#!/usr/bin/env python3
"""
迁移到新数据库 knowhub：从 knowledge_hub 读数据，写入 knowhub。
13 张表：5 实体 + 8 关联。

只使用 CREATE TABLE / INSERT / DROP TABLE，不执行 ALTER。
每步幂等，可安全重跑。
"""

import os
import json
import psycopg2
from psycopg2.extras import RealDictCursor, Json
from dotenv import load_dotenv

_script_dir = os.path.dirname(os.path.abspath(__file__))
_project_root = os.path.normpath(os.path.join(_script_dir, '..', '..', '..'))
load_dotenv(os.path.join(_project_root, '.env'))


def connect(db_name):
    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=db_name,
        connect_timeout=10
    )
    conn.autocommit = True
    return conn


# ─── 13 张表的 CREATE 语句 ────────────────────────────────────────────────────

CREATE_TABLES = [
    # === 实体表 (5) ===
    """
    CREATE TABLE IF NOT EXISTS knowledge (
        id                VARCHAR PRIMARY KEY,
        task_embedding    float4[],
        content_embedding float4[],
        message_id        VARCHAR,
        task              VARCHAR,
        content           TEXT,
        types             TEXT[],
        tags              JSONB DEFAULT '{}',
        tag_keys          TEXT[],
        scopes            TEXT[],
        owner             VARCHAR,
        source            JSONB DEFAULT '{}',
        eval              JSONB DEFAULT '{}',
        created_at        BIGINT,
        updated_at        BIGINT,
        status            VARCHAR DEFAULT 'approved'
    )
    """,
    """
    CREATE TABLE IF NOT EXISTS resource (
        id           TEXT PRIMARY KEY,
        title        TEXT,
        body         TEXT,
        secure_body  TEXT,
        content_type TEXT,
        metadata     JSONB DEFAULT '{}',
        sort_order   INTEGER DEFAULT 0,
        submitted_by TEXT,
        created_at   BIGINT,
        updated_at   BIGINT
    )
    """,
    """
    CREATE TABLE IF NOT EXISTS requirement (
        id           VARCHAR PRIMARY KEY,
        description  TEXT,
        source_nodes JSONB DEFAULT '[]',
        status       VARCHAR DEFAULT '未满足',
        match_result TEXT,
        embedding    float4[]
    )
    """,
    """
    CREATE TABLE IF NOT EXISTS capability (
        id          VARCHAR PRIMARY KEY,
        name        VARCHAR,
        criterion   TEXT,
        description TEXT,
        embedding   float4[]
    )
    """,
    """
    CREATE TABLE IF NOT EXISTS tool (
        id           VARCHAR PRIMARY KEY,
        name         VARCHAR,
        version      VARCHAR,
        introduction TEXT,
        tutorial     TEXT,
        input        JSONB DEFAULT '""',
        output       JSONB DEFAULT '""',
        updated_time BIGINT,
        status       VARCHAR DEFAULT '未接入',
        embedding    float4[]
    )
    """,
    # === 实体链 (2) ===
    """
    CREATE TABLE IF NOT EXISTS requirement_capability (
        requirement_id VARCHAR NOT NULL,
        capability_id  VARCHAR NOT NULL,
        PRIMARY KEY (requirement_id, capability_id)
    )
    """,
    """
    CREATE TABLE IF NOT EXISTS capability_tool (
        capability_id VARCHAR NOT NULL,
        tool_id       VARCHAR NOT NULL,
        description   TEXT DEFAULT '',
        PRIMARY KEY (capability_id, tool_id)
    )
    """,
    # === 知识链 (3) ===
    """
    CREATE TABLE IF NOT EXISTS requirement_knowledge (
        requirement_id VARCHAR NOT NULL,
        knowledge_id   VARCHAR NOT NULL,
        PRIMARY KEY (requirement_id, knowledge_id)
    )
    """,
    """
    CREATE TABLE IF NOT EXISTS capability_knowledge (
        capability_id VARCHAR NOT NULL,
        knowledge_id  VARCHAR NOT NULL,
        PRIMARY KEY (capability_id, knowledge_id)
    )
    """,
    """
    CREATE TABLE IF NOT EXISTS tool_knowledge (
        tool_id      VARCHAR NOT NULL,
        knowledge_id VARCHAR NOT NULL,
        PRIMARY KEY (tool_id, knowledge_id)
    )
    """,
    # === 来源链 (1) ===
    """
    CREATE TABLE IF NOT EXISTS knowledge_resource (
        knowledge_id VARCHAR NOT NULL,
        resource_id  VARCHAR NOT NULL,
        PRIMARY KEY (knowledge_id, resource_id)
    )
    """,
    # === 知识间关系 (1) ===
    """
    CREATE TABLE IF NOT EXISTS knowledge_relation (
        source_id     VARCHAR NOT NULL,
        target_id     VARCHAR NOT NULL,
        relation_type VARCHAR NOT NULL,
        PRIMARY KEY (source_id, target_id, relation_type)
    )
    """,
    # === 执行层索引 (1) ===
    """
    CREATE TABLE IF NOT EXISTS tool_provider (
        tool_id     VARCHAR NOT NULL,
        provider_id VARCHAR NOT NULL,
        PRIMARY KEY (tool_id, provider_id)
    )
    """,
]


