import { useState, useEffect, useCallback, useRef } from "react";
import { batchAPI } from "../api/client";
import RecipientInput from "./RecipientInput";
import EmailQueue from "./EmailQueue";
import toast from "react-hot-toast";

export default function BatchProcessor({ currentSubject, currentHtml }) {
    const [batchQueue, setBatchQueue] = useState([]);
    const [batchStats, setBatchStats] = useState({});
    const [batchMode, setBatchMode] = useState("manual");
    const [batchCurrentIdx, setBatchCurrentIdx] = useState(-1);
    const [autoRunning, setAutoRunning] = useState(false);
    const [loading, setLoading] = useState(false);
    const pollRef = useRef(null);

    const refreshBatchStatus = useCallback(async () => {
        try {
            const res = await batchAPI.getQueue();
            setBatchQueue(res.data.queue);
            setBatchStats(res.data.stats);
            setBatchMode(res.data.mode);
            setBatchCurrentIdx(res.data.current_index);
            return res.data;
        } catch (err) {
            console.error("Failed to fetch batch queue", err);
        }
    }, []);

    useEffect(() => {
        refreshBatchStatus();
        const interval = setInterval(refreshBatchStatus, 3000);
        return () => clearInterval(interval);
    }, [refreshBatchStatus]);

    const handleBatchStart = async (profList, mode, delayMin, delayMax) => {
        setLoading(true);
        try {
            await batchAPI.start(profList, mode, delayMin, delayMax);
            toast.success("Batch started!");
            refreshBatchStatus();
        } catch (err) {
            toast.error(err.response?.data?.detail || "Failed to start batch");
        } finally {
            setLoading(false);
        }
    };

    const handleBatchApprove = async (index) => {
        try {
            await batchAPI.send(index);
            toast.success("Email sent!");
            refreshBatchStatus();
        } catch (err) {
            toast.error("Send failed");
        }
    };

    const handleBatchSkip = async (index) => {
        try {
            await batchAPI.skip(index);
            toast.success("Skipped");
            refreshBatchStatus();
        } catch {
            toast.error("Skip failed");
        }
    };

    const handleAutoRun = async () => {
        setAutoRunning(true);
        try {
            await batchAPI.autoRun();
        } catch (err) {
            if (err.name !== "CanceledError") {
                toast.error("Auto-run stopped or failed");
            }
        } finally {
            setAutoRunning(false);
            refreshBatchStatus();
        }
    };

    const handleStopAuto = async () => {
        try {
            await batchAPI.stop();
            setAutoRunning(false);
            toast.success("Stopped");
        } catch {
            toast.error("Failed to stop");
        }
    };

    return (
        <div className="space-y-6">
            <RecipientInput
                onBatchStart={handleBatchStart}
                loading={loading}
            />

            {batchQueue.length > 0 && (
                <div className="animate-slide-up">
                    <EmailQueue
                        queue={batchQueue}
                        currentIndex={batchCurrentIdx}
                        stats={batchStats}
                        batchMode={batchMode}
                        autoRunning={autoRunning}
                        onSelect={(idx) => setBatchCurrentIdx(idx)}
                        onApprove={handleBatchApprove}
                        onSkip={handleBatchSkip}
                        onAutoRun={handleAutoRun}
                        onStopAuto={handleStopAuto}
                    />
                </div>
            )}
        </div>
    );
}