"use client";

import React, { useRef, useState } from "react";
import { Box, Button, Paper, Stack, Tab, Tabs, TextField, Typography } from "@mui/material";
import { NEXT_PUBLIC_API_URL } from "@/config/api";
import { clientAuthFetch } from "@/app/utils/clientAuthFetch";

interface TabPanelProps {
  children?: React.ReactNode;
  index: number;
  value: number;
}

function TabPanel(props: TabPanelProps) {
  const { children, value, index, ...other } = props;
  return (
    <div
      role="tabpanel"
      hidden={value !== index}
      id={`m18syn-tabpanel-${index}`}
      aria-labelledby={`m18syn-tab-${index}`}
      {...other}
    >
      {value === index && <Box sx={{ p: 3 }}>{children}</Box>}
    </div>
  );
}

export default function M18SynPage() {
  const [tabValue, setTabValue] = useState(0);

  type SyncResultDto = {
    totalProcessed: number;
    totalSuccess: number;
    totalFail: number;
    query?: string | null;
  };

  type ParsedSyncResult =
    | { kind: "exists"; message: string }
    | { kind: "not_found"; message: string }
    | { kind: "success"; message: string; totalSuccess: number }
    | { kind: "fail"; message: string; totalFail: number }
    | { kind: "mixed"; message: string; totalSuccess: number; totalFail: number }
    | { kind: "raw"; message: string };

  const parseSyncResult = (docName: string, rawText: string): ParsedSyncResult => {
    const text = rawText?.trim() ?? "";
    if (!text) return { kind: "raw", message: "未收到回應" };
    try {
      const obj = JSON.parse(text) as Partial<SyncResultDto>;
      const totalSuccess = Number(obj.totalSuccess ?? 0);
      const totalFail = Number(obj.totalFail ?? 0);
      const totalProcessed = Number(obj.totalProcessed ?? 0);
      const query = (obj.query ?? "").toString();

      // newOnly skip message from backend
      if (query.includes("skipped") && query.includes("already exists")) {
        return { kind: "exists", message: `${docName}已存在系統` };
      }

      // "not found in M18" (sync-by-code returns processed=1, fail=1)
      if (
        docName === "送貨訂單" &&
        totalProcessed === 1 &&
        totalSuccess === 0 &&
        totalFail === 1 &&
        query.includes("code=equal=")
      ) {
        return { kind: "not_found", message: `在M18找不到${docName}` };
      }

      if (totalSuccess > 0 && totalFail === 0) {
        return { kind: "success", totalSuccess, message: `成功同步: ${totalSuccess}張${docName}` };
      }
      if (totalSuccess === 0 && totalFail > 0) {
        return { kind: "fail", totalFail, message: `失敗: 無法同步${docName}` };
      }
      return { kind: "mixed", totalSuccess, totalFail, message: `完成: 成功 ${totalSuccess} / 失敗 ${totalFail} (${docName})` };
    } catch {
      // Non-JSON error body or plain text
      return { kind: "raw", message: text };
    }
  };

  const formatSyncResultText = (docName: string, rawText: string): string => parseSyncResult(docName, rawText).message;

  const [m18PoCode, setM18PoCode] = useState("");
  const [isSyncingM18Po, setIsSyncingM18Po] = useState(false);
  const [m18PoSyncResult, setM18PoSyncResult] = useState<string>("");
  const m18PoInFlightRef = useRef(false);

  const [m18DoCode, setM18DoCode] = useState("");
  const [isSyncingM18Do, setIsSyncingM18Do] = useState(false);
  const [m18DoSyncResult, setM18DoSyncResult] = useState<string>("");
  const m18DoInFlightRef = useRef(false);

  const [m18DoExtraCode, setM18DoExtraCode] = useState("");
  const [isSyncingM18DoExtra, setIsSyncingM18DoExtra] = useState(false);
  const [m18DoExtraSyncResult, setM18DoExtraSyncResult] = useState<string>("");
  const m18DoExtraInFlightRef = useRef(false);