# ─── 数据迁移 ─────────────────────────────────────────────────────────────────

def _parse_json(val):
    if val is None:
        return [] if not isinstance(val, dict) else {}
    if isinstance(val, (list, dict)):
        return val
    try:
        return json.loads(val)
    except (json.JSONDecodeError, TypeError):
        return []


# JSONB 列名集合（值需要 Json() 包装，否则 psycopg2 当纯文本发送导致类型错误）
_JSONB_COLS = {'tags', 'source', 'eval', 'metadata', 'source_nodes', 'input', 'output'}


def _adapt(col_name, v):
    """psycopg2 序列化适配：JSONB 列 → Json()，数组列 → 原生 list"""
    if v is None:
        return None
    if col_name in _JSONB_COLS:
        return Json(v)
    if isinstance(v, dict):
        return Json(v)  # 未在 _JSONB_COLS 中的 dict（兜底）
    return v  # float4[] / TEXT[] / 标量


def migrate_entities(old_cur, new_cur):
    """迁移 5 张实体表"""

    # knowledge: 排除 resource_ids, relationships, support_capability, tools
    KNOWLEDGE_COLS = (
        'id, task_embedding, content_embedding, message_id, task, content, '
        'types, tags, tag_keys, scopes, owner, source, eval, '
        'created_at, updated_at, status'
    )
    _migrate_table(old_cur, new_cur, 'knowledge', 'knowledge', KNOWLEDGE_COLS)

    # resource: 旧表叫 resources，新表叫 resource
    RESOURCE_COLS = (
        'id, title, body, secure_body, content_type, metadata, '
        'sort_order, submitted_by, created_at, updated_at'
    )
    _migrate_table(old_cur, new_cur, 'resource', 'resources', RESOURCE_COLS)

    # requirement: 排除 atomics
    REQ_COLS = 'id, description, source_nodes, status, match_result, embedding'
    _migrate_table(old_cur, new_cur, 'requirement', 'requirement', REQ_COLS)

    # capability: 排除 requirements, implements, tools, source_knowledge
    CAP_COLS = 'id, name, criterion, description, embedding'
    _migrate_table(old_cur, new_cur, 'capability', 'capability', CAP_COLS)

    # tool: 排除 implemented_tool_ids (旧表已无 JSONB 关联列)
    TOOL_COLS = 'id, name, version, introduction, tutorial, input, output, updated_time, status, embedding'
    _migrate_table(old_cur, new_cur, 'tool', 'tool', TOOL_COLS)


def _migrate_table(old_cur, new_cur, new_table, old_table, columns):
    """通用表迁移：从旧表读指定列，写入新表"""
    new_cur.execute(f"SELECT COUNT(*) FROM {new_table}")
    existing = list(new_cur.fetchone().values())[0]
    if existing > 0:
        print(f"  {new_table}: 已有 {existing} 行，跳过", flush=True)
        return

    old_cur.execute(f"SELECT {columns} FROM {old_table}")
    rows = old_cur.fetchall()
    if not rows:
        print(f"  {new_table}: 源表为空", flush=True)
        return

    col_names = [c.strip() for c in columns.split(',')]
    placeholders = ', '.join(['%s'] * len(col_names))
    total = len(rows)
    count = 0
    errors = 0
    for i, row in enumerate(rows):
        values = [_adapt(c, row[c]) for c in col_names]
        try:
            new_cur.execute(
                f"INSERT INTO {new_table} ({columns}) VALUES ({placeholders})",
                values)
            count += 1
        except Exception as e:
            if 'duplicate key' not in str(e):
                errors += 1
                if errors <= 3:  # 只打印前 3 个错误
                    print(f"    [!] {new_table} row {row.get('id','?')}: {e}", flush=True)
        if (i + 1) % 50 == 0 or i + 1 == total:
            print(f"  {new_table}: {i+1}/{total} ({count} ok, {errors} err)", flush=True)
    print(f"  {new_table}: 完成 {count}/{total} 行" + (f" ({errors} 错误)" if errors else ""), flush=True)


def migrate_junctions(old_cur, new_cur):
    """迁移关联表数据"""

