import os
import re
import uuid
import shutil
from datetime import datetime
from flask import Flask, request, jsonify, render_template
from config import (
    NAS_DATA_PATH, PORT, ALLOWED_EXTENSIONS,
    MAX_FILES_COUNT, MAX_FILE_SIZE_MB, ALLOWED_MIME_TYPES
)

app = Flask(__name__)


# ========== 工具函数 ==========

def get_camp_folders():
    """获取所有训练营文件夹列表，按期数排序"""
    if not os.path.exists(NAS_DATA_PATH):
        os.makedirs(NAS_DATA_PATH, exist_ok=True)
        return []

    folders = []
    for name in os.listdir(NAS_DATA_PATH):
        full_path = os.path.join(NAS_DATA_PATH, name)
        if os.path.isdir(full_path) and re.match(r'^训练营\d+期$', name):
            folders.append(name)

    # 按期数数字排序
    folders.sort(key=lambda x: int(re.search(r'\d+', x).group()) if re.search(r'\d+', x) else 0)
    return folders


def get_class_folders(camp_name):
    """获取某个训练营下的所有班级文件夹，按班号排序"""
    camp_path = os.path.join(NAS_DATA_PATH, camp_name)
    if not os.path.exists(camp_path):
        return []

    classes = []
    for name in os.listdir(camp_path):
        full_path = os.path.join(camp_path, name)
        if os.path.isdir(full_path) and re.match(r'^\d+班$', name):
            classes.append(name)

    # 按班号数字排序
    classes.sort(key=lambda x: int(re.search(r'\d+', x).group()) if re.search(r'\d+', x) else 0)
    return classes


def validate_file(file):
    """验证上传文件是否合法，返回 (是否合法, 错误原因)"""
    if not file or not file.filename:
        return False, "空文件"

    # 检查文件大小
    file.seek(0, os.SEEK_END)
    size = file.tell()
    file.seek(0)
    if size > MAX_FILE_SIZE_MB * 1024 * 1024:
        return False, f"文件超过 {MAX_FILE_SIZE_MB}MB 限制"

    if size == 0:
        return False, "空文件"

    # 检查扩展名
    ext = file.filename.rsplit('.', 1)[-1].lower() if '.' in file.filename else ''
    if ext not in ALLOWED_EXTENSIONS:
        return False, f"不支持的格式: {ext}"

    # 检查MIME类型
    mime = file.mimetype
    expected_mime = ALLOWED_MIME_TYPES.get(ext)
    if expected_mime and mime and not mime.startswith(expected_mime.split('/')[0]):
        return False, f"MIME类型不匹配: {mime}"

    return True, None


def generate_filename(original_name, camp_name, class_name):
    """生成新文件名：训练营{n}期-{x}班-{时间戳}-{随机数}.{扩展名}"""
    camp_match = re.search(r'(\d+)', camp_name)
    class_match = re.search(r'(\d+)', class_name)
    camp_num = camp_match.group(1) if camp_match else '?'
    class_num = class_match.group(1) if class_match else '?'

    now = datetime.now()
    timestamp = now.strftime('%Y%m%d%H%M%S')
    random_str = uuid.uuid4().hex[:6]
    ext = original_name.rsplit('.', 1)[-1].lower() if '.' in original_name else 'jpg'

    return f"训练营{camp_num}期-{class_num}班-{timestamp}-{random_str}.{ext}"


def get_unique_filepath(dir_path, filename):
    """获取不冲突的文件路径，若存在则追加序号"""
    filepath = os.path.join(dir_path, filename)
    if not os.path.exists(filepath):
        return filepath

    # 分离文件名和扩展名
    name, ext = os.path.splitext(filename)
    counter = 1
    while True:
        new_name = f"{name}-{counter}{ext}"
        new_path = os.path.join(dir_path, new_name)
        if not os.path.exists(new_path):
            return new_path
        counter += 1


def ensure_folders(camp_name, class_name):
    """确保训练营和班级文件夹存在，不存在则创建"""
    camp_path = os.path.join(NAS_DATA_PATH, camp_name)
    class_path = os.path.join(camp_path, class_name)
    stat_file = os.path.join(camp_path, '统计.md')

    created_camp = False
    if not os.path.exists(camp_path):
        os.makedirs(camp_path, exist_ok=True)
        created_camp = True

    if not os.path.exists(class_path):
        os.makedirs(class_path, exist_ok=True)