  const [m18ProductCode, setM18ProductCode] = useState("");
  const [isSyncingM18Product, setIsSyncingM18Product] = useState(false);
  const [m18ProductSyncResult, setM18ProductSyncResult] = useState<string>("");
  const m18ProductInFlightRef = useRef(false);

  const handleSyncM18PoByCode = async () => {
    if (m18PoInFlightRef.current) return;
    if (!m18PoCode.trim()) {
      alert("Please enter PO code.");
      return;
    }
    m18PoInFlightRef.current = true;
    setIsSyncingM18Po(true);
    setM18PoSyncResult("");
    try {
      const response = await clientAuthFetch(
        `${NEXT_PUBLIC_API_URL}/m18/test/po-by-code?code=${encodeURIComponent(m18PoCode.trim())}`,
        { method: "GET" },
      );
      if (response.status === 401 || response.status === 403) return;
      const text = await response.text();
      setM18PoSyncResult(formatSyncResultText("採購單", text));
      if (!response.ok) {
        alert(`Sync failed: ${response.status}`);
      }
    } catch (e) {
      console.error("M18 PO Sync By Code Error:", e);
      alert("M18 PO sync failed. Check console/network.");
    } finally {
      setIsSyncingM18Po(false);
      m18PoInFlightRef.current = false;
    }
  };

  const handleSyncM18DoByCode = async () => {
    if (m18DoInFlightRef.current) return;
    if (!m18DoCode.trim()) {
      alert("Please enter DO / shop PO code.");
      return;
    }
    m18DoInFlightRef.current = true;
    setIsSyncingM18Do(true);
    setM18DoSyncResult("");
    try {
      const response = await clientAuthFetch(
        `${NEXT_PUBLIC_API_URL}/m18/test/do-by-code?code=${encodeURIComponent(m18DoCode.trim())}`,
        { method: "GET" },
      );
      if (response.status === 401 || response.status === 403) return;
      const text = await response.text();
      setM18DoSyncResult(formatSyncResultText("送貨訂單", text));
      if (!response.ok) {
        alert(`Sync failed: ${response.status}`);
      }
    } catch (e) {
      console.error("M18 DO Sync By Code Error:", e);
      alert("M18 DO sync failed. Check console/network.");
    } finally {
      setIsSyncingM18Do(false);
      m18DoInFlightRef.current = false;
    }
  };

  /** DO（加單）：手動按 code 同步，並寫入本地 isExtra=true（可輸入多個 code，用逗號或換行分隔） */
  const handleSyncM18DoExtraByCode = async () => {
    if (m18DoExtraInFlightRef.current) return;
    const raw = m18DoExtraCode.trim();
    if (!raw) {
      alert("Please enter DO / shop PO code(s) (加單).");
      return;
    }
    const codes = raw
      .split(/[\n,]+/g)
      .map((s) => s.trim())
      .filter(Boolean);
    if (codes.length === 0) {
      alert("Please enter at least one code.");
      return;
    }
    m18DoExtraInFlightRef.current = true;
    setIsSyncingM18DoExtra(true);
    setM18DoExtraSyncResult("");
    try {
      const outputs: string[] = [];
      const okCodes: string[] = [];
      const existsCodes: string[] = [];
      const notFoundCodes: string[] = [];
      const otherFailCodes: string[] = [];
      for (const code of codes) {
        const response = await clientAuthFetch(
          `${NEXT_PUBLIC_API_URL}/m18/test/do-by-code-extra?code=${encodeURIComponent(code)}`,
          { method: "GET" },
        );
        if (response.status === 401 || response.status === 403) return;
        const text = await response.text();
        const parsed = parseSyncResult("送貨訂單", text || "");
        if (parsed.kind === "success") okCodes.push(code);
        else if (parsed.kind === "exists") existsCodes.push(code);
        else if (parsed.kind === "not_found") notFoundCodes.push(code);
        else otherFailCodes.push(code);

        const perCodeMsg =
          parsed.kind === "success" ? "成功同步" :
          parsed.kind === "exists" ? `失敗: ${parsed.message}` :
          parsed.kind === "not_found" ? parsed.message :
          parsed.message;
        outputs.push(`${code}: ${perCodeMsg}${response.ok ? "" : ` (HTTP ${response.status})`}`);
      }

