#!/usr/bin/env python3
import argparse
import sys
from pathlib import Path

import mysql.connector


def parse_env_file(env_path: Path):
    data = {}
    for raw in env_path.read_text(encoding="utf-8").splitlines():
        line = raw.strip()
        if not line or line.startswith("#") or "=" not in line:
            continue
        k, v = line.split("=", 1)
        data[k.strip()] = v.strip()
    return data


def split_sql_statements(sql_text: str):
    statements = []
    buf = []
    in_single = False
    in_double = False
    in_line_comment = False
    in_block_comment = False
    i = 0

    while i < len(sql_text):
        ch = sql_text[i]
        nxt = sql_text[i + 1] if i + 1 < len(sql_text) else ""

        if in_line_comment:
            if ch == "\n":
                in_line_comment = False
                buf.append(ch)
            i += 1
            continue

        if in_block_comment:
            if ch == "*" and nxt == "/":
                in_block_comment = False
                i += 2
            else:
                i += 1
            continue

        if not in_single and not in_double:
            if ch == "-" and nxt == "-":
                in_line_comment = True
                i += 2
                continue
            if ch == "#":
                in_line_comment = True
                i += 1
                continue
            if ch == "/" and nxt == "*":
                in_block_comment = True
                i += 2
                continue

        if ch == "'" and not in_double:
            in_single = not in_single
            buf.append(ch)
            i += 1
            continue

        if ch == '"' and not in_single:
            in_double = not in_double
            buf.append(ch)
            i += 1
            continue

        if ch == ";" and not in_single and not in_double:
            stmt = "".join(buf).strip()
            if stmt:
                statements.append(stmt)
            buf = []
            i += 1
            continue

        buf.append(ch)
        i += 1

    tail = "".join(buf).strip()
    if tail:
        statements.append(tail)
    return statements


def main():
    parser = argparse.ArgumentParser(description="Run SQL migration using mysql-connector")
    parser.add_argument("--env", default="backend/.env", help="Path to .env file")
    parser.add_argument("--sql", required=True, help="Path to SQL file")
    args = parser.parse_args()

    env = parse_env_file(Path(args.env))
    sql_path = Path(args.sql)
    if not sql_path.exists():
        print(f"[ERROR] SQL file not found: {sql_path}")
        return 1

    sql_text = sql_path.read_text(encoding="utf-8")
    statements = split_sql_statements(sql_text)
    if not statements:
        print("[ERROR] No SQL statements found")
        return 1

    conn = mysql.connector.connect(
        host=env.get("DB_HOST", "127.0.0.1"),
        port=int(env.get("DB_PORT", "3306")),
        user=env.get("DB_USER", "root"),
        password=env.get("DB_PASSWORD", ""),
        database=env.get("DB_NAME", ""),
    )

    try:
        cur = conn.cursor(dictionary=True)
        print(f"[INFO] Running {len(statements)} statements from {sql_path}")
        for idx, stmt in enumerate(statements, start=1):
            head = " ".join(stmt.split())[:120]
            cur.execute(stmt)
            if cur.with_rows:
                cur.fetchall()
            print(f"[OK] {idx:03d}: {head}")
        conn.commit()
        print("[INFO] Migration committed successfully")
    except Exception as e:
        conn.rollback()
        print(f"[FAIL] {e}")
        return 2
    finally:
        conn.close()

    return 0


if __name__ == "__main__":
    sys.exit(main())