"""
WeChat History REST API Server
Starts on port 19001. Queries WeChat chat history via wxhelper DLL (http://127.0.0.1:19088).

Usage:
    python history_api.py              # start on 0.0.0.0:19001
    python history_api.py --port 19001  # explicit port

Endpoints:
    GET  /                → API info
    GET  /health          → health check
    GET  /api/contacts    → list WeChat contacts (wxid + nickname)
    GET  /api/history?wxid=wxid_xxx&count=20  → query chat history
    POST /api/history     → same via JSON body {"wxid":"...","count":20}

Requires: wxhelper DLL injected and WeChat running (wechat_agent.py handles this).
"""

import os
import json
import time
import urllib.request
import urllib.error
from http.server import HTTPServer, BaseHTTPRequestHandler
from urllib.parse import urlparse, parse_qs
from datetime import datetime

os.environ["no_proxy"] = "*"
os.environ["NO_PROXY"] = "*"

# ── Configuration ──
WX_API = "http://127.0.0.1:19088"
DEFAULT_PORT = 19001
BOT_WXID = "wxid_7onnerpx2s2l22"
HOST = "0.0.0.0"

# ── Cached state ──
nickname_cache = {}
db_handle_cache = None

# ── wxhelper API helpers ──

def wxpost(path, data=None, timeout=10):
    """Call wxhelper HTTP API."""
    try:
        body = json.dumps(data or {}).encode()
        req = urllib.request.Request(
            WX_API + path,
            data=body,
            headers={"Content-Type": "application/json"}
        )
        r = urllib.request.urlopen(req, timeout=timeout)
        return json.loads(r.read().decode())
    except urllib.error.HTTPError as e:
        return json.loads(e.read().decode()) if e.code else {"code": -1}
    except Exception as e:
        return {"code": -1, "error": str(e)[:200]}


def get_db_handle():
    """Get handle for MSG*.db database containing MSG table. Cached after first call."""
    global db_handle_cache
    if db_handle_cache:
        return db_handle_cache
    r = wxpost("/api/getDBInfo", timeout=10)
    dbs = r.get("data") or []
    for db in dbs:
        dbname = db.get("databaseName", "")
        if dbname.startswith("MSG") and "Media" not in dbname:
                db_handle_cache = db.get("handle")
                return db_handle_cache
    return None


def get_nickname(wxid):
    """Get contact nickname from wxid, with caching."""
    if wxid in nickname_cache:
        return nickname_cache[wxid]
    r = wxpost("/api/getContactList", timeout=10)
    for c in (r.get("data") or []):
        if c.get("wxid") == wxid:
            nick = c.get("nickname") or c.get("customAccount") or wxid
            nickname_cache[wxid] = nick
            return nick
    nickname_cache[wxid] = wxid
    return wxid


def query_history(wxid, limit=10):
    """Query historical text messages from MSG table for a contact.
    Returns list of dicts: [{CreateTime, IsSender, Type, content}, ...]"""
    h = get_db_handle()
    if not h:
        return None
    limit_val = min(int(limit), 200)
    sql = (
        f"SELECT CreateTime, IsSender, Type, SubType, StrContent, DisplayContent, CompressContent, BytesExtra "
        f"FROM MSG WHERE StrTalker='{wxid}' AND Type IN ('1','49') "
        f"ORDER BY CreateTime DESC LIMIT {limit_val}"
    )
    r = wxpost("/api/execSql", {"dbHandle": h, "sql": sql}, timeout=15)
    data = r.get("data") or []
    if not data or len(data) < 2:
        return None
    # wxhelper returns [{value: [cols]}, {value: [row1]}, ...]
    rows = [item.get("value", item) if isinstance(item, dict) else item for item in data]
    rows = rows[1:]  # skip header
    rows.reverse()
    results = []
    for row in rows:
        content = (row[4] or "").strip() if len(row) > 4 else ""
        if not content and len(row) > 5:
            content = (row[5] or "").strip()
        # Type 49 (article link): extract URL from CompressContent or BytesExtra
        if not content and str(row[2]) == "49":
            try:
                import re
                # Try BytesExtra first (row[7])
                for idx in [7, 6]:
                    if idx < len(row) and row[idx]:
                        text = str(row[idx])
                        urls = re.findall(r'https?://[^\s\x00-\x1f<>\"\']{10,}', text)
                        if urls:
                            content = urls[0]
                            break
            except:
                pass
        if not content:
            if str(row[2]) == "49":
                content = "[文章链接]"
            else:
                continue
        results.append({
            "CreateTime": row[0],
            "IsSender": row[1],
            "Type": row[2],
            "content": content
        })
    return results