      // Summary
      outputs.push("");
      outputs.push(`共${okCodes.length}張送貨訂單成功`);
      if (notFoundCodes.length > 0) outputs.push(`共${notFoundCodes.length}張在M18找不到訂單 (${notFoundCodes.join(", ")})`);
      if (existsCodes.length > 0) outputs.push(`共${existsCodes.length}張訂單已存在系統 (${existsCodes.join(", ")})`);
      if (otherFailCodes.length > 0) outputs.push(`共${otherFailCodes.length}張同步失敗 (${otherFailCodes.join(", ")})`);

      setM18DoExtraSyncResult(outputs.join("\n"));
    } catch (e) {
      console.error("M18 DO (加單) Sync By Code Error:", e);
      alert("M18 DO (加單) sync failed. Check console/network.");
    } finally {
      setIsSyncingM18DoExtra(false);
      m18DoExtraInFlightRef.current = false;
    }
  };

  const handleSyncM18ProductByCode = async () => {
    if (m18ProductInFlightRef.current) return;
    if (!m18ProductCode.trim()) {
      alert("Please enter M18 item / product code.");
      return;
    }
    m18ProductInFlightRef.current = true;
    setIsSyncingM18Product(true);
    setM18ProductSyncResult("");
    try {
      const response = await clientAuthFetch(
        `${NEXT_PUBLIC_API_URL}/m18/test/product-by-code?code=${encodeURIComponent(m18ProductCode.trim())}`,
        { method: "GET" },
      );
      if (response.status === 401 || response.status === 403) return;
      const text = await response.text();
      setM18ProductSyncResult(formatSyncResultText("產品", text));
      if (!response.ok) {
        alert(`Sync failed: ${response.status}`);
      }
    } catch (e) {
      console.error("M18 Product Sync By Code Error:", e);
      alert("M18 product sync failed. Check console/network.");
    } finally {
      setIsSyncingM18Product(false);
      m18ProductInFlightRef.current = false;
    }
  };

  const Section = ({ title, children }: { title: string; children?: React.ReactNode }) => (
    <Paper sx={{ p: 3, minHeight: "450px", display: "flex", flexDirection: "column" }}>
      <Typography variant="h5" gutterBottom color="primary" sx={{ borderBottom: "2px solid #f0f0f0", pb: 1, mb: 2 }}>
        {title}
      </Typography>
      {children || <Typography color="textSecondary" sx={{ m: "auto" }}>Waiting for implementation...</Typography>}
    </Paper>
  );

  return (
    <Box sx={{ p: 4 }}>
      <Typography variant="h4" sx={{ mb: 4, fontWeight: "bold" }}>
        M18 Sync (by code)
      </Typography>
      <Typography variant="body2" color="textSecondary" sx={{ mb: 2 }}>
        ADMIN only. Sync Purchase Order, Delivery Order, or product/material from M18 using document or item code.
      </Typography>

      <Tabs value={tabValue} onChange={(_, v) => setTabValue(v)} aria-label="M18 sync by code" centered variant="fullWidth">
        <Tab label="1. 採購單" id="m18syn-tab-0" />
        <Tab label="2. 送貨訂單" id="m18syn-tab-1" />
        <Tab label="3. 送貨訂單 (加單)" id="m18syn-tab-2" />
        <Tab label="4. Product" id="m18syn-tab-3" />
      </Tabs>

