"""OpenRouter transport and model configuration. No credentials in UI or logs."""

import json
import os
from urllib.parse import urlsplit

import httpx

API_BASE = "https://openrouter.ai/api/v1"
MODELS = {
    "anthropic/claude-opus-5.5": ("Claude Opus 5.5", "4", "20"),
    "anthropic/claude-sonnet-5.5": ("Claude Sonnet 5.5", "2", "10"),
    "anthropic/claude-fable-5.1": ("Claude Fable 5.1", "10", "50"),
    "deepseek/deepseek-v4.1-flash": ("DeepSeek V4.1 Flash", "0.30", "1.20"),
}
DEFAULT_MODEL = "anthropic/claude-sonnet-5.5"


class RouterError(Exception):
    """A safe, user-facing error without request headers or document content."""


def build_payload(messages: list, model: str, search: bool, max_tokens: int, effort: str) -> dict:
    if model not in MODELS:
        raise RouterError("请选择列表中的模型。")
    if effort not in {"low", "medium", "high", "xhigh", "max"}:
        raise RouterError("无效的推理强度。")
    if not 1024 <= int(max_tokens) <= 32768:
        raise RouterError("输出上限需在 1024–32768 tokens 之间。")
    payload = {
        "model": model, "messages": messages, "stream": True,
        "stream_options": {"include_usage": True}, "max_tokens": int(max_tokens),
        "reasoning": {"effort": effort},
        "provider": {"require_parameters": True},
    }
    if search:
        payload["tools"] = [{"type": "openrouter:web_search", "parameters": {
            "engine": "native", "max_results": 5, "max_total_results": 10,
        }}]
    if any(part.get("type") == "file" for msg in messages
           if isinstance(msg.get("content"), list) for part in msg["content"]):
        payload["plugins"] = [{"id": "file-parser", "pdf": {"engine": "native"}}]
    return payload


def stream_reply(payload: dict):
    """Yield SSE events; never retry a potentially billed request automatically."""
    key = os.environ.get("OPENROUTER_API_KEY", "").strip()
    if not key:
        raise RouterError("请在 Space Settings → Secrets 中设置 OPENROUTER_API_KEY。")
    headers = {"Authorization": f"Bearer {key}", "X-Title": "Hailey AI Agent"}
    try:
        with httpx.Client(timeout=httpx.Timeout(300, connect=20)) as client:
            with client.stream("POST", f"{API_BASE}/chat/completions", headers=headers, json=payload) as response:
                if response.status_code != 200:
                    descriptions = {
                        400: "请求不被接受，请检查文件、上下文长度或模型参数。",
                        401: "API Key 无效或已失效。", 402: "OpenRouter 余额或额度不足。",
                        403: "账号或供应商拒绝访问，请检查权限与地区设置。",
                        404: "模型或可用供应商暂不存在。", 413: "请求文件过大，请减少附件。",
                        429: "请求频率或额度受限，请稍后重试。",
                    }
                    raise RouterError(f"OpenRouter HTTP {response.status_code}：" +
                                      descriptions.get(response.status_code, "服务暂时不可用，请稍后重试。"))
                ended = False
                for line in response.iter_lines():
                    if not line.startswith("data:"):
                        continue
                    raw = line[5:].strip()
                    if raw == "[DONE]":
                        ended = True
                        break
                    if not raw:
                        continue
                    event = json.loads(raw)
                    if event.get("error"):
                        raise RouterError("上游模型在生成过程中报错。请在 OpenRouter Activity 查看本次请求。")
                    yield event
                if not ended:
                    raise RouterError("连接提前关闭，回复可能不完整；本次请求可能已产生费用。")
    except httpx.TimeoutException:
        raise RouterError("请求超时；本次请求可能已产生费用，请检查 OpenRouter Activity 后再重试。") from None
    except (httpx.HTTPError, ValueError):
        raise RouterError("OpenRouter 连接或响应异常，请稍后重试。") from None


def citations_markdown(annotations: list) -> str:
    urls = []
    for annotation in annotations:
        if annotation.get("type") != "url_citation":
            continue
        item = annotation.get("url_citation", {})
        url = item.get("url", "")
        if urlsplit(url).scheme not in {"http", "https"} or url in urls:
            continue
        urls.append(url)
    if not urls:
        return ""
    # Fixed labels avoid injecting untrusted titles into Markdown.
    return "\n\n---\n**参考来源**\n" + "\n".join(
        f"- [来源 {i}](<{url.replace('>', '%3E').replace('<', '%3C')}>)" for i, url in enumerate(urls, 1)
    )


def usage_summary(usage: dict, model: str) -> str:
    parts = [MODELS[model][0]]
    if usage:
        parts.extend([f"输入 {usage.get('prompt_tokens', 0):,} tokens",
                      f"输出 {usage.get('completion_tokens', 0):,} tokens"])
        if usage.get("cost") is not None:
            parts.append(f"本次 API 返回费用 ${float(usage['cost']):.6f}")
        else:
            parts.append("本次费用未返回，请查看 OpenRouter Activity")
        searches = usage.get("server_tool_use", {}).get("web_search_requests")
        if searches is not None:
            parts.append(f"联网搜索 {searches} 次")
    else:
        parts.append("用量未返回，请查看 OpenRouter Activity")
    return " · ".join(parts)