import csv
import os
import sys
from pathlib import Path


def init_django():
    base_dir = Path(__file__).resolve().parent
    project_root = base_dir / "ZeroCodeProject" / "apis" / "ZeroCodeMain"
    if not project_root.exists():
        return None
    sys.path.insert(0, str(project_root))
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "ZeroCodeMain.settings")
    try:
        import django

        django.setup()
        from django.db import connection
        from BaseApi.models import App, Model, ModelField, ModelSetting
    except Exception:
        return None
    return App, Model, ModelField, ModelSetting, connection


def export_meta_tables(output_dir: str = None) -> None:
    base_dir = Path(__file__).resolve().parent
    if output_dir is None:
        output_path = base_dir
    else:
        output_path = Path(output_dir)
    output_path.mkdir(parents=True, exist_ok=True)

    all_rows = []

    table1 = [
        ["类名", "所在层/文件", "关键字段", "含义"],
        ["App", "BaseApi/models.py", "name, name_cn, module", "定义动态模型所属的应用和模块路径"],
        ["Model", "BaseApi/models.py", "app, name, name_cn", "定义单个动态模型的元数据（名称及所属应用）"],
        ["ModelField", "BaseApi/models.py", "model, name, type, is_show", "定义动态模型中的单个字段及其类型、显示属性"],
        ["ModelSetting", "BaseApi/models.py", "field, name, value", "定义字段的具体配置项（例如 max_length、null 等）"],
    ]

    all_rows.append(["# 元数据类汇总表"])
    all_rows.extend(table1)
    all_rows.append([])

    table2 = [
        ["元数据实体", "标识字段", "对应的原对象实体", "关系说明"],
        ["App 记录", "name", "Django 应用（AppConfig）", "确定动态模型注册的命名空间及表名前缀"],
        ["Model 记录", "app + name", "动态 Django 模型类 + 物理数据表", "每条 Model 记录对应一个模型类及一张数据表"],
        ["ModelField 记录", "model + name", "动态模型上的一个字段", "每条记录对应模型上的一个具体字段"],
        ["ModelSetting 记录", "field + name", "字段构造器上的一个关键字参数", "决定字段的单个具体属性（如 max_length、null 等）"],
    ]

    all_rows.append(["# 元数据与原对象映射（概念层面）"])
    all_rows.extend(table2)
    all_rows.append([])

    django_models = init_django()
    if not django_models:
        all_file = output_path / "meta_all_in_one.csv"
        with all_file.open("w", newline="", encoding="utf-8-sig") as f:
            writer = csv.writer(f)
            writer.writerows(all_rows)
        return

    App, Model, ModelField, ModelSetting, connection = django_models

    model_rows = [
        [
            "app_name",
            "app_name_cn",
            "app_module",
            "model_name",
            "model_name_cn",
            "django_app_label",
            "django_model_class",
            "db_table_name",
        ]
    ]

    for m in Model.objects.select_related("app").all():
        app = m.app
        django_app_label = app.name
        django_model_class = django_app_label + "." + m.name
        db_table_name = django_app_label + "_" + m.name
        model_rows.append(
            [
                app.name,
                app.name_cn,
                app.module,
                m.name,
                m.name_cn,
                django_app_label,
                django_model_class,
                db_table_name,
            ]
        )

    all_rows.append(["# 元数据模型与原对象模型一对一映射（实例层面）"])
    all_rows.extend(model_rows)
    all_rows.append([])

    settings_map = {}
    for s in ModelSetting.objects.select_related("field").all():
        field_id = s.field_id
        pair = s.name + "=" + s.value
        settings_map.setdefault(field_id, []).append(pair)

    field_rows = [
        [
            "app_name",
            "model_name",
            "field_name",
            "field_name_cn",
            "field_type",
            "is_show",
            "settings",
        ]
    ]

    for f_obj in ModelField.objects.select_related("model", "model__app").all():
        app = f_obj.model.app
        model = f_obj.model
        merged_settings = ";".join(settings_map.get(f_obj.id, []))
        field_rows.append(
            [
                app.name,
                model.name,
                f_obj.name,
                f_obj.name_cn,
                f_obj.type,
                "1" if f_obj.is_show else "0",
                merged_settings,
            ]
        )

    all_rows.append(["# 字段级元数据与原对象字段映射（字段层面）"])
    all_rows.extend(field_rows)
    all_rows.append([])

    table_rows = [["table_name", "model_class", "column_count"]]
    model_map = {
        "BaseApi_app": App,
        "BaseApi_model": Model,
        "BaseApi_modelfield": ModelField,
        "BaseApi_modelsetting": ModelSetting,
    }
    for table_name, model_cls in model_map.items():
        meta = model_cls._meta
        concrete_fields = [f for f in meta.get_fields() if getattr(f, "concrete", False) and not getattr(f, "many_to_many", False)]
        table_rows.append(
            [
                meta.db_table,
                meta.label,
                str(len(concrete_fields)),
            ]
        )

    all_rows.append(["# 元数据相关数据库表结构总览"])
    all_rows.extend(table_rows)
    all_rows.append([])

    column_rows = [
        ["table_name", "model_class", "column_name", "field_type", "null", "primary_key", "default"]
    ]
    for model_cls in [App, Model, ModelField, ModelSetting]:
        meta = model_cls._meta
        for field in meta.get_fields():
            if not getattr(field, "concrete", False) or getattr(field, "many_to_many", False):
                continue
            default_value = field.default
            if callable(default_value):
                default_value = ""
            column_rows.append(
                [
                    meta.db_table,
                    meta.label,
                    field.name,
                    field.get_internal_type(),
                    "1" if field.null else "0",
                    "1" if field.primary_key else "0",
                    str(default_value),
                ]
            )

    all_rows.append(["# 元数据相关数据库字段结构明细"])
    all_rows.extend(column_rows)
    all_rows.append([])

    for model_cls, section_title in [
        (App, "# BaseApi_app 表数据"),
        (Model, "# BaseApi_model 表数据"),
        (ModelField, "# BaseApi_modelfield 表数据"),
        (ModelSetting, "# BaseApi_modelsetting 表数据"),
    ]:
        meta = model_cls._meta
        field_names = [f.name for f in meta.fields]
        rows = [field_names]
        qs = model_cls.objects.all().values_list(*field_names)
        for row in qs:
            rows.append([str(v) for v in row])
        all_rows.append([section_title])
        all_rows.extend(rows)
        all_rows.append([])

    all_file = output_path / "meta_all_in_one.csv"
    with all_file.open("w", newline="", encoding="utf-8-sig") as f:
        writer = csv.writer(f)
        writer.writerows(all_rows)


if __name__ == "__main__":
    export_meta_tables()