# -*- coding: utf-8 -*-
"""
pbl_common.tables —— 公共表 DDL（mariadb 方言）

契约（docs/01-design/data-model.md + projects/pbls/env/test.json ddl 段）：
  - 方言 mariadb：主键 `id BIGINT NOT NULL AUTO_INCREMENT`
  - 禁止 FOREIGN KEY / REFERENCES / ENUM / TIMESTAMP
  - 时间列一律 DATETIME
  - 每表首列必须 tenant_id varchar(64) NOT NULL，且索引以 tenant_id 打头
  - 编码列 varchar(32)
  - ENGINE=InnoDB DEFAULT CHARSET=utf8mb4

本模块只声明 pbl_common 自有表（审计 + 幂等种子记录）；
业务表 DDL 在各模块 tables.py 与 apps/pbls/scripts/ddl/pbls_tables.sql。
"""

from pbl_common.errors import DbError

DIALECT = 'mariadb'

# 禁用元素（ensure_tables 前自检，命中即抛错，防方言漂移）
FORBIDDEN_TOKENS = ('FOREIGN KEY', 'REFERENCES ', 'ENUM(', 'TIMESTAMP', 'BIGSERIAL', 'SERIAL', 'nextval')

TABLES = {
    'pbl_audit_log': {
        'comment': 'PBL 审计日志（append-only，审计独立性）',
        'columns': [
            ('tenant_id', "varchar(64) NOT NULL COMMENT '租户ID（强制打头）'"),
            ('action', "varchar(32) NOT NULL COMMENT '动作（白名单 AUDIT_ACTIONS）'"),
            ('action_raw', "varchar(64) DEFAULT NULL COMMENT '原始动作名（未登记动作留痕）'"),
            ('resource_type', "varchar(64) DEFAULT NULL COMMENT '资源类型（表名）'"),
            ('resource_id', "varchar(64) DEFAULT NULL COMMENT '资源主键'"),
            ('user_id', "varchar(64) DEFAULT NULL COMMENT '操作人'"),
            ('role', "varchar(64) DEFAULT NULL COMMENT '操作人角色'"),
            ('session_id', "varchar(128) DEFAULT NULL COMMENT '会话ID'"),
            ('trace_id', "varchar(64) DEFAULT NULL COMMENT '调用链追踪ID'"),
            ('result', "varchar(16) NOT NULL DEFAULT 'success' COMMENT '结果 success/fail/deny'"),
            ('detail', "longtext DEFAULT NULL COMMENT '明细 JSON'"),
            ('created_at', "datetime NOT NULL COMMENT '创建时间'"),
        ],
        'indexes': [
            ('PRIMARY KEY', '(`id`)'),
            ('KEY `idx_audit_tenant_time`', '(`tenant_id`,`created_at`)'),
            ('KEY `idx_audit_tenant_res`', '(`tenant_id`,`resource_type`,`resource_id`)'),
            ('KEY `idx_audit_trace`', '(`tenant_id`,`trace_id`)'),
        ],
    },
    'pbl_seed_record': {
        'comment': 'PBL 幂等种子注入记录（appcodes/模板/治理种子防重）',
        'columns': [
            ('tenant_id', "varchar(64) NOT NULL COMMENT '租户ID（* 表示全局种子）'"),
            ('seed_key', "varchar(128) NOT NULL COMMENT '种子键（模块:组:项）'"),
            ('seed_group', "varchar(64) DEFAULT NULL COMMENT '种子分组'"),
            ('module', "varchar(64) NOT NULL COMMENT '所属模块'"),
            ('payload', "longtext DEFAULT NULL COMMENT '种子内容 JSON'"),
            ('checksum', "varchar(64) DEFAULT NULL COMMENT '内容校验和（变更检测）'"),
            ('version', "int NOT NULL DEFAULT 1 COMMENT '注入版本'"),
            ('status', "varchar(16) NOT NULL DEFAULT 'applied' COMMENT 'applied/skipped/failed'"),
            ('created_at', "datetime NOT NULL COMMENT '创建时间'"),
            ('updated_at', "datetime NOT NULL COMMENT '更新时间'"),
        ],
        'indexes': [
            ('PRIMARY KEY', '(`id`)'),
            ('UNIQUE KEY `uk_seed_tenant_key`', '(`tenant_id`,`seed_key`)'),
            ('KEY `idx_seed_module`', '(`tenant_id`,`module`)'),
        ],
    },
}


def _assert_dialect(ddl_text, table=None):
    """方言自检：命中禁用 token 即抛错（mariadb 契约）"""
    up = ddl_text.upper()
    for token in FORBIDDEN_TOKENS:
        if token.upper() in up:
            raise DbError(
                message='DDL 含禁用元素 %r（方言必须为 %s，表=%s）' % (token, DIALECT, table),
                detail={'token': token, 'table': table, 'dialect': DIALECT},
            )
    return True


def ddl_of(table_name):
    """生成单表 CREATE TABLE 语句（mariadb 方言，IF NOT EXISTS 幂等）"""
    spec = TABLES.get(table_name)
    if not spec:
        raise DbError(message='未登记的表：%s' % table_name, detail={'table': table_name})

    cols = spec['columns']
    if not cols or cols[0][0] != 'tenant_id':
        raise DbError(
            message='表 %s 首列必须为 tenant_id（实际 %s）' % (table_name, cols[0][0] if cols else None),
            detail={'table': table_name},
        )

    lines = ["CREATE TABLE IF NOT EXISTS `%s` (" % table_name]
    lines.append("  `id` bigint NOT NULL AUTO_INCREMENT COMMENT '主键',")
    for name, decl in cols:
        lines.append("  `%s` %s," % (name, decl))
    for idx_name, idx_decl in spec['indexes']:
        lines.append("  %s %s," % (idx_name, idx_decl))
    # 去掉最后一行逗号
    lines[-1] = lines[-1].rstrip(',')
    lines.append(") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='%s';"
                 % spec.get('comment', table_name))
    ddl = '\n'.join(lines)
    _assert_dialect(ddl, table_name)
    return ddl


def all_ddl():
    """生成全部公共表 DDL（拼接文本，供 build.sh / apply_ddl.sh 使用）"""
    return '\n\n'.join(ddl_of(t) for t in sorted(TABLES.keys()))


def ensure_tables(conn=None, module='pbl_common'):
    """
    幂等建表（CREATE TABLE IF NOT EXISTS）。
    返回已确保的表名列表。conn 为 None 时自建连接。
    """
    from pbl_common.dbutil import execute, get_conn

    own = conn is None
    conn = conn or get_conn(module=module)
    created = []
    try:
        for table in sorted(TABLES.keys()):
            execute(ddl_of(table), conn=conn)
            created.append(table)
        if own:
            try:
                conn.commit()
            except Exception:  # noqa: BLE001
                pass
    finally:
        if own:
            try:
                conn.close()
            except Exception:  # noqa: BLE001
                pass
    return created


def table_names():
    """公共表名清单"""
    return sorted(TABLES.keys())