"use client";
import { useState, useRef, useCallback } from "react";
import type { MailMessage } from "@/app/dashboard/mail/page";
import { formatBytes } from "@/lib/format";

interface AttachmentFile {
  file: File;
  name: string;
  size: number;
}

export default function ComposeModal({ replyTo, onClose, onSent }: {
  replyTo: MailMessage | null;
  onClose: () => void;
  onSent: () => void;
}) {
  const [to, setTo] = useState(replyTo ? replyTo.from[0]?.address ?? "" : "");
  const [cc, setCc] = useState("");
  const [subject, setSubject] = useState(replyTo ? `Re: ${replyTo.subject.replace(/^Re:\s*/i, "")}` : "");
  const [body, setBody] = useState(replyTo ? `\n\n---\n${replyTo.text?.slice(0, 500) ?? ""}` : "");
  const [attachments, setAttachments] = useState<AttachmentFile[]>([]);
  const [sending, setSending] = useState(false);
  const [error, setError] = useState("");
  const [dragOver, setDragOver] = useState(false);
  const fileInputRef = useRef<HTMLInputElement>(null);

  const addFiles = useCallback((files: FileList | null) => {
    if (!files) return;
    const newFiles = Array.from(files).map((f) => ({ file: f, name: f.name, size: f.size }));
    setAttachments((prev) => [...prev, ...newFiles]);
  }, []);

  const removeAttachment = (index: number) => {
    setAttachments((prev) => prev.filter((_, i) => i !== index));
  };

  const handleDrop = useCallback((e: React.DragEvent) => {
    e.preventDefault();
    setDragOver(false);
    addFiles(e.dataTransfer.files);
  }, [addFiles]);

  const handleSend = async (e: React.FormEvent) => {
    e.preventDefault();
    setSending(true);
    setError("");

    try {
      if (attachments.length > 0) {
        // Use FormData for attachments
        const formData = new FormData();
        formData.append("to", to);
        if (cc) formData.append("cc", cc);
        formData.append("subject", subject);
        formData.append("text", body);
        formData.append("html", `<pre style="font-family:inherit;white-space:pre-wrap">${body.replace(/</g, "&lt;")}</pre>`);
        attachments.forEach((att) => {
          formData.append("attachments", att.file, att.name);
        });

        const res = await fetch("/api/mail/send", { method: "POST", body: formData });
        const data = await res.json();
        if (!res.ok) throw new Error(data.error || "Gönderilemedi");
      } else {
        // JSON for simple messages
        const res = await fetch("/api/mail/send", {
          method: "POST",
          headers: { "Content-Type": "application/json" },
          body: JSON.stringify({
            to, cc: cc || undefined, subject, text: body,
            html: `<pre style="font-family:inherit;white-space:pre-wrap">${body.replace(/</g, "&lt;")}</pre>`,
          }),
        });
        const data = await res.json();
        if (!res.ok) throw new Error(data.error || "Gönderilemedi");
      }
      onSent();
    } catch (err: any) {
      setError(err.message);
    }
    setSending(false);
  };

  const totalSize = attachments.reduce((sum, a) => sum + a.size, 0);

  return (
    <div className="modal-overlay" onClick={(e) => e.target === e.currentTarget && onClose()}>
      <div className="modal" style={{ maxWidth: 620 }}>
        <div className="modal-header">
          <h2 className="modal-title">{replyTo ? "Yanıtla" : "Yeni Mail"}</h2>
          <button className="modal-close" onClick={onClose}>✕</button>
        </div>
        <form onSubmit={handleSend}>
          <div className="modal-body form-group">
            {error && <div className="error-msg">{error}</div>}
            <div>
              <label className="label">Alıcı</label>
              <input type="email" className="input" placeholder="alici@domain.com" value={to}
                onChange={(e) => setTo(e.target.value)} required autoFocus />
            </div>
            <div>
              <label className="label">CC (isteğe bağlı)</label>
              <input type="text" className="input" placeholder="cc@domain.com" value={cc}
                onChange={(e) => setCc(e.target.value)} />
            </div>
            <div>
              <label className="label">Konu</label>
              <input type="text" className="input" value={subject}
                onChange={(e) => setSubject(e.target.value)} required />
            </div>
            <div>
              <label className="label">Mesaj</label>
              <textarea className="input" rows={8} value={body}
                onChange={(e) => setBody(e.target.value)}
                style={{ resize: "vertical", fontFamily: "inherit" }} />
            </div>

            {/* Attachment zone */}
            <div
              className={`compose-dropzone ${dragOver ? "active" : ""}`}
              onDragOver={(e) => { e.preventDefault(); setDragOver(true); }}
              onDragLeave={() => setDragOver(false)}
              onDrop={handleDrop}
              onClick={() => fileInputRef.current?.click()}
            >
              <input
                ref={fileInputRef}
                type="file"
                multiple
                style={{ display: "none" }}
                onChange={(e) => { addFiles(e.target.files); e.target.value = ""; }}
              />
              <span style={{ fontSize: 20 }}>📎</span>
              <span>Dosya sürükleyin veya tıklayın</span>
            </div>

            {/* Attachment list */}
            {attachments.length > 0 && (
              <div className="compose-attachments">
                {attachments.map((att, i) => (
                  <div key={i} className="compose-att-item">
                    <span>📎 {att.name}</span>
                    <span style={{ color: "var(--text-muted)", fontSize: 11 }}>{formatBytes(att.size)}</span>
                    <button type="button" className="att-remove" onClick={() => removeAttachment(i)}>✕</button>
                  </div>
                ))}
                <div style={{ fontSize: 11, color: "var(--text-muted)", marginTop: 4 }}>
                  Toplam: {formatBytes(totalSize)} — {attachments.length} dosya
                </div>
              </div>
            )}
          </div>
          <div className="modal-footer">
            <button type="button" className="btn btn-ghost" onClick={onClose}>İptal</button>
            <button type="submit" className="btn btn-primary" disabled={sending}>
              {sending ? <span className="spinner" /> : <SendIcon />} Gönder
            </button>
          </div>
        </form>
      </div>
    </div>
  );
}

function SendIcon() { return <svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><line x1="22" x2="11" y1="2" y2="13"/><polygon points="22 2 15 22 11 13 2 9 22 2"/></svg>; }