def format_history_json(wxid, rows):
    """Format raw MSG rows into JSON-serializable dict for API response."""
    sender_name = get_nickname(wxid)
    bot_name = get_nickname(BOT_WXID)
    if not rows:
        return {
            "ok": True, "wxid": wxid, "sender_name": sender_name,
            "count": 0, "messages": []
        }
    messages = []
    for row in rows:
        ts = int(row.get("CreateTime", 0))
        time_str = datetime.fromtimestamp(ts).strftime("%Y-%m-%d %H:%M:%S") if ts else ""
        is_sender = int(row.get("IsSender", 0))
        msg_type = int(row.get("Type", 1))
        content = row.get("content", "")
        messages.append({
            "time": time_str,
            "timestamp": ts,
            "sender": bot_name if is_sender else sender_name,
            "is_self": bool(is_sender),
            "type": msg_type,
            "type_name": {1: "text", 49: "link"}.get(msg_type, f"type_{msg_type}"),
            "content": content[:500]
        })
    return {
        "ok": True,
        "wxid": wxid,
        "sender_name": sender_name,
        "count": len(messages),
        "messages": messages
    }


def get_contacts():
    """Get all contacts from WeChat."""
    r = wxpost("/api/getContactList", timeout=10)
    contacts = r.get("data") or []
    # Update cache
    for c in contacts:
        wxid = c.get("wxid", "")
        nick = c.get("nickname") or c.get("customAccount") or wxid
        nickname_cache[wxid] = nick
    return [
        {
            "wxid": c.get("wxid", ""),
            "nickname": c.get("nickname", ""),
            "remark": c.get("remark", ""),
            "customAccount": c.get("customAccount", ""),
        }
        for c in contacts
    ]


def get_recent_chats(limit=20):
    """Get list of contacts with recent messages."""
    h = get_db_handle()
    if not h:
        return []
    sql = (
        f"SELECT DISTINCT StrTalker FROM MSG WHERE Type IN ('1','49') "
        f"LIMIT {min(limit, 50)}"
    )
    r = wxpost("/api/execSql", {"dbHandle": h, "sql": sql}, timeout=15)
    data = r.get("data") or []
    if not data or len(data) < 2:
        return []
    rows = [item.get("value", item) if isinstance(item, dict) else item for item in data]
    results = []
    for row in rows[1:]:
        wxid = (row[0] or "").strip()
        if not wxid or wxid in ("fmessage", "weixin", "wechat", "filehelper", "medianote", "floatbottle", "qmessage"):
            continue
        results.append({
            "wxid": wxid,
            "nickname": get_nickname(wxid),
            "last_message_time": None,
            "last_message_ts": 0,
            "message_count": 0,
        })
    return results


# ── HTTP Request Handler ──

class HistoryAPIHandler(BaseHTTPRequestHandler):

    def _send_json(self, data, status=200):
        """Send JSON response with proper headers."""
        body = json.dumps(data, ensure_ascii=False, indent=2).encode("utf-8")
        self.send_response(status)
        self.send_header("Content-Type", "application/json; charset=utf-8")
        self.send_header("Content-Length", str(len(body)))
        self.send_header("Access-Control-Allow-Origin", "*")
        self.end_headers()
        self.wfile.write(body)

    def _send_error_json(self, msg, status=400):
        self._send_json({"ok": False, "error": msg}, status=status)

    def _read_json_body(self):
        """Read and parse JSON request body."""
        length = int(self.headers.get("Content-Length", 0))
        if not length:
            return {}
        try:
            body = self.rfile.read(length)
            return json.loads(body)
        except json.JSONDecodeError:
            return {}

    def do_GET(self):
        parsed = urlparse(self.path)
        path = parsed.path.rstrip("/") or "/"
        params = parse_qs(parsed.query)

