"""
PostgreSQL tool 存储封装

用于存储和检索工具数据，支持向量检索。
表名：tool（从 tool_table 迁移）
"""

import os
import json
import psycopg2
from psycopg2.extras import RealDictCursor
from typing import List, Dict, Optional
from dotenv import load_dotenv
from knowhub.knowhub_db.cascade import cascade_delete

load_dotenv()

# 关联字段子查询
_REL_SUBQUERIES = """
    (SELECT COALESCE(json_agg(ct.capability_id), '[]'::json)
     FROM capability_tool ct WHERE ct.tool_id = tool.id) AS capability_ids,
    (SELECT COALESCE(json_agg(tk.knowledge_id), '[]'::json)
     FROM tool_knowledge tk WHERE tk.tool_id = tool.id) AS knowledge_ids,
    (SELECT COALESCE(json_agg(tp.provider_id), '[]'::json)
     FROM tool_provider tp WHERE tp.tool_id = tool.id) AS provider_ids
"""

_BASE_FIELDS = "id, name, version, introduction, tutorial, input, output, updated_time, status"

_SELECT_FIELDS = f"{_BASE_FIELDS}, {_REL_SUBQUERIES}"


class PostgreSQLToolStore:
    def __init__(self):
        """初始化 PostgreSQL 连接"""
        self.conn = psycopg2.connect(
            host=os.getenv('KNOWHUB_DB'),
            port=int(os.getenv('KNOWHUB_PORT', 5432)),
            user=os.getenv('KNOWHUB_USER'),
            password=os.getenv('KNOWHUB_PASSWORD'),
            database=os.getenv('KNOWHUB_DB_NAME')
        )
        self.conn.autocommit = False
        print(f"[PostgreSQL Tool] 已连接到远程数据库: {os.getenv('KNOWHUB_DB')}")

    def _reconnect(self):
        self.conn = psycopg2.connect(
            host=os.getenv('KNOWHUB_DB'),
            port=int(os.getenv('KNOWHUB_PORT', 5432)),
            user=os.getenv('KNOWHUB_USER'),
            password=os.getenv('KNOWHUB_PASSWORD'),
            database=os.getenv('KNOWHUB_DB_NAME')
        )
        self.conn.autocommit = False

    def _ensure_connection(self):
        if self.conn.closed != 0:
            self._reconnect()
        else:
            try:
                c = self.conn.cursor()
                c.execute("SELECT 1")
                c.close()
            except (psycopg2.OperationalError, psycopg2.InterfaceError):
                self._reconnect()

    def _get_cursor(self):
        self._ensure_connection()
        return self.conn.cursor(cursor_factory=RealDictCursor)

    def insert_or_update(self, tool: Dict):
        """插入或更新工具"""
        cursor = self._get_cursor()
        try:
            cursor.execute("""
                INSERT INTO tool (
                    id, name, version, introduction, tutorial, input, output,
                    updated_time, status, embedding
                ) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
                ON CONFLICT (id) DO UPDATE SET
                    name = EXCLUDED.name,
                    version = EXCLUDED.version,
                    introduction = EXCLUDED.introduction,
                    tutorial = EXCLUDED.tutorial,
                    input = EXCLUDED.input,
                    output = EXCLUDED.output,
                    updated_time = EXCLUDED.updated_time,
                    status = EXCLUDED.status,
                    embedding = EXCLUDED.embedding
            """, (
                tool['id'],
                tool.get('name', ''),
                tool.get('version'),
                tool.get('introduction', ''),
                tool.get('tutorial', ''),
                json.dumps(tool.get('input', '')),
                json.dumps(tool.get('output', '')),
                tool.get('updated_time', 0),
                tool.get('status', '未接入'),
                tool.get('embedding'),
            ))
            # 写入关联表
            tool_id = tool['id']
            if 'capability_ids' in tool:
                cursor.execute("DELETE FROM capability_tool WHERE tool_id = %s", (tool_id,))
                for cap_id in tool['capability_ids']:
                    cursor.execute(
                        "INSERT INTO capability_tool (capability_id, tool_id) VALUES (%s, %s) ON CONFLICT DO NOTHING",
                        (cap_id, tool_id))
            if 'knowledge_ids' in tool:
                cursor.execute("DELETE FROM tool_knowledge WHERE tool_id = %s", (tool_id,))
                for kid in tool['knowledge_ids']:
                    cursor.execute(
                        "INSERT INTO tool_knowledge (tool_id, knowledge_id) VALUES (%s, %s) ON CONFLICT DO NOTHING",
                        (tool_id, kid))
            if 'provider_ids' in tool:
                cursor.execute("DELETE FROM tool_provider WHERE tool_id = %s", (tool_id,))
                for pid in tool['provider_ids']:
                    cursor.execute(
                        "INSERT INTO tool_provider (tool_id, provider_id) VALUES (%s, %s) ON CONFLICT DO NOTHING",
                        (tool_id, pid))
            self.conn.commit()
        finally:
            cursor.close()

    def get_by_id(self, tool_id: str) -> Optional[Dict]:
        """根据 ID 获取工具"""
        cursor = self._get_cursor()
        try:
            cursor.execute(f"""
                SELECT {_SELECT_FIELDS}
                FROM tool WHERE id = %s
            """, (tool_id,))
            result = cursor.fetchone()
            return self._format_result(result) if result else None
        finally:
            cursor.close()

