import os
from typing import Dict
from functools import wraps

from dotenv import load_dotenv
from flask import Flask, jsonify, render_template, request, redirect, url_for, session

from aws_service import (
    AWSOperationError,
    ConfigError,
    AccountConfig,
    load_account_configs,
    replace_instance_ip,
)
from db import (
    add_replacement_history,
    get_account_by_ip,
    get_replacement_history,
    get_history_by_ip_or_group,
    get_history_chains,
    get_server_spec,
    init_db,
    load_disallowed_ips,
    update_ip_account_mapping,
    upsert_server_spec,
)


load_dotenv()

app = Flask(__name__)
app.secret_key = os.getenv("SECRET_KEY", "please-change-me")

APP_USER = os.getenv("APP_USER", "")
APP_PASSWORD = os.getenv("APP_PASSWORD", "")


def login_required(fn):
    @wraps(fn)
    def wrapper(*args, **kwargs):
        if not session.get("authed"):
            return redirect(url_for("login", next=request.path))
        return fn(*args, **kwargs)

    return wrapper


def load_configs() -> Dict[str, AccountConfig]:
    config_path = os.getenv("AWS_CONFIG_PATH", "config/accounts.yaml")
    return load_account_configs(config_path)


try:
    account_configs = load_configs()
    init_error = ""
except ConfigError as exc:
    account_configs = {}
    init_error = str(exc)

retry_limit = int(os.getenv("IP_RETRY_LIMIT", "5"))

try:
    init_db()
    db_error = ""
except Exception as exc:  # noqa: BLE001 - surface DB connection issues to UI
    db_error = f"数据库初始化失败: {exc}"


@app.route("/", methods=["GET"])
@login_required
def index():
    if init_error or db_error:
        return render_template("index.html", accounts=[], init_error=init_error or db_error)
    return render_template("index.html", accounts=account_configs.values(), init_error="")


@app.route("/login", methods=["GET", "POST"])
def login():
    if session.get("authed"):
        return redirect(url_for("index"))
    error = ""
    next_url = request.args.get("next", "/")
    if request.method == "POST":
        username = request.form.get("username", "").strip()
        password = request.form.get("password", "").strip()
        if username == APP_USER and password == APP_PASSWORD:
            session["authed"] = True
            return redirect(next_url or url_for("index"))
        error = "用户名或密码错误"
    return render_template("login.html", error=error, next_url=next_url)


@app.route("/logout", methods=["POST"])
def logout():
    session.clear()
    return redirect(url_for("login"))


@app.route("/replace_ip", methods=["POST"])
@login_required
def replace_ip():
    if init_error or db_error:
        return jsonify({"error": init_error or db_error}), 500

    ip_to_replace = request.form.get("ip_to_replace", "").strip()

    if not ip_to_replace:
        return jsonify({"error": "请输入要替换的IP"}), 400

    account_name = get_account_by_ip(ip_to_replace)
    if not account_name:
        return jsonify({"error": "数据库中未找到该IP对应的账户映射"}), 400
    if account_name not in account_configs:
        return jsonify({"error": f"账户 {account_name} 未在配置文件中定义"}), 400

    disallowed = load_disallowed_ips()
    fallback_spec = get_server_spec(ip_to_replace)
    account = account_configs[account_name]
    try:
        result = replace_instance_ip(
            ip_to_replace, account, disallowed, retry_limit, fallback_spec=fallback_spec
        )
        spec_used = result.get("spec_used", {}) if isinstance(result, dict) else {}
        # 记录当前 IP 的规格（输入 IP、数据库规格、或从 AWS 读到的规格）
        upsert_server_spec(
            ip_address=ip_to_replace,
            account_name=account_name,
            instance_type=spec_used.get("instance_type"),
            instance_name=spec_used.get("instance_name"),
            volume_type=spec_used.get("root_volume_type"),
            security_group_names=spec_used.get("security_group_names", []),
            security_group_ids=spec_used.get("security_group_ids", []),
            region=spec_used.get("region"),
            subnet_id=spec_used.get("subnet_id"),
            availability_zone=spec_used.get("availability_zone"),
        )
        # 新 IP 同步规格
        upsert_server_spec(
            ip_address=result["new_ip"],
            account_name=account_name,
            instance_type=spec_used.get("instance_type"),
            instance_name=spec_used.get("instance_name"),
            volume_type=spec_used.get("root_volume_type"),
            security_group_names=spec_used.get("security_group_names", []),
            security_group_ids=spec_used.get("security_group_ids", []),
            region=spec_used.get("region"),
            subnet_id=spec_used.get("subnet_id"),
            availability_zone=spec_used.get("availability_zone"),
        )
        update_ip_account_mapping(ip_to_replace, result["new_ip"], account_name)
        add_replacement_history(
            ip_to_replace,
            result["new_ip"],
            account_name,
            None,
            terminated_network_out_mb=result.get("terminated_network_out_mb"),
        )
    except (AWSOperationError, ValueError) as exc:
        return jsonify({"error": str(exc)}), 400

    return jsonify(result), 200


@app.route("/history", methods=["GET"])
@login_required
def history():
    try:
        records = get_replacement_history(limit=100)
    except Exception as exc:  # noqa: BLE001
        return jsonify({"error": f"读取历史失败: {exc}"}), 500
    return jsonify({"items": records})


@app.route("/history/search", methods=["GET"])
@login_required
def history_search():
    ip = request.args.get("ip", "").strip() or None
    group_id = request.args.get("group", "").strip() or None
    try:
        records = get_history_by_ip_or_group(ip, group_id, limit=200)
    except Exception as exc:  # noqa: BLE001
        return jsonify({"error": f"读取历史失败: {exc}"}), 500
    return jsonify({"items": records})


@app.route("/history_page", methods=["GET"])
@login_required
def history_page():
    return render_template("history.html")


@app.route("/history/chains", methods=["GET"])
@login_required
def history_chains():
    ip = request.args.get("ip", "").strip() or None
    group_id = request.args.get("group", "").strip() or None
    try:
        records = get_history_chains(ip=ip, group_id=group_id, limit=500)
    except Exception as exc:  # noqa: BLE001
        return jsonify({"error": f"读取历史失败: {exc}"}), 500
    return jsonify({"items": records})


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5000, debug=True)