import os
import warnings
from collections.abc import Mapping
from apiflask import APIFlask

from iti.applications.common.utils.schema import custom_schema_name_resolver
from iti.applications.service import init_services
from iti.modules import init_modules
from iti.service_client import init_service_clients
from iti.tasks import init_task_runner
from .extensions import init_exts
from .routes import init_routes
from ..config import get_config


def create_app(config_name=None, modules=None, config_mapping=None, model_imports=None):
    """
    应用工厂函数

    Args:
        config_name: 配置名称 ('dev', 'test', 'prod')
                    如果为 None，则从环境变量 FLASK_ENV 读取
        modules: 进程内业务模块列表
        config_mapping: 业务项目配置映射，格式与 iti.config.config 一致
        model_imports: 业务模型导入函数列表。用于让 Flask-Migrate 看到业务模型

    Returns:
        Flask 应用实例

    docs_ui: The UI of API documentation, one of `swagger-ui` (default), `redoc`,
                `elements`, `rapidoc`, and `rapipdf`.
    """
    # 忽略 apispec 的 schema 名称冲突警告
    warnings.filterwarnings(
        "ignore",
        message="Multiple schemas resolved to the name",
        category=UserWarning,
        module="apispec.ext.marshmallow.openapi",
    )

    app = APIFlask(
        __name__.split(".")[0],
        title="iTi-Flask",
        version="1.0.0",
        json_errors=True,
        docs_ui="elements",
    )

    # 加载配置
    config_obj = _resolve_config(config_name, config_mapping)
    app.config.from_object(config_obj)

    # 配置自定义 schema 名称解析器
    # 参考：https://zh.apiflask.com/schema/#%E6%A8%A1%E5%BC%8F%E5%90%8D%E7%A7%B0%E8%A7%A3%E6%9E%90%E5%99%A8
    # 用于解决循环引用和嵌套 schema 导致的命名冲突警告
    app.schema_name_resolver = custom_schema_name_resolver

    # 确保必要的目录存在
    _ensure_directories(app)

    # 注册框架 CLI
    from iti.cli import iti_cli

    app.cli.add_command(iti_cli, "iti")

    # 使用第三方JWT，自定义Security，避免doc无法传递header
    # 等同于 SECURITY_SCHEMES 配置
    app.security_schemes = {
        "JWT": {
            "type": "apiKey",
            "in": "header",
            "name": "Authorization",
        }
    }

    # 保护doc文档（鉴权后才可访问）
    # app.config['SPEC_DECORATORS'] = [jwt_required()]
    # app.config['DOCS_DECORATORS'] = [jwt_required()]

    # 初始化扩展
    init_exts(app)

    # 导入业务模型，确保 Alembic autogenerate 能看到业务表。
    for import_models in model_imports or []:
        import_models()

    # 初始化可配置服务客户端与任务系统
    init_service_clients(app)
    init_task_runner(app)

    # 初始化业务模块。模块路由会在系统路由之后注册。
    module_registry = init_modules(app, modules)

    # 初始化路由
    init_routes(app)

    module_registry.run_phase("register_routes", app)
    module_registry.run_phase("register_permissions", app)
    module_registry.run_phase("register_menu_seed", app)

    # 初始化Services
    init_services(app)

    # 打印当前环境信息
    env = config_name or os.getenv("FLASK_ENV", "dev")
    print(f"🚀 应用启动 - 环境: {env}")
    print(f"📊 数据库: {app.config.get('SQLALCHEMY_DATABASE_URI')}")

    return app


def _resolve_config(config_name=None, config_mapping=None):
    if config_mapping is None:
        return get_config(config_name)

    env_name = config_name or os.getenv("FLASK_ENV", "dev")
    if isinstance(config_mapping, Mapping):
        return config_mapping.get(
            env_name, config_mapping.get("default", get_config(config_name))
        )

    return config_mapping


def _ensure_directories(app):
    """确保必要的目录存在"""
    # 数据库目录（SQLite）
    db_uri = app.config.get("SQLALCHEMY_DATABASE_URI", "")
    if "sqlite:///" in db_uri and not db_uri.endswith(":memory:"):
        db_path = db_uri.replace("sqlite:///", "")
        db_dir = os.path.dirname(db_path)
        if db_dir and not os.path.exists(db_dir):
            os.makedirs(db_dir, exist_ok=True)

    file_storage_config = app.config.get("FILE_STORAGE", {})
    local_config = file_storage_config.get("LOCAL", {})
    local_path = local_config.get("base_path")
    if local_path:
        os.makedirs(local_path, exist_ok=True)