from __future__ import annotations

import base64
import json
from dataclasses import dataclass
from typing import Any, Iterable, Optional

import requests


@dataclass(frozen=True)
class OcrBox:
    # 4 个顶点坐标（相对截图图片坐标系）
    points: tuple[tuple[int, int], tuple[int, int], tuple[int, int], tuple[int, int]]

    def center(self) -> tuple[int, int]:
        xs = [p[0] for p in self.points]
        ys = [p[1] for p in self.points]
        return (int(sum(xs) / 4), int(sum(ys) / 4))


@dataclass(frozen=True)
class OcrItem:
    text: str
    box: OcrBox


class UmiClient:
    """
    调用 Umi-OCR 的 HTTP API，并将 data_format=dict 的返回解析为 text+box。
    """

    def __init__(self, url: str = "http://127.0.0.1:1224/api/ocr", timeout_s: float = 15.0) -> None:
        self.url = url
        self.timeout_s = timeout_s

    def check_service(self) -> None:
        """
        Umi-OCR 没有稳定的 healthz 文档接口，这里用一次轻量请求做连通性检测。
        只要能建立连接并返回 JSON（即使是业务错误），就认为服务已启动。
        """
        try:
            r = requests.post(self.url, json={"base64": "", "options": {"data_format": "dict"}}, timeout=3)
            _ = r.text  # 触发实际请求
        except requests.RequestException as e:
            raise RuntimeError(f"无法连接 Umi-OCR 服务：{self.url}。请先在 Umi-OCR 中开启 HTTP 服务。") from e

    def ocr_bytes(self, image_bytes: bytes) -> list[OcrItem]:
        img64 = base64.b64encode(image_bytes).decode("utf-8")
        payload = {"base64": img64, "options": {"data_format": "dict"}}
        resp = requests.post(self.url, json=payload, timeout=self.timeout_s)
        resp.raise_for_status()
        data = resp.json()
        return self._parse_umi_dict(data)

    def _parse_umi_dict(self, data: dict[str, Any]) -> list[OcrItem]:
        # 兼容：当返回不是 dict 时直接报错，方便定位
        if not isinstance(data, dict):
            raise ValueError(f"Umi-OCR 返回非 JSON 对象：{type(data)}")

        items: list[OcrItem] = []
        data_list = data.get("data", [])
        if not isinstance(data_list, list):
            raise ValueError(f"Umi-OCR 返回 data 字段不是 list：{json.dumps(data, ensure_ascii=False)[:500]}")

        for it in data_list:
            if not isinstance(it, dict):
                continue
            text = str(it.get("text", "")).strip()
            box = it.get("box")
            pts = _coerce_box_points(box)
            if not text or pts is None:
                continue
            items.append(OcrItem(text=text, box=OcrBox(points=pts)))
        return items

    def find_text(
        self,
        target_name: str,
        items: Iterable[OcrItem],
        *,
        exact: bool = True,
        case_sensitive: bool = False,
    ) -> Optional[tuple[int, int]]:
        """
        在给定 OCR items 中查找目标文字，返回其在截图坐标系下的中心点 (x, y)。
        """
        t = target_name if case_sensitive else target_name.lower()
        for item in items:
            s = item.text if case_sensitive else item.text.lower()
            ok = (s == t) if exact else (t in s)
            if ok:
                return item.box.center()
        return None


def _coerce_box_points(box: Any) -> Optional[tuple[tuple[int, int], tuple[int, int], tuple[int, int], tuple[int, int]]]:
    """
    Umi-OCR 的 box 在 data_format=dict 下通常是 4 个点：
    [[x1,y1],[x2,y2],[x3,y3],[x4,y4]]
    """
    if not (isinstance(box, list) and len(box) == 4):
        return None
    pts: list[tuple[int, int]] = []
    for p in box:
        if not (isinstance(p, (list, tuple)) and len(p) == 2):
            return None
        pts.append((int(p[0]), int(p[1])))
    return (pts[0], pts[1], pts[2], pts[3])