    # 如果训练营是新创建的，初始化统计文件
    if created_camp and not os.path.exists(stat_file):
        update_statistics(camp_name)

    return camp_path, class_path


def update_statistics(camp_name):
    """更新某个训练营的统计.md文件"""
    camp_path = os.path.join(NAS_DATA_PATH, camp_name)
    stat_file = os.path.join(camp_path, '统计.md')

    if not os.path.exists(camp_path):
        return

    # 扫描所有班级文件夹
    class_stats = []
    total = 0

    for name in os.listdir(camp_path):
        full_path = os.path.join(camp_path, name)
        if not os.path.isdir(full_path):
            continue
        if not re.match(r'^\d+班$', name):
            continue

        # 统计该班级下的图片数量
        count = 0
        for fname in os.listdir(full_path):
            fpath = os.path.join(full_path, fname)
            if os.path.isfile(fpath):
                ext = fname.rsplit('.', 1)[-1].lower() if '.' in fname else ''
                if ext in ALLOWED_EXTENSIONS:
                    count += 1

        class_stats.append((name, count))
        total += count

    # 按班号排序
    class_stats.sort(key=lambda x: int(re.search(r'\d+', x[0]).group()) if re.search(r'\d+', x[0]) else 0)

    # 写入统计文件
    now = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    lines = [
        f"# {camp_name} 图片统计",
        "",
        f"更新时间：{now}",
        f"图片总数：{total}",
        "",
        "| 班级 | 图片数量 |",
        "|------|----------|",
    ]
    for class_name, count in class_stats:
        lines.append(f"| {class_name}  | {count}       |")

    with open(stat_file, 'w', encoding='utf-8') as f:
        f.write('\n'.join(lines) + '\n')


# ========== 页面路由 ==========

@app.route('/')
def index():
    return render_template('index.html')


# ========== API 路由 ==========

@app.route('/api/folders', methods=['GET'])
def api_folders():
    """获取所有训练营及其下的班级文件夹"""
    folders = []
    for camp_name in get_camp_folders():
        classes = get_class_folders(camp_name)
        folders.append({
            'name': camp_name,
            'classes': classes,
        })
    return jsonify({'folders': folders})


@app.route('/api/upload', methods=['POST'])
def api_upload():
    """上传图片"""
    camp_name = request.form.get('folder', '').strip()
    class_name = request.form.get('class', '').strip()
    files = request.files.getlist('files')

    # 参数校验
    if not camp_name or not re.match(r'^训练营\d+期$', camp_name):
        return jsonify({'success': False, 'error': '无效的训练营名称'}), 400

    if not class_name or not re.match(r'^\d+班$', class_name):
        return jsonify({'success': False, 'error': '无效的班级名称'}), 400

    if not files:
        return jsonify({'success': False, 'error': '未选择文件'}), 400

    if len(files) > MAX_FILES_COUNT:
        return jsonify({'success': False, 'error': f'单次最多上传 {MAX_FILES_COUNT} 张'}), 400

    # 确保文件夹存在
    camp_path, class_path = ensure_folders(camp_name, class_name)

    # 逐个处理文件
    uploaded = []
    failed = []
    has_new_upload = False

    for file in files:
        # 验证文件
        valid, reason = validate_file(file)
        if not valid:
            failed.append({
                'filename': file.filename if file.filename else '未知文件',
                'status': 'failed',
                'reason': reason,
            })
            continue

        # 生成文件名并保存
        new_filename = generate_filename(file.filename, camp_name, class_name)
        filepath = get_unique_filepath(class_path, new_filename)

        try:
            file.save(filepath)
            uploaded.append({
                'filename': os.path.basename(filepath),
                'status': 'success',
            })
            has_new_upload = True
        except Exception as e:
            failed.append({
                'filename': file.filename,
                'status': 'failed',
                'reason': str(e),
            })

    # 如果有新文件上传成功，更新统计
    if has_new_upload:
        try:
            update_statistics(camp_name)
        except Exception:
            pass  # 统计更新失败不影响上传结果

    return jsonify({
        'success': len(uploaded) > 0,
        'uploaded': uploaded,
        'failed': failed,
    })


# ========== 启动 ==========

if __name__ == '__main__':
    # 确保存储目录存在
    if not os.path.exists(NAS_DATA_PATH):
        os.makedirs(NAS_DATA_PATH, exist_ok=True)
        print(f"已创建存储目录: {NAS_DATA_PATH}")

    print(f"服务启动在 http://0.0.0.0:{PORT}")
    app.run(host='0.0.0.0', port=PORT, debug=False)