<?php
require_once 'config.php';
require_once __DIR__ . '/error_config.php';
session_start();
set_json_headers();

$method = $_SERVER['REQUEST_METHOD'];

// =====================================================
// 헬퍼: images 배열 정규화
// =====================================================
function normalize_images($input) {
    if (isset($input['images']) && is_array($input['images'])) {
        $images = array_values(array_filter(
            array_map('trim', $input['images']),
            fn($v) => $v !== ''
        ));
        return $images;
    }
    if (isset($input['image']) && trim($input['image']) !== '') {
        return [trim($input['image'])];
    }
    return [];
}

function normalize_stack($input) {
    if (isset($input['stack']) && is_array($input['stack'])) {
        return array_values(array_filter(
            array_map('trim', $input['stack']),
            fn($v) => $v !== ''
        ));
    }
    if (isset($input['stack']) && is_string($input['stack'])) {
        return array_values(array_filter(
            array_map('trim', explode(',', $input['stack'])),
            fn($v) => $v !== ''
        ));
    }
    return [];
}

// 기존 프로젝트 데이터를 새 형식으로 마이그레이션
function migrate_project_data($project) {
    if (!isset($project['images']) || !is_array($project['images'])) {
        $project['images'] = [];
        if (!empty($project['image'])) {
            $project['images'][] = $project['image'];
        }
    }
    $project['image'] = $project['images'][0] ?? '';
    
    // 새 필드들 기본값
    if (!isset($project['stack']) || !is_array($project['stack'])) $project['stack'] = [];
    if (!isset($project['period_start'])) $project['period_start'] = '';
    if (!isset($project['period_end'])) $project['period_end'] = '';
    if (!isset($project['video_url'])) $project['video_url'] = '';
    
    // 기존 demo_url 필드는 제거 (마이그레이션)
    unset($project['demo_url']);
    
    return $project;
}

// =====================================================
// GET: 프로젝트 목록 조회
// =====================================================
if ($method === 'GET') {
    $projects = read_json_safe(PROJECTS_FILE);
    if ($projects === null) {
        json_response(['error' => '데이터를 읽을 수 없습니다'], 500);
    }
    
    $projects = array_map('migrate_project_data', $projects);
    
    usort($projects, function($a, $b) {
        return ($b['id'] ?? 0) - ($a['id'] ?? 0);
    });
    
    json_response($projects);
}

require_auth();

// =====================================================
// POST: 새 프로젝트 추가
// =====================================================
if ($method === 'POST') {
    $input = get_json_input();
    
    $title = trim($input['title'] ?? '');
    $label = trim($input['label'] ?? '');
    $description = trim($input['description'] ?? '');
    
    if (empty($title) || empty($label) || empty($description)) {
        json_response(['error' => '제목, 라벨, 설명은 필수입니다'], 400);
    }
    
    $projects = read_json_safe(PROJECTS_FILE) ?? [];
    
    $maxId = 0;
    foreach ($projects as $p) {
        if (($p['id'] ?? 0) > $maxId) $maxId = $p['id'];
    }
    
    $images = normalize_images($input);
    $stack = normalize_stack($input);
    
    $newProject = [
        'id' => $maxId + 1,
        'title' => $title,
        'label' => $label,
        'description' => $description,
        'icon' => trim($input['icon'] ?? 'fa-solid fa-code'),
        'images' => $images,
        'image' => $images[0] ?? '',
        'link' => trim($input['link'] ?? ''),
        'stack' => $stack,
        'period_start' => trim($input['period_start'] ?? ''),
        'period_end' => trim($input['period_end'] ?? ''),
        'video_url' => trim($input['video_url'] ?? ''),
        'created_at' => date('Y-m-d')
    ];
    
    $projects[] = $newProject;
    
    if (write_json_safe(PROJECTS_FILE, $projects)) {
        json_response(['success' => true, 'project' => $newProject]);
    } else {
        json_response(['error' => '저장에 실패했습니다'], 500);
    }
}

// =====================================================
// PUT: 프로젝트 수정
// =====================================================
if ($method === 'PUT') {
    $input = get_json_input();
    $id = intval($input['id'] ?? 0);
    
    if ($id <= 0) {
        json_response(['error' => '유효하지 않은 ID'], 400);
    }
    
    $projects = read_json_safe(PROJECTS_FILE) ?? [];
    $found = false;
    
    foreach ($projects as $key => $project) {
        if ($project['id'] === $id) {
            $projects[$key]['title'] = trim($input['title'] ?? $project['title']);
            $projects[$key]['label'] = trim($input['label'] ?? $project['label']);
            $projects[$key]['description'] = trim($input['description'] ?? $project['description']);
            $projects[$key]['icon'] = trim($input['icon'] ?? $project['icon']);
            $projects[$key]['link'] = trim($input['link'] ?? $project['link']);
            
            if (isset($input['images']) || isset($input['image'])) {
                $images = normalize_images($input);
                $projects[$key]['images'] = $images;
                $projects[$key]['image'] = $images[0] ?? '';
            }
            
            if (isset($input['stack'])) {
                $projects[$key]['stack'] = normalize_stack($input);
            }
            
            if (isset($input['period_start'])) {
                $projects[$key]['period_start'] = trim($input['period_start']);
            }
            if (isset($input['period_end'])) {
                $projects[$key]['period_end'] = trim($input['period_end']);
            }
            if (isset($input['video_url'])) {
                $projects[$key]['video_url'] = trim($input['video_url']);
            }
            
            // 기존 demo_url 필드 제거
            unset($projects[$key]['demo_url']);
            
            $projects[$key]['updated_at'] = date('Y-m-d');
            $found = true;
            break;
        }
    }
    
    if (!$found) {
        json_response(['error' => '프로젝트를 찾을 수 없습니다'], 404);
    }
    
    if (write_json_safe(PROJECTS_FILE, $projects)) {
        json_response(['success' => true]);
    } else {
        json_response(['error' => '저장에 실패했습니다'], 500);
    }
}

// =====================================================
// DELETE: 프로젝트 삭제
// =====================================================
if ($method === 'DELETE') {
    $id = intval($_GET['id'] ?? 0);
    
    if ($id <= 0) {
        json_response(['error' => '유효하지 않은 ID'], 400);
    }
    
    $projects = read_json_safe(PROJECTS_FILE) ?? [];
    $filtered = array_values(array_filter($projects, function($p) use ($id) {
        return ($p['id'] ?? 0) !== $id;
    }));
    
    if (count($filtered) === count($projects)) {
        json_response(['error' => '프로젝트를 찾을 수 없습니다'], 404);
    }
    
    if (write_json_safe(PROJECTS_FILE, $filtered)) {
        json_response(['success' => true]);
    } else {
        json_response(['error' => '삭제에 실패했습니다'], 500);
    }
}

json_response(['error' => 'Method not allowed'], 405);