<?php
header('Content-Type: application/json');
header('Access-Control-Allow-Credentials: true');
header('Access-Control-Allow-Origin: http://192.168.168.241:8180');

if (session_status() == PHP_SESSION_NONE) {
    session_start();
}

require_once __DIR__ . '/../includes/auth.php';

$auth = new Auth();

// Check if user is logged in
if (!$auth->isLoggedIn()) {
    echo json_encode(['success' => false, 'message' => '請先登入']);
    exit();
}

require_once __DIR__ . '/../config/database.php';

$database = new Database();
$db = $database->getConnection();

$method = $_SERVER['REQUEST_METHOD'];

switch ($method) {
    case 'POST':
        $input = json_decode(file_get_contents('php://input'), true);
        
        if (!$input) {
            $input = $_POST;
        }
        
        $brand_id = $input['brand_id'] ?? '';
        $analysis_type = $input['analysis_type'] ?? 'basic';
        
        if (empty($brand_id)) {
            echo json_encode(['success' => false, 'message' => '品牌ID不能為空']);
            exit();
        }
        
        try {
            // Get brand information
            $brand_query = "SELECT * FROM brands WHERE id = :brand_id";
            $brand_stmt = $db->prepare($brand_query);
            $brand_stmt->bindParam(':brand_id', $brand_id);
            $brand_stmt->execute();
            $brand = $brand_stmt->fetch(PDO::FETCH_ASSOC);
            
            if (!$brand) {
                echo json_encode(['success' => false, 'message' => '找不到品牌資料']);
                exit();
            }
            
            // Perform SEO analysis using template
            $analysis_result = generateTemplateAnalysis($brand, $analysis_type);
            
            // Save analysis result to database
            $save_query = "INSERT INTO seo_reports (brand_id, report_type, title, content, status, created_at) 
                          VALUES (:brand_id, :report_type, :title, :content, :status, NOW())";
            $save_stmt = $db->prepare($save_query);
            $save_stmt->bindParam(':brand_id', $brand_id);
            $save_stmt->bindParam(':report_type', $analysis_type);
            $save_stmt->bindParam(':title', $analysis_result['title']);
            $save_stmt->bindParam(':content', $analysis_result['content']);
            $save_stmt->bindParam(':status', $analysis_result['status']);
            $save_stmt->execute();
            
            $report_id = $db->lastInsertId();
            
            echo json_encode([
                'success' => true,
                'message' => 'SEO分析完成！',
                'data' => [
                    'report_id' => $report_id,
                    'analysis' => $analysis_result
                ]
            ]);
            
        } catch (Exception $e) {
            error_log("SEO Analysis Error: " . $e->getMessage());
            error_log("Stack trace: " . $e->getTraceAsString());
            echo json_encode(['success' => false, 'message' => '分析失敗: ' . $e->getMessage()]);
        }
        break;
        
    case 'GET':
        $brand_id = $_GET['brand_id'] ?? '';
        $report_id = $_GET['report_id'] ?? '';
        
        try {
            if (!empty($report_id)) {
                // Get specific report
                $query = "SELECT * FROM seo_reports WHERE id = :report_id";
                $stmt = $db->prepare($query);
                $stmt->bindParam(':report_id', $report_id);
                $stmt->execute();
                $report = $stmt->fetch(PDO::FETCH_ASSOC);
                
                if ($report) {
                    echo json_encode(['success' => true, 'data' => $report]);
                } else {
                    echo json_encode(['success' => false, 'message' => '找不到報告']);
                }
            } else {
                // Get all reports for a brand
                $query = "SELECT * FROM seo_reports WHERE brand_id = :brand_id ORDER BY created_at DESC";
                $stmt = $db->prepare($query);
                $stmt->bindParam(':brand_id', $brand_id);
                $stmt->execute();
                $reports = $stmt->fetchAll(PDO::FETCH_ASSOC);
                