        # ── Root / Health ──
        if path in ("/", ""):
            self._send_json({
                "service": "WeChat History API",
                "version": "1.0",
                "port": DEFAULT_PORT,
                "wxhelper": WX_API,
                "endpoints": {
                    "GET /api/contacts": "List all WeChat contacts",
                    "GET /api/history": "Query chat history (params: wxid, count)",
                    "POST /api/history": "Same via JSON body",
                    "GET /api/recent": "Recent chats list",
                    "GET /health": "Health check",
                }
            })
            return

        if path == "/health":
            self._send_json({
                "status": "ok",
                "timestamp": datetime.now().isoformat(),
                "wxhelper": bool(get_db_handle())
            })
            return

        # ── Contacts ──
        if path == "/api/contacts":
            contacts = get_contacts()
            self._send_json({"ok": True, "count": len(contacts), "contacts": contacts})
            return

        # ── Recent Chats ──
        if path == "/api/recent":
            limit = int(params.get("limit", ["20"])[0])
            chats = get_recent_chats(limit)
            self._send_json({"ok": True, "count": len(chats), "chats": chats})
            return

        # ── History ──
        if path == "/api/history":
            wxid = params.get("wxid", [""])[0]
            count = params.get("count", ["10"])[0]
            if not wxid:
                self._send_error_json("Missing required parameter: wxid")
                return
            try:
                rows = query_history(wxid, count)
                result = format_history_json(wxid, rows)
                self._send_json(result)
            except Exception as e:
                self._send_error_json(str(e)[:200], status=500)
            return

        # ── 404 ──
        self._send_error_json(f"Not found: {path}", status=404)

    def do_POST(self):
        parsed = urlparse(self.path)
        path = parsed.path.rstrip("/") or "/"
        body = self._read_json_body()

        # ── History (POST) ──
        if path in ("/api/history", "/history"):
            wxid = (body.get("wxid", "") or "").strip()
            count = body.get("count", 10) or body.get("limit", 10)
            if not wxid:
                self._send_error_json("Missing required field: wxid")
                return
            try:
                rows = query_history(wxid, count)
                result = format_history_json(wxid, rows)
                self._send_json(result)
            except Exception as e:
                self._send_error_json(str(e)[:200], status=500)
            return

        # ── 404 ──
        self._send_error_json(f"Not found: {path}", status=404)

    def do_OPTIONS(self):
        """Handle CORS preflight."""
        self.send_response(200)
        self.send_header("Access-Control-Allow-Origin", "*")
        self.send_header("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
        self.send_header("Access-Control-Allow-Headers", "Content-Type")
        self.end_headers()

    def log_message(self, *args):
        # Suppress default access logs to stdout
        pass


# ── Main ──

def main():
    import sys
    port = DEFAULT_PORT
    if "--port" in sys.argv:
        idx = sys.argv.index("--port")
        if idx + 1 < len(sys.argv):
            port = int(sys.argv[idx + 1])

    # Check wxhelper connectivity
    print(f"[History API] Checking wxhelper at {WX_API}...")
    try:
        r = wxpost("/api/checkLogin", timeout=5)
        if r.get("code") == 1:
            print("[History API] wxhelper ONLINE")
            db_handle = get_db_handle()
            print(f"[History API] DB handle: {db_handle or 'NOT FOUND'}")
        else:
            print(f"[History API] WARNING: wxhelper not logged in: {r}")
    except Exception as e:
        print(f"[History API] WARNING: Cannot reach wxhelper: {e}")

    # Start server
    server = HTTPServer((HOST, port), HistoryAPIHandler)
    print(f"[History API] Listening on http://{HOST}:{port}")
    print(f"[History API] Endpoints:")
    print(f"  GET  http://localhost:{port}/")
    print(f"  GET  http://localhost:{port}/health")
    print(f"  GET  http://localhost:{port}/api/contacts")
    print(f"  GET  http://localhost:{port}/api/recent")
    print(f"  GET  http://localhost:{port}/api/history?wxid=wxid_xxx&count=20")
    print(f"  POST http://localhost:{port}/api/history")

    try:
        server.serve_forever()
    except KeyboardInterrupt:
        print("\n[History API] Shutting down...")
        server.shutdown()


if __name__ == "__main__":
    main()