      <TabPanel value={tabValue} index={0}>
        <Section title="M18 採購單 — sync by code">
          <Stack direction="row" spacing={2} sx={{ mb: 2, alignItems: "center" }}>
            <TextField
              size="small"
              label="PO Code"
              value={m18PoCode}
              onChange={(e) => setM18PoCode(e.target.value)}
              placeholder="e.g. PFP002PO26030341"
              sx={{ minWidth: 320 }}
            />
            <Button variant="contained" color="primary" onClick={handleSyncM18PoByCode} disabled={isSyncingM18Po}>
              {isSyncingM18Po ? "Syncing..." : "Sync PO from M18"}
            </Button>
          </Stack>
          {m18PoSyncResult ? (
            <TextField
              fullWidth
              multiline
              minRows={4}
              margin="normal"
              label="Sync Result"
              value={m18PoSyncResult}
              InputProps={{ readOnly: true }}
            />
          ) : null}
        </Section>
      </TabPanel>

      <TabPanel value={tabValue} index={1}>
        <Section title="M18 送貨訂單 — sync by code">
          <Stack direction="row" spacing={2} sx={{ mb: 2, alignItems: "center" }}>
            <TextField
              size="small"
              label="DO / Shop PO Code"
              value={m18DoCode}
              onChange={(e) => setM18DoCode(e.target.value)}
              placeholder="e.g. same document code as M18 shop PO"
              sx={{ minWidth: 320 }}
            />
            <Button variant="contained" color="primary" onClick={handleSyncM18DoByCode} disabled={isSyncingM18Do}>
              {isSyncingM18Do ? "Syncing..." : "Sync DO from M18"}
            </Button>
          </Stack>
          {m18DoSyncResult ? (
            <TextField
              fullWidth
              multiline
              minRows={4}
              margin="normal"
              label="Sync Result"
              value={m18DoSyncResult}
              InputProps={{ readOnly: true }}
            />
          ) : null}
        </Section>
      </TabPanel>

      <TabPanel value={tabValue} index={2}>
        <Section title="M18 送貨訂單 — 加單 (isExtra)">
          <Stack spacing={2} sx={{ mb: 2 }}>
            <TextField
              label="DO / Shop PO Code（加單）"
              value={m18DoExtraCode}
              onChange={(e) => setM18DoExtraCode(e.target.value)}
              placeholder="可輸入多個 code，用逗號或換行分隔"
              fullWidth
              multiline
              minRows={6}
              maxRows={14}
            />
            <Box sx={{ display: "flex", justifyContent: "flex-end" }}>
              <Button
                variant="contained"
                color="primary"
                onClick={handleSyncM18DoExtraByCode}
                disabled={isSyncingM18DoExtra}
              >
                {isSyncingM18DoExtra ? "Syncing..." : "Sync 送貨訂單（加單）from M18"}
              </Button>
            </Box>
          </Stack>
          {m18DoExtraSyncResult ? (
            <TextField
              fullWidth
              multiline
              minRows={4}
              margin="normal"
              label="Sync Result"
              value={m18DoExtraSyncResult}
              InputProps={{ readOnly: true }}
            />
          ) : null}
        </Section>
      </TabPanel>

      <TabPanel value={tabValue} index={3}>
        <Section title="M18 Product / material — sync by code">
          <Stack direction="row" spacing={2} sx={{ mb: 2, alignItems: "center" }}>
            <TextField
              size="small"
              label="Item / product code"
              value={m18ProductCode}
              onChange={(e) => setM18ProductCode(e.target.value)}
              placeholder="e.g. PP1175 (M18 item code)"
              sx={{ minWidth: 320 }}
            />
            <Button
              variant="contained"
              color="primary"
              onClick={handleSyncM18ProductByCode}
              disabled={isSyncingM18Product}
            >
              {isSyncingM18Product ? "Syncing..." : "Sync product from M18"}
            </Button>
          </Stack>
          {m18ProductSyncResult ? (
            <TextField
              fullWidth
              multiline
              minRows={4}
              margin="normal"
              label="Sync Result"
              value={m18ProductSyncResult}
              InputProps={{ readOnly: true }}
            />
          ) : null}
        </Section>
      </TabPanel>

    </Box>
  );
}