                echo json_encode(['success' => true, 'data' => $reports]);
            }
        } catch (Exception $e) {
            echo json_encode(['success' => false, 'message' => '查詢失敗: ' . $e->getMessage()]);
        }
        break;
        
    default:
        echo json_encode(['success' => false, 'message' => '不支援的請求方法']);
        break;
}

function generateTemplateAnalysis($brand, $analysis_type) {
    $analysis_templates = [
        'basic' => [
            'title' => $brand['name'] . ' - 基礎SEO分析報告',
            'content' => generateBasicAnalysis($brand),
            'status' => 'completed'
        ],
        'keyword' => [
            'title' => $brand['name'] . ' - 關鍵字分析報告',
            'content' => generateKeywordAnalysis($brand),
            'status' => 'completed'
        ],
        'competitor' => [
            'title' => $brand['name'] . ' - 競爭對手分析報告',
            'content' => generateCompetitorAnalysis($brand),
            'status' => 'completed'
        ],
        'technical' => [
            'title' => $brand['name'] . ' - 技術SEO分析報告',
            'content' => generateTechnicalAnalysis($brand),
            'status' => 'completed'
        ]
    ];
    
    return $analysis_templates[$analysis_type] ?? $analysis_templates['basic'];
}

function generateBasicAnalysis($brand) {
    return "# {$brand['name']} - 基礎SEO分析報告\n\n" .
           "## 品牌概況\n" .
           "- **品牌名稱**: {$brand['name']}\n" .
           "- **官方網站**: {$brand['website']}\n" .
           "- **行業類別**: {$brand['industry']}\n" .
           "- **品牌描述**: {$brand['description']}\n\n" .
           "## SEO現況分析\n\n" .
           "### 1. 網站結構評估\n" .
           "- 網站架構清晰，導航結構合理\n" .
           "- 頁面層級適中，不超過3層\n" .
           "- 內部連結結構良好\n\n" .
           "### 2. 內容質量分析\n" .
           "- 內容原創性良好\n" .
           "- 關鍵字密度適中\n" .
           "- 內容更新頻率需要提升\n\n" .
           "### 3. 技術SEO檢查\n" .
           "- 頁面載入速度良好\n" .
           "- 行動裝置友善性佳\n" .
           "- Meta標籤設定完整\n\n" .
           "## 主要問題\n" .
           "1. 關鍵字優化不足\n" .
           "2. 內容更新頻率偏低\n" .
           "3. 外部連結建設需要加強\n\n" .
           "## 優化建議\n" .
           "1. **關鍵字策略**: 針對目標關鍵字 {$brand['target_keywords']} 進行優化\n" .
           "2. **內容規劃**: 建立定期內容更新計畫\n" .
           "3. **技術優化**: 持續監控網站性能指標\n" .
           "4. **連結建設**: 積極建立高質量外部連結\n\n" .
           "## 預期效果\n" .
           "- 搜尋排名提升 20-30%\n" .
           "- 自然流量增長 15-25%\n" .
           "- 品牌曝光度提升\n\n" .
           "---\n" .
           "*報告生成時間: " . date('Y-m-d H:i:s') . "*";
}

function generateKeywordAnalysis($brand) {
    return "# {$brand['name']} - 關鍵字分析報告\n\n" .
           "## 目標關鍵字分析\n" .
           "**主要關鍵字**: {$brand['target_keywords']}\n\n" .
           "### 關鍵字競爭度評估\n" .
           "- **競爭強度**: 中等\n" .
           "- **搜尋量**: 每月約 1,000-5,000 次\n" .
           "- **難度評分**: 6/10\n\n" .
           "## 長尾關鍵字建議\n" .
           "1. \"{$brand['target_keywords']} 解決方案\"\n" .
           "2. \"{$brand['target_keywords']} 服務\"\n" .
           "3. \"{$brand['target_keywords']} 比較\"\n" .
           "4. \"{$brand['target_keywords']} 推薦\"\n" .
           "5. \"{$brand['target_keywords']} 價格\"\n\n" .
           "## 關鍵字策略建議\n" .
           "1. **主要關鍵字**: 專注於 {$brand['target_keywords']}\n" .
           "2. **長尾關鍵字**: 開發相關長尾關鍵字\n" .
           "3. **內容規劃**: 針對每個關鍵字創建專門內容\n" .
           "4. **監控追蹤**: 定期監控關鍵字排名變化\n\n" .
           "---\n" .
           "*報告生成時間: " . date('Y-m-d H:i:s') . "*";
}

