"""审批展示模板 — 可自定义的审批信息展示格式"""

from __future__ import annotations

import html as _html
import logging
import re
from dataclasses import dataclass
from enum import StrEnum

from yuxi.channel.protocols import ApprovalAction, ApprovalDecision, ApprovalRequest, ApprovalResult

logger = logging.getLogger(__name__)

_MD_ESCAPE_RE = re.compile(r"([\\`*_{}\[\]()#+\-.!])")


class TemplateStyle(StrEnum):
    PLAIN = "plain"
    MARKDOWN = "markdown"
    HTML = "html"


@dataclass
class ApprovalTemplateConfig:
    title: str = "审批请求"
    show_request_id: bool = True
    show_action: bool = True
    show_description: bool = True
    show_initiator: bool = True
    show_expiry: bool = True
    style: TemplateStyle = TemplateStyle.PLAIN

    approve_label: str = "批准"
    deny_label: str = "拒绝"
    timeout_minutes: int = 5


_DEFAULT_CONFIG = ApprovalTemplateConfig()


class ApprovalTemplateRenderer:
    def __init__(self, config: ApprovalTemplateConfig | None = None):
        self._config = config or _DEFAULT_CONFIG

    @property
    def config(self) -> ApprovalTemplateConfig:
        return self._config

    def render_request(self, request: ApprovalRequest) -> str:
        cfg = self._config
        lines: list[str] = [f"🔐 {self._bold(cfg.title)}"]

        if cfg.show_request_id:
            lines.append(f"请求 ID: {self._code(request.id)}")
        if cfg.show_action:
            lines.append(f"操作类型: {_action_label(request.action)}")
        if cfg.show_description:
            lines.append(f"描述: {self._escape(request.description)}")
        if cfg.show_initiator:
            lines.append(f"发起人: {self._escape(request.initiator_peer_id)}")
        if cfg.show_expiry and cfg.timeout_minutes > 0:
            lines.append(f"请在 {cfg.timeout_minutes} 分钟内回复")

        lines.append("")
        lines.append(f"回复「{self._bold(cfg.approve_label)}」或「{self._bold(cfg.deny_label)}」做出决定")
        return "\n".join(lines)

    def render_result(self, result: ApprovalResult, request: ApprovalRequest | None = None) -> str:
        if result.decision == ApprovalDecision.APPROVED:
            icon = "✅"
            text = "审批已通过"
        elif result.decision == ApprovalDecision.DENIED:
            icon = "❌"
            text = "审批已拒绝"
        elif result.decision == ApprovalDecision.CANCELLED:
            icon = "🚫"
            text = "审批已取消"
        elif result.decision == ApprovalDecision.EXPIRED:
            icon = "⏰"
            text = "审批已过期"
        else:
            icon = "❓"
            text = "审批状态未知"

        lines = [f"{icon} {self._bold(text)}"]
        lines.append(f"请求 ID: {self._code(result.request_id)}")
        if result.reason:
            lines.append(f"原因: {self._escape(result.reason)}")
        if result.decided_by:
            lines.append(f"决定人: {self._escape(result.decided_by)}")
        return "\n".join(lines)

    def render_expiry_warning(self, request: ApprovalRequest, remaining_seconds: int) -> str:
        request_id = self._code(request.id)
        if remaining_seconds <= 0:
            return f"⏳ 审批请求 {request_id} 已过期。"
        if remaining_seconds < 60:
            return f"⏳ 审批请求 {request_id} 将在 {remaining_seconds} 秒后过期，请尽快处理。"
        minutes = remaining_seconds // 60
        return f"⏳ 审批请求 {request_id} 将在 {minutes} 分钟后过期，请尽快处理。"

    def _bold(self, text: str) -> str:
        style = self._config.style
        if style == TemplateStyle.MARKDOWN:
            return f"**{text}**"
        elif style == TemplateStyle.HTML:
            return f"<b>{_html.escape(text)}</b>"
        return text

    def _code(self, text: str) -> str:
        style = self._config.style
        if style == TemplateStyle.MARKDOWN:
            return f"`{text}`"
        elif style == TemplateStyle.HTML:
            return f"<code>{_html.escape(text)}</code>"
        return f"'{text}'"

    def _escape(self, text: str) -> str:
        style = self._config.style
        if style == TemplateStyle.HTML:
            return _html.escape(text)
        elif style == TemplateStyle.MARKDOWN:
            return _MD_ESCAPE_RE.sub(r"\\\1", text)
        return text


def _action_label(action: ApprovalAction) -> str:
    labels: dict[ApprovalAction, str] = {
        ApprovalAction.APPROVE_EXEC: "执行操作",
        ApprovalAction.APPROVE_READ: "读取操作",
    }
    return labels.get(action, action.value)


_renderer_cache: dict[str, ApprovalTemplateRenderer] = {}


def get_template_renderer(style: str = "default") -> ApprovalTemplateRenderer:
    if style not in _renderer_cache:
        if style == "default":
            _renderer_cache[style] = ApprovalTemplateRenderer()
        elif style == "compact":
            _renderer_cache[style] = ApprovalTemplateRenderer(
                ApprovalTemplateConfig(
                    title="审批",
                    show_request_id=False,
                    show_action=False,
                    show_initiator=False,
                    show_expiry=False,
                )
            )
        elif style == "detailed":
            _renderer_cache[style] = ApprovalTemplateRenderer(
                ApprovalTemplateConfig(
                    title="操作审批请求",
                    style=TemplateStyle.MARKDOWN,
                    timeout_minutes=10,
                )
            )
        else:
            logger.warning("未知模板风格 '%s'，使用默认配置", style)
            _renderer_cache[style] = ApprovalTemplateRenderer()
    return _renderer_cache[style]