from __future__ import annotations

import hashlib
import hmac
import json
import re
from typing import Any


def sanitize_action_id(action_id: str) -> str:
    return re.sub(r"[-_]", "", action_id)


def build_button_attachment(
    title: str,
    text: str,
    buttons: list[dict[str, str]],
    fallback: str = "",
    color: str = "",
    callback_id: str = "",
) -> dict[str, Any]:
    """构建 Mattermost Interactive Button attachment。"""
    actions = []
    for i, btn in enumerate(buttons):
        btn_id = sanitize_action_id(btn.get("id", f"btn_{i}"))
        actions.append(
            {
                "id": btn_id,
                "name": btn.get("name", f"选择 {i + 1}"),
                "integration": {
                    "url": btn.get("callback_url", ""),
                    "context": {
                        "action": btn.get("action", ""),
                        "button_id": btn_id,
                        "callback_id": sanitize_action_id(callback_id),
                        "value": btn.get("value", ""),
                    },
                },
                "type": "button",
                "text": btn.get("text", f"Button {i + 1}"),
                "style": btn.get("style", ""),
            }
        )

    return {
        "fallback": fallback or title,
        "title": title,
        "text": text,
        "color": color or "",
        "callback_id": callback_id,
        "actions": actions,
    }


def build_select_attachment(
    title: str,
    text: str,
    options: list[dict[str, str]],
    select_name: str = "selection",
    callback_id: str = "",
) -> dict[str, Any]:
    """构建 Mattermost Select dropdown attachment。"""
    select_options = []
    for opt in options:
        select_options.append(
            {
                "text": opt.get("text", ""),
                "value": opt.get("value", ""),
            }
        )

    return {
        "fallback": title,
        "title": title,
        "text": text,
        "callback_id": sanitize_action_id(callback_id),
        "actions": [
            {
                "id": sanitize_action_id(select_name),
                "name": select_name,
                "integration": {
                    "url": "",
                    "context": {"action": select_name, "callback_id": sanitize_action_id(callback_id)},
                },
                "type": "select",
                "options": select_options,
            },
        ],
    }


def parse_interaction_context(data: dict) -> dict:
    """解析交互回调 context。"""
    context = data.get("context", {})
    if isinstance(context, str):
        try:
            context = json.loads(context)
        except json.JSONDecodeError:
            context = {}
    return context


def verify_hmac_signature(payload: bytes, signature: str, secret: str) -> bool:
    """验证 HMAC 签名。"""
    if not signature or not secret:
        return False
    expected = hmac.new(
        secret.encode(),
        payload,
        hashlib.sha256,
    ).hexdigest()
    return hmac.compare_digest(expected, signature)


def build_button_props_pipeline(
    channel_id: str,
    buttons: list[dict[str, Any]],
    flatten: bool = True,
) -> list[dict[str, Any]]:
    result: list[dict[str, Any]] = []
    for item in buttons:
        if flatten and isinstance(item, list):
            for nested in item:
                _bind_channel_to_button(nested, channel_id)
                result.append(nested)
        else:
            _bind_channel_to_button(item, channel_id)
            result.append(item)
    return result


def _bind_channel_to_button(button: dict[str, Any], channel_id: str) -> None:
    integration = button.get("integration", {})
    if integration:
        context = integration.get("context", {})
        if context:
            context["channel_id"] = channel_id
            integration["context"] = context
            button["integration"] = integration