import "./CharsetConverterMobile.css";
import React, { useState, useRef } from "react";
import { Button, Select } from "antd";
import { message } from "@/utils/message";
import {
  ArrowLeftOutlined,
  SwapOutlined,
  CopyOutlined,
  DeleteOutlined,
  DownloadOutlined,
  UploadOutlined,
} from "@ant-design/icons";
import { useNavigate } from "react-router-dom";
import ToolFavoriteButton from "@/components/ToolFavoriteButton/ToolFavoriteButton";
import {
  CHAR_ENCODING_OPTIONS,
  decodeBytes,
  encodeText,
  detectEncoding,
  fileToBytes,
  downloadBytes,
  normalizeEncoding,
} from "@/utils/charEncoding";

const ENCODING_OPTIONS = CHAR_ENCODING_OPTIONS.map((opt) => ({
  value: opt.value,
  label: opt.label,
}));

const sourceOptions = [
  { value: "auto", label: "自动检测" },
  ...ENCODING_OPTIONS,
];

const CharsetConverterMobile: React.FC = () => {
  const navigate = useNavigate();
  const [inputText, setInputText] = useState("");
  const [outputText, setOutputText] = useState("");
  const [sourceEncoding, setSourceEncoding] = useState("auto");
  const [targetEncoding, setTargetEncoding] = useState("utf-8");
  const [fileInfo, setFileInfo] = useState<{ name: string; bytes: Uint8Array } | null>(null);
  const [convertedBytes, setConvertedBytes] = useState<Uint8Array | null>(null);
  const fileInputRef = useRef<HTMLInputElement>(null);

  const handleFile = async (file: File) => {
    try {
      const bytes = await fileToBytes(file);
      setFileInfo({ name: file.name, bytes });
      const detected = detectEncoding(bytes);
      setInputText(decodeBytes(bytes, detected.encoding));
      setSourceEncoding(detected.encoding);
      setOutputText("");
      setConvertedBytes(null);
      message.success("文件已加载");
    } catch (e: any) {
      message.error(`读取文件失败: ${e.message}`);
    }
  };

  const handleConvert = () => {
    if (!fileInfo && !inputText.trim()) {
      message.warning("请先上传文件或输入文本");
      return;
    }

    try {
      let srcBytes: Uint8Array;
      let src: string;

      if (fileInfo) {
        srcBytes = fileInfo.bytes;
        src = sourceEncoding === "auto" ? detectEncoding(fileInfo.bytes).encoding : sourceEncoding;
      } else {
        src = normalizeEncoding(sourceEncoding);
        srcBytes = encodeText(inputText, src);
      }

      const decoded = decodeBytes(srcBytes, src);
      const outBytes = encodeText(decoded, targetEncoding);
      setOutputText(decoded);
      setConvertedBytes(outBytes);
      message.success("转换成功");
    } catch (e: any) {
      message.error(`转换错误: ${e.message}`);
    }
  };

  const handleSwap = () => {
    const tmp = sourceEncoding;
    setSourceEncoding(targetEncoding);
    setTargetEncoding(tmp);
    const tmpText = inputText;
    setInputText(outputText);
    setOutputText(tmpText);
  };

  const handleClear = () => {
    setInputText("");
    setOutputText("");
    setFileInfo(null);
    setConvertedBytes(null);
    setSourceEncoding("auto");
    setTargetEncoding("utf-8");
    if (fileInputRef.current) {
      fileInputRef.current.value = "";
    }
  };

  const handleCopy = () => {
    if (!outputText) {
      message.warning("没有可复制的内容");
      return;
    }
    navigator.clipboard.writeText(outputText).then(() => {
      message.success("已复制到剪贴板");
    });
  };

  const handleDownload = () => {
    if (!convertedBytes || convertedBytes.length === 0) {
      message.warning("请先进行转换");
      return;
    }
    const baseName = fileInfo?.name
      ? fileInfo.name.replace(/\.[^.]+$/, "")
      : "converted";
    const extMatch = fileInfo?.name?.match(/\.[^.]+$/);
    const ext = extMatch ? extMatch[0] : ".txt";
    downloadBytes(convertedBytes, `${baseName}.${targetEncoding}${ext}`, targetEncoding);
  };

  return (
    <div className="cc-mobile-page">
      <div className="cc-mobile-header">
        <Button
          type="text"
          icon={<ArrowLeftOutlined />}
          onClick={() => navigate("/utility")}
        />
        <div className="cc-mobile-header-title-row">
          <span>编码转换</span>
          <ToolFavoriteButton urlPath="/utility/charset-converter" variant="hero" />
        </div>
        <span />
      </div>

      <div className="cc-mobile-content">
        <div className="cc-mobile-actions">
          <button className="cc-mobile-action-btn" onClick={handleCopy}>
            <CopyOutlined /> <span>复制</span>
          </button>
          <button className="cc-mobile-action-btn" onClick={handleDownload}>
            <DownloadOutlined /> <span>下载</span>
          </button>
          <button className="cc-mobile-action-btn" onClick={handleSwap}>
            <SwapOutlined /> <span>交换</span>
          </button>
          <button className="cc-mobile-action-btn cc-mobile-action-btn--danger" onClick={handleClear}>
            <DeleteOutlined /> <span>清空</span>
          </button>
        </div>

        <div className="cc-mobile-select-area">
          <Select
            value={sourceEncoding}
            onChange={setSourceEncoding}
            options={sourceOptions}
            style={{ width: "100%" }}
            size="large"
            showSearch
            optionFilterProp="label"
          />
          <div className="cc-mobile-swap-row">
            <SwapOutlined style={{ color: "#1677ff" }} />
          </div>
          <Select
            value={targetEncoding}
            onChange={setTargetEncoding}
            options={ENCODING_OPTIONS}
            style={{ width: "100%" }}
            size="large"
            showSearch
            optionFilterProp="label"
          />
        </div>

        <input
          type="file"
          ref={fileInputRef}
          style={{ display: "none" }}
          accept=".txt,.csv,.json,.xml,.html,.htm,.md,.log,.ini,.conf"
          onChange={(e) => {
            const f = e.target.files?.[0];
            if (f) handleFile(f);
          }}
        />

        <div className="cc-mobile-upload" onClick={() => fileInputRef.current?.click()}>
          <UploadOutlined style={{ fontSize: 22, color: "#1677ff" }} />
          <span>上传文本文件</span>
        </div>

        <textarea
          className="cc-mobile-textarea"
          value={inputText}
          onChange={(e) => setInputText(e.target.value)}
          placeholder="在此输入或粘贴文本..."
          rows={8}
          spellCheck={false}
        />

        <Button
          type="primary"
          icon={<SwapOutlined />}
          onClick={handleConvert}
          block
        >
          转换
        </Button>

        <div className="cc-mobile-output">
          {outputText || "结果将显示在这里..."}
        </div>
      </div>
    </div>
  );
};

export default CharsetConverterMobile;