import os, sys, json, subprocess
import boto3
from urllib.parse import urlparse
from flask import Flask, request, jsonify
from flask_cors import CORS

app = Flask(__name__, static_folder="../dist", static_url_path="")
CORS(app)

def parse_connection_string(conn_str, default_user='', default_pass=''):
    if '://' in conn_str:
        parsed = urlparse(conn_str)
        return {
            'host': parsed.hostname,
            'user': parsed.username or default_user,
            'pass': parsed.password or default_pass,
            'db': parsed.path.lstrip('/') if parsed.path else ''
        }
    else:
        return {
            'host': conn_str,
            'user': default_user,
            'pass': default_pass,
            'db': ''
        }

@app.after_request
def add_no_cache_headers(response):
    return response

# =========================
# React
# =========================
@app.route("/")
def frontend():
    return app.send_static_file("index.html")

@app.route("/<path:path>")
def assets(path):
    return app.send_static_file(path)

# =========================
# CONFIG
# =========================
MIGRATORS = {
    "mysql_mysql": {
        "script": "mysql_migrator.py",
        "progress": "mysql_progress.json"
    },
    "psql_psql": {
        "script": "psql_psql_migrator.py",
        "progress": "pg_progress.json"
    },
    "psql_s3": {
        "script": "pg_s3_migrator.py",
        "progress": "psql_progress.json"
    },
    "s3_s3": {
        "script": "s3_s3_migrator.py",
        "progress": "migration_progress.json"
    }
}

# =========================
# GET SCHEMAS
# =========================
@app.route("/api/get_schemas", methods=["POST"])
def get_schemas():
    data = request.json
    mtype = data.get("type")

    if mtype == "mysql_mysql":
        conn = parse_connection_string(data['host'], data['user'], data['pass'])
        cmd = f"mysql -h {conn['host']} -u {conn['user']} -p{conn['pass']} -e \"SHOW DATABASES;\""
        try:
            res = subprocess.check_output(cmd, shell=True).decode().splitlines()
            ignore = ("Database","information_schema","mysql","performance_schema","sys")
            return jsonify({"schemas": [r for r in res if r and r not in ignore], "error": None})
        except Exception as e:
            return jsonify({"schemas": [], "error": str(e)})

    if mtype == "psql_psql":
        conn = parse_connection_string(data['host'], data['user'], data['pass'])
        cmd = (
            f"PGPASSWORD='{conn['pass']}' psql -h {conn['host']} -U {conn['user']} -t -c "
            "\"SELECT schema_name FROM information_schema.schemata "
            "WHERE schema_name NOT IN ('information_schema','pg_catalog');\""
        )
        try:
            res = subprocess.check_output(cmd, shell=True).decode().splitlines()
            return jsonify({"schemas": [r.strip() for r in res if r.strip()], "error": None})
        except Exception as e:
            return jsonify({"schemas": [], "error": str(e)})

    return jsonify([])

# =========================
# GET TABLES
# =========================
@app.route("/api/get_tables", methods=["POST"])
def get_tables():
    data = request.json
    mtype = data.get("type")
    tables = []

    if mtype == "mysql_mysql":
        conn = parse_connection_string(data['host'], data['user'], data['pass'])
        for db in data["schemas"]:
            cmd = f"mysql -h {conn['host']} -u {conn['user']} -p{conn['pass']} -D {db} -e \"SHOW TABLES;\""
            try:
                res = subprocess.check_output(cmd, shell=True).decode().splitlines()
                tables += [f"{db}.{t}" for t in res if not t.startswith("Tables")]
            except:
                pass

    if mtype == "psql_psql":
        conn = parse_connection_string(data['host'], data['user'], data['pass'])
        for schema in data["schemas"]:
            cmd = (
                f"PGPASSWORD='{conn['pass']}' psql -h {conn['host']} -U {conn['user']} -t -c "
                f"\"SELECT table_name FROM information_schema.tables WHERE table_schema='{schema}';\""
            )
            try:
                res = subprocess.check_output(cmd, shell=True).decode().splitlines()
                tables += [f"{schema}.{t.strip()}" for t in res if t.strip()]
            except:
                pass

    return jsonify({"tables": tables, "error": None})

