . '%';
        return "--app-primary-h-base: 0; --app-primary-s-base: 0%; --app-primary-l-base: {$l}; --app-primary-h-light: 0; --app-primary-s-light: 0%; --app-primary-l-light: {$l};";
    }

    $max = max($r, $g, $b);
    $min = min($r, $g, $b);
    $delta = $max - $min;

    if ($delta === 0.0) {
        $l = round((($max + $min) / 2) * 100, 2) . '%';
        return "--app-primary-h-base: 0; --app-primary-s-base: 0%; --app-primary-l-base: {$l}; --app-primary-h-light: 0; --app-primary-s-light: 0%; --app-primary-l-light: {$l};";
    }

    $h = 0.0;
    if ($max === $r) {
        $h = 60 * fmod((($g - $b) / $delta), 6);
    } elseif ($max === $g) {
        $h = 60 * ((($b - $r) / $delta) + 2);
    } else {
        $h = 60 * ((($r - $g) / $delta) + 4);
    }
    if ($h < 0) {
        $h += 360;
    }

    $l = ($max + $min) / 2;
    $denominator = 1 - abs(2 * $l - 1);
    if ($delta === 0.0 || $denominator === 0.0) {
        $s = 0.0;
    } else {
        $s = $delta / $denominator;
    }

    $h = round($h, 2);
    $s = round($s * 100, 2) . '%';
    $l = round($l * 100, 2) . '%';

    return "--app-primary-h-base: {$h}; --app-primary-s-base: {$s}; --app-primary-l-base: {$l}; --app-primary-h-light: {$h}; --app-primary-s-light: {$s}; --app-primary-l-light: {$l};";
}

/**
 * Resolve app logo path (custom upload with fallback asset).
 */
function appLogoUrl(?int $size = null): string
{
    if (class_exists('MintyPHP\\Service\\Branding\\BrandingLogoService')) {
        $logoService = app(\MintyPHP\Service\Branding\BrandingLogoService::class);
        if ($logoService->hasLogo()) {
            $query = $size ? '?size=' . (int) $size : '';
            return lurl('branding/logo' . $query);
        }
    }
    return asset('brand/logo.svg');
}

/**
 * Resolve logo for auth pages: tenant avatar -> global logo -> default SVG.
 *
 * After logout the tenant context (`$_SESSION['current_tenant']`) is preserved,
 * so the login page can show the tenant avatar instead of the generic app logo.
 */
function appAuthLogoUrl(?int $size = null): string
{
    $tenantUuid = $_SESSION['current_tenant']['uuid'] ?? '';
    if ($tenantUuid !== '' && class_exists('MintyPHP\\Service\\Tenant\\TenantAvatarService')) {
        if (app(\MintyPHP\Service\Tenant\TenantAvatarService::class)->hasAvatar($tenantUuid)) {
            $query = $size ? '&size=' . (int) $size : '';
            return lurl('auth/tenant-avatar-file?uuid=' . rawurlencode($tenantUuid) . $query);
        }
    }
    return appLogoUrl($size);
}

/**
 * Absolute logo URL (used in e-mails and metadata).
 */
function appLogoUrlAbsolute(int $size = 128): string
{
    $url = appLogoUrl($size);
    return appUrl($url);
}

/**
 * Resolve favicon path (tenant favicon with global fallback).
 */
function appFaviconUrl(string $file): string
{
    $tenantUuid = $_SESSION['current_tenant']['uuid'] ?? '';
    if ($tenantUuid !== '' && class_exists('MintyPHP\\Service\\Tenant\\TenantFaviconService')) {
        if (app(\MintyPHP\Service\Tenant\TenantFaviconService::class)->hasFavicon($tenantUuid)) {
            return asset('favicon/tenants/' . $tenantUuid . '/favicon/' . ltrim($file, '/'));
        }
    }
    return asset('favicon/' . ltrim($file, '/'));
}