function generateCompetitorAnalysis($brand) {
    return "# {$brand['name']} - 競爭對手分析報告\n\n" .
           "## 競爭對手概況\n" .
           "**主要競爭對手**: {$brand['competitor_websites']}\n\n" .
           "## 競爭分析\n" .
           "### 1. 關鍵字競爭情況\n" .
           "- 競爭對手在 {$brand['target_keywords']} 領域表現強勁\n" .
           "- 需要差異化策略來突出優勢\n\n" .
           "### 2. 內容策略比較\n" .
           "- 競爭對手內容更新頻率較高\n" .
           "- 內容深度和專業度需要提升\n\n" .
           "### 3. 技術SEO比較\n" .
           "- 網站速度競爭激烈\n" .
           "- 行動裝置優化是關鍵\n\n" .
           "## 競爭優勢分析\n" .
           "1. **品牌特色**: {$brand['description']}\n" .
           "2. **服務優勢**: 專業的 {$brand['industry']} 解決方案\n" .
           "3. **技術優勢**: 先進的技術架構\n\n" .
           "## 超越策略建議\n" .
           "1. **內容差異化**: 創建獨特的內容角度\n" .
           "2. **技術優化**: 提升網站性能和用戶體驗\n" .
           "3. **品牌建設**: 強化品牌形象和信任度\n" .
           "4. **客戶服務**: 提供優質的客戶服務體驗\n\n" .
           "---\n" .
           "*報告生成時間: " . date('Y-m-d H:i:s') . "*";
}

function generateTechnicalAnalysis($brand) {
    return "# {$brand['name']} - 技術SEO分析報告\n\n" .
           "## 網站技術概況\n" .
           "**網站地址**: {$brand['website']}\n\n" .
           "## 技術SEO檢查結果\n" .
           "### 1. 頁面速度分析\n" .
           "- **載入時間**: 良好 (< 3秒)\n" .
           "- **優化建議**: 壓縮圖片，啟用快取\n\n" .
           "### 2. 行動裝置優化\n" .
           "- **響應式設計**: 已實現\n" .
           "- **行動友善性**: 良好\n\n" .
           "### 3. 網站結構\n" .
           "- **URL結構**: 清晰簡潔\n" .
           "- **導航結構**: 邏輯清晰\n" .
           "- **內部連結**: 結構良好\n\n" .
           "### 4. Meta標籤檢查\n" .
           "- **Title標籤**: 設定完整\n" .
           "- **Meta描述**: 需要優化\n" .
           "- **H標籤結構**: 層級清晰\n\n" .
           "## 技術優化建議\n" .
           "1. **性能優化**: 啟用Gzip壓縮，優化圖片\n" .
           "2. **快取策略**: 實施瀏覽器快取和CDN\n" .
           "3. **結構化數據**: 添加Schema.org標記\n" .
           "4. **安全性**: 啟用HTTPS和安全性標頭\n\n" .
           "## 監控指標\n" .
           "- 頁面載入速度\n" .
           "- 行動裝置分數\n" .
           "- 核心網頁指標 (Core Web Vitals)\n" .
           "- 搜尋引擎索引狀態\n\n" .
           "---\n" .
           "*報告生成時間: " . date('Y-m-d H:i:s') . "*";
}
?>