# =========================
# LIST S3 BUCKETS
# =========================
@app.route("/api/list_buckets", methods=["POST"])
def list_buckets():
    data = request.json
    if not data:
        return jsonify({"success": False, "error": "No JSON data provided"}), 400
    required_keys = ["AWS_SRC_ACCESS_KEY", "AWS_SRC_SECRET_KEY"]
    for key in required_keys:
        if key not in data or not data[key]:
            return jsonify({"success": False, "error": f"Missing or empty required field: {key}"}), 400
    try:
        s3 = boto3.client(
            "s3",
            aws_access_key_id=data["AWS_SRC_ACCESS_KEY"],
            aws_secret_access_key=data["AWS_SRC_SECRET_KEY"],
            region_name=data.get("AWS_SRC_REGION", "us-east-1")
        )
        return jsonify({"success": True, "buckets": [b["Name"] for b in s3.list_buckets()["Buckets"]]})
    except Exception as e:
        return jsonify({"success": False, "error": str(e)}), 400

# =========================
# MIGRATE
# =========================
@app.route("/api/migrate", methods=["POST"])
def migrate():
    data = request.json
    mtype = data.get("type")

    if mtype not in MIGRATORS:
        return jsonify({"error": "Invalid migrator type"}), 400

    # Parse connection string for mysql_mysql
    if mtype == "mysql_mysql":
        if 'SRC_HOST' in data:
            conn = parse_connection_string(data['SRC_HOST'], data.get('SRC_USER', ''), data.get('SRC_PASS', ''))
            data['SRC_HOST'] = conn['host']
            if conn['user']: data['SRC_USER'] = conn['user']
            if conn['pass']: data['SRC_PASS'] = conn['pass']
        if 'DEST_HOST' in data:
            conn = parse_connection_string(data['DEST_HOST'], data.get('DEST_USER', ''), data.get('DEST_PASS', ''))
            data['DEST_HOST'] = conn['host']
            if conn['user']: data['DEST_USER'] = conn['user']
            if conn['pass']: data['DEST_PASS'] = conn['pass']

    # Parse connection string for psql_psql
    if mtype == "psql_psql":
        if 'DB_HOST' in data:
            conn = parse_connection_string(data['DB_HOST'], data.get('DB_USER', ''), data.get('DB_PASS', ''))
            data['DB_HOST'] = conn['host']
            if conn['user']: data['DB_USER'] = conn['user']
            if conn['pass']: data['DB_PASS'] = conn['pass']
            if conn['db']: data['DB_NAME'] = conn['db']
        if 'DEST_HOST' in data:
            conn = parse_connection_string(data['DEST_HOST'], data.get('DEST_USER', ''), data.get('DEST_PASS', ''))
            data['DEST_HOST'] = conn['host']
            if conn['user']: data['DEST_USER'] = conn['user']
            if conn['pass']: data['DEST_PASS'] = conn['pass']
            if conn['db']: data['DEST_NAME'] = conn['db']

    env = os.environ.copy()
    for k, v in data.items():
        env[k] = ",".join(v) if isinstance(v, list) else str(v)

    progress_file = MIGRATORS[mtype]["progress"]
    with open(progress_file, "w") as f:
        json.dump({"percent": 0, "message": "بانتظار البدء...", "status": "idle"}, f)

    subprocess.Popen([sys.executable, MIGRATORS[mtype]["script"]], env=env)

    return jsonify({"status": "started", "type": mtype})

# =========================
# PROGRESS
# =========================
@app.route("/api/progress/<mtype>")
def progress(mtype):
    if mtype not in MIGRATORS:
        return jsonify({"error": "Invalid type"}), 400

    try:
        with open(MIGRATORS[mtype]["progress"]) as f:
            return jsonify(json.load(f))
    except:
        return jsonify({"percent": 0, "message": "بانتظار البدء...", "status": "waiting"})

# =========================
# MAIN
# =========================
if __name__ == "__main__":
    app.run(host="0.0.0.0", port=int(os.getenv("PORT", 8001)))