import { format } from "date-fns";
import { Calendar } from "lucide-react";
import { useEffect, useRef, useState } from "react";
import { createPortal } from "react-dom";

export const DEFAULT_PHASE_COLOR = "#14b8a6";

const PHASE_COLOR_OPTIONS = [
  "#14b8a6",
  "#0ea5e9",
  "#6366f1",
  "#a855f7",
  "#ec4899",
  "#f59e0b",
  "#22c55e",
  "#64748b",
];

export interface PhaseCreateInput {
  name: string;
  start_date: string;
  end_date: string;
  color: string;
}

interface PhaseCreatePopoverProps {
  anchor: { top: number; