import React, { useState, useRef, useEffect } from "react";
import ReactDOM from "react-dom";

export default function SignatureCapture({ onSave, onClose, title }) {
  const [mode, setMode] = useState("draw");
  const [typedName, setTypedName] = useState("");
  const [signerName, setSignerName] = useState("");
  const canvasRef = useRef(null);
  const isDrawing = useRef(false);

  useEffect(() => {
    if (mode === "draw" && canvasRef.current) {
      const canvas = canvasRef.current;
      const ctx = canvas.getContext("2d");
      ctx.fillStyle = "#fff";
      ctx.fillRect(0, 0, canvas.width, canvas.height);
      ctx.strokeStyle = "#333";
      ctx.lineWidth = 2;
      ctx.lineCap = "round";
    }
  }, [mode]);

  const getPos = (e) => {
    const rect = canvasRef.current.getBoundingClientRect();
    const touch = e.touches ? e.touches[0] : e;
    return { x: touch.clientX - rect.left, y: touch.clientY - rect.top };
  };

  const startDraw = (e) => {
    e.preventDefault();
    isDrawing.current = true;
    const ctx = canvasRef.current.getContext("2d");
    const pos = getPos(e);
    ctx.beginPath();
    ctx.moveTo(pos.x, pos.y);
  };

  const draw = (e) => {
    e.preventDefault();
    if (!isDrawing.current) return;
    const ctx = canvasRef.current.getContext("2d");
    const pos = getPos(e);
    ctx.lineTo(pos.x, pos.y);
    ctx.stroke();
  };

  const stopDraw = () => { isDrawing.current = false; };

  const clearCanvas = () => {
    const ctx = canvasRef.current.getContext("2d");
    ctx.fillStyle = "#fff";
    ctx.fillRect(0, 0, canvasRef.current.width, canvasRef.current.height);
  };

  const handleSave = () => {
    if (!signerName.trim()) return;
    if (mode === "draw") {
      const dataUrl = canvasRef.current.toDataURL("image/png");
      onSave(dataUrl, "drawn", signerName.trim());
    } else {
      onSave(typedName, "typed", signerName.trim());
    }
  };

  return ReactDOM.createPortal(
    <div className="sigOverlay" onClick={onClose}>
      <div className="sigModal" onClick={(e) => e.stopPropagation()}>
        <div className="sigHeader">
          <h3>{title || "Capture Signature"}</h3>
          <button className="woDispatchClose" onClick={onClose}>&times;</button>
        </div>
        <div className="sigBody">
          <div className="sigNameField">
            <label>Full Name</label>
            <input
              className="form-control"
              value={signerName}
              onChange={(e) => setSignerName(e.target.value)}
              placeholder="Enter signer's full name"
            />
          </div>
          <div className="sigModeTabs">
            <button className={`sigModeTab ${mode === "draw" ? "active" : ""}`} onClick={() => setMode("draw")}>Draw</button>
            <button className={`sigModeTab ${mode === "type" ? "active" : ""}`} onClick={() => setMode("type")}>Type</button>
          </div>
          {mode === "draw" ? (
            <div className="sigCanvasWrap">
              <canvas
                ref={canvasRef}
                width={460}
                height={180}
                className="sigCanvas"
                onMouseDown={startDraw}
                onMouseMove={draw}
                onMouseUp={stopDraw}
                onMouseLeave={stopDraw}
                onTouchStart={startDraw}
                onTouchMove={draw}
                onTouchEnd={stopDraw}
              />
              <button className="sigClearBtn" onClick={clearCanvas}>Clear</button>
            </div>
          ) : (
            <div className="sigTypeWrap">
              <input
                className="form-control sigTypeInput"
                value={typedName}
                onChange={(e) => setTypedName(e.target.value)}
                placeholder="Type your name"
              />
              {typedName && <div className="sigTypePreview">{typedName}</div>}
            </div>
          )}
        </div>
        <div className="sigFooter">
          <button className="btn btn-default" onClick={onClose}>Cancel</button>
          <button className="btn btn-primary" onClick={handleSave} disabled={!signerName.trim() || (mode === "type" && !typedName.trim())}>Save Signature</button>
        </div>
      </div>
    </div>,
    document.body
  );
}