    # 直接复制旧关联表（已有正确数据）
    for table, cols in [
        ('requirement_capability', 'requirement_id, capability_id'),
        ('capability_tool', 'capability_id, tool_id, description'),
        ('capability_knowledge', 'capability_id, knowledge_id'),
        ('tool_knowledge', 'tool_id, knowledge_id'),
    ]:
        _migrate_junction(old_cur, new_cur, table, table, cols)

    # knowledge_resource: 从 knowledge.resource_ids 数组提取
    _migrate_knowledge_resource(old_cur, new_cur)

    # knowledge_relation: 从 knowledge.relationships JSONB 提取
    _migrate_knowledge_relation(old_cur, new_cur)

    # requirement_knowledge: 旧库没有这张表，跳过
    print("  requirement_knowledge: 旧库无数据（新增表）", flush=True)

    # tool_provider: 旧库没有这张表，跳过
    print("  tool_provider: 旧库无数据（新增表）", flush=True)


def _migrate_junction(old_cur, new_cur, new_table, old_table, cols):
    """复制关联表"""
    new_cur.execute(f"SELECT COUNT(*) FROM {new_table}")
    existing = list(new_cur.fetchone().values())[0]
    if existing > 0:
        print(f"  {new_table}: 已有 {existing} 行，跳过", flush=True)
        return

    try:
        old_cur.execute(f"SELECT {cols} FROM {old_table}")
    except Exception as e:
        print(f"  {new_table}: 旧表 {old_table} 不可读 ({e})，跳过", flush=True)
        return

    rows = old_cur.fetchall()
    if not rows:
        print(f"  {new_table}: 源表为空", flush=True)
        return

    col_names = [c.strip() for c in cols.split(',')]
    placeholders = ', '.join(['%s'] * len(col_names))
    count = 0
    for row in rows:
        values = [_adapt(c, row[c]) for c in col_names]
        try:
            new_cur.execute(
                f"INSERT INTO {new_table} ({cols}) VALUES ({placeholders}) ON CONFLICT DO NOTHING",
                values)
            count += 1
        except Exception as e:
            print(f"    [!] {new_table}: {e}", flush=True)
    print(f"  {new_table}: {count}/{len(rows)} 行", flush=True)


def _migrate_knowledge_resource(old_cur, new_cur):
    """从 knowledge.resource_ids 数组提取到 knowledge_resource 关联表"""
    new_cur.execute("SELECT COUNT(*) FROM knowledge_resource")
    if list(new_cur.fetchone().values())[0] > 0:
        print("  knowledge_resource: 已有数据，跳过", flush=True)
        return

    # 预加载有效 resource ID
    new_cur.execute("SELECT id FROM resource")
    valid_resources = {list(r.values())[0] for r in new_cur.fetchall()}

    old_cur.execute("SELECT id, resource_ids FROM knowledge WHERE resource_ids IS NOT NULL")
    rows = old_cur.fetchall()
    count = 0
    skipped = 0
    for row in rows:
        rids = _parse_json(row['resource_ids'])
        if not isinstance(rids, list):
            continue
        for rid in rids:
            if rid in valid_resources:
                try:
                    new_cur.execute(
                        "INSERT INTO knowledge_resource (knowledge_id, resource_id) VALUES (%s, %s) ON CONFLICT DO NOTHING",
                        (row['id'], rid))
                    count += 1
                except Exception as e:
                    print(f"    [!] knowledge_resource: {e}", flush=True)
            else:
                skipped += 1
    print(f"  knowledge_resource: {count} 行 (跳过悬空引用 {skipped})", flush=True)


def _migrate_knowledge_relation(old_cur, new_cur):
    """从 knowledge.relationships JSONB 提取到 knowledge_relation 关联表"""
    new_cur.execute("SELECT COUNT(*) FROM knowledge_relation")
    if list(new_cur.fetchone().values())[0] > 0:
        print("  knowledge_relation: 已有数据，跳过", flush=True)
        return