    def search(self, query_embedding: List[float], limit: int = 10, status: Optional[str] = None) -> List[Dict]:
        """向量检索工具"""
        cursor = self._get_cursor()
        try:
            if status:
                sql = f"""
                    SELECT {_SELECT_FIELDS},
                           1 - (embedding <=> %s::real[]) as score
                    FROM tool
                    WHERE embedding IS NOT NULL AND status = %s
                    ORDER BY embedding <=> %s::real[]
                    LIMIT %s
                """
                params = [query_embedding, status, query_embedding, limit]
            else:
                sql = f"""
                    SELECT {_SELECT_FIELDS},
                           1 - (embedding <=> %s::real[]) as score
                    FROM tool
                    WHERE embedding IS NOT NULL
                    ORDER BY embedding <=> %s::real[]
                    LIMIT %s
                """
                params = [query_embedding, query_embedding, limit]
            cursor.execute(sql, params)
            results = cursor.fetchall()
            return [self._format_result(r) for r in results]
        finally:
            cursor.close()

    def list_all(self, limit: int = 100, offset: int = 0, status: Optional[str] = None) -> List[Dict]:
        """列出工具"""
        cursor = self._get_cursor()
        try:
            if status:
                cursor.execute(f"""
                    SELECT {_SELECT_FIELDS}
                    FROM tool
                    WHERE status = %s
                    ORDER BY updated_time DESC
                    LIMIT %s OFFSET %s
                """, (status, limit, offset))
            else:
                cursor.execute(f"""
                    SELECT {_SELECT_FIELDS}
                    FROM tool
                    ORDER BY updated_time DESC
                    LIMIT %s OFFSET %s
                """, (limit, offset))
            results = cursor.fetchall()
            return [self._format_result(r) for r in results]
        finally:
            cursor.close()

    def update(self, tool_id: str, updates: Dict):
        """更新工具字段"""
        cursor = self._get_cursor()
        try:
            # 分离关联字段
            cap_ids = updates.pop('capability_ids', None)
            knowledge_ids = updates.pop('knowledge_ids', None)
            provider_ids = updates.pop('provider_ids', None)

            if updates:
                set_parts = []
                params = []
                json_fields = ('input', 'output')
                for key, value in updates.items():
                    set_parts.append(f"{key} = %s")
                    if key in json_fields:
                        params.append(json.dumps(value))
                    else:
                        params.append(value)
                params.append(tool_id)
                cursor.execute(
                    f"UPDATE tool SET {', '.join(set_parts)} WHERE id = %s",
                    params
                )

            # 更新关联表
            if cap_ids is not None:
                cursor.execute("DELETE FROM capability_tool WHERE tool_id = %s", (tool_id,))
                for cap_id in cap_ids:
                    cursor.execute(
                        "INSERT INTO capability_tool (capability_id, tool_id) VALUES (%s, %s) ON CONFLICT DO NOTHING",
                        (cap_id, tool_id))

            if knowledge_ids is not None:
                cursor.execute("DELETE FROM tool_knowledge WHERE tool_id = %s", (tool_id,))
                for kid in knowledge_ids:
                    cursor.execute(
                        "INSERT INTO tool_knowledge (tool_id, knowledge_id) VALUES (%s, %s) ON CONFLICT DO NOTHING",
                        (tool_id, kid))

            if provider_ids is not None:
                cursor.execute("DELETE FROM tool_provider WHERE tool_id = %s", (tool_id,))
                for pid in provider_ids:
                    cursor.execute(
                        "INSERT INTO tool_provider (tool_id, provider_id) VALUES (%s, %s) ON CONFLICT DO NOTHING",
                        (tool_id, pid))

            self.conn.commit()
        finally:
            cursor.close()

    def add_knowledge(self, tool_id: str, knowledge_id: str):
        """向工具添加一条知识关联（不删除已有关联）"""
        cursor = self._get_cursor()
        try:
            cursor.execute(
                "INSERT INTO tool_knowledge (tool_id, knowledge_id) VALUES (%s, %s) ON CONFLICT DO NOTHING",
                (tool_id, knowledge_id))
            self.conn.commit()
        finally:
            cursor.close()

    def delete(self, tool_id: str):
        """删除工具及其关联表记录"""
        cursor = self._get_cursor()
        try:
            cascade_delete(cursor, 'tool', tool_id)
            self.conn.commit()
        finally:
            cursor.close()

    def count(self, status: Optional[str] = None) -> int:
        """统计工具总数"""
        cursor = self._get_cursor()
        try:
            if status:
                cursor.execute("SELECT COUNT(*) as count FROM tool WHERE status = %s", (status,))
            else:
                cursor.execute("SELECT COUNT(*) as count FROM tool")
            return cursor.fetchone()['count']
        finally:
            cursor.close()

    def _format_result(self, row: Dict) -> Dict:
        """格式化查询结果，将 JSON 字符串解析为对象"""
        if not row:
            return None
        result = dict(row)
        for field in ('input', 'output'):
            if field in result and isinstance(result[field], str):
                try:
                    result[field] = json.loads(result[field]) if result[field].strip() else None
                except json.JSONDecodeError:
                    result[field] = None
        # 关联字段（来自 junction table 子查询）
        for field in ('capability_ids', 'knowledge_ids', 'provider_ids'):
            if field in result and isinstance(result[field], str):
                result[field] = json.loads(result[field])
            elif field in result and result[field] is None:
                result[field] = []
        return result

    def close(self):
        if self.conn:
            self.conn.close()