    old_cur.execute("SELECT id, relationships FROM knowledge WHERE relationships IS NOT NULL")
    rows = old_cur.fetchall()
    count = 0
    for row in rows:
        rels = _parse_json(row['relationships'])
        if not isinstance(rels, list):
            continue
        for rel in rels:
            if isinstance(rel, dict) and 'type' in rel and 'target' in rel:
                try:
                    new_cur.execute(
                        "INSERT INTO knowledge_relation (source_id, target_id, relation_type) VALUES (%s, %s, %s) ON CONFLICT DO NOTHING",
                        (row['id'], rel['target'], rel['type']))
                    count += 1
                except Exception as e:
                    print(f"    [!] knowledge_relation: {e}", flush=True)
    print(f"  knowledge_relation: {count} 行", flush=True)


# ─── 主流程 ───────────────────────────────────────────────────────────────────

def main():
    OLD_DB = os.getenv('KNOWHUB_DB_NAME')
    NEW_DB = 'knowhub'

    print("=" * 60, flush=True)
    print(f"迁移: {OLD_DB} → {NEW_DB}", flush=True)
    print("=" * 60, flush=True)

    # Step 1: 建表
    print(f"\n[1/3] 在 {NEW_DB} 建表...", flush=True)
    new_conn = connect(NEW_DB)
    new_cur = new_conn.cursor()
    for sql in CREATE_TABLES:
        new_cur.execute(sql)
    new_cur.close()

    # 验证
    new_cur = new_conn.cursor()
    new_cur.execute("SELECT tablename FROM pg_tables WHERE schemaname='public' ORDER BY tablename")
    tables = [r[0] for r in new_cur.fetchall()]
    print(f"  {len(tables)} 张表: {', '.join(tables)}", flush=True)
    new_cur.close()

    # Step 2: 迁移实体数据（每次新建旧库连接，避免长连接超时）
    print(f"\n[2/3] 迁移实体数据...", flush=True)
    old_conn = connect(OLD_DB)
    old_cur = old_conn.cursor(cursor_factory=RealDictCursor)
    new_cur = new_conn.cursor(cursor_factory=RealDictCursor)
    migrate_entities(old_cur, new_cur)
    old_cur.close()
    old_conn.close()

    # Step 3: 迁移关联数据（每批独立连接旧库，防止长连接超时）
    print(f"\n[3/3] 迁移关联数据...", flush=True)

    # 3a: 复制旧关联表
    old_conn = connect(OLD_DB)
    old_cur = old_conn.cursor(cursor_factory=RealDictCursor)
    for table, cols in [
        ('requirement_capability', 'requirement_id, capability_id'),
        ('capability_tool', 'capability_id, tool_id, description'),
        ('capability_knowledge', 'capability_id, knowledge_id'),
        ('tool_knowledge', 'tool_id, knowledge_id'),
    ]:
        _migrate_junction(old_cur, new_cur, table, table, cols)
    old_cur.close()
    old_conn.close()

    # 3b: knowledge_resource（重新连接）
    old_conn = connect(OLD_DB)
    old_cur = old_conn.cursor(cursor_factory=RealDictCursor)
    _migrate_knowledge_resource(old_cur, new_cur)
    old_cur.close()
    old_conn.close()

    # 3c: knowledge_relation（重新连接）
    old_conn = connect(OLD_DB)
    old_cur = old_conn.cursor(cursor_factory=RealDictCursor)
    _migrate_knowledge_relation(old_cur, new_cur)
    old_cur.close()
    old_conn.close()

    # 新增表无旧数据
    print("  requirement_knowledge: 新增表，无旧数据", flush=True)
    print("  tool_provider: 新增表，无旧数据", flush=True)

    # 验证
    print(f"\n{'=' * 60}", flush=True)
    print(f"验证 {NEW_DB}:", flush=True)
    print(f"{'=' * 60}", flush=True)
    for t in tables:
        new_cur.execute(f"SELECT COUNT(*) as c FROM {t}")
        cnt = new_cur.fetchone()['c']
        print(f"  {t}: {cnt} rows", flush=True)

    print(f"\n{'=' * 60}", flush=True)
    print("迁移完成！", flush=True)
    print(f"下一步：将 .env 中 KNOWHUB_DB_NAME 改为 {NEW_DB}", flush=True)
    print(f"{'=' * 60}", flush=True)

    new_cur.close()
    new_conn.close()


if __name__ == '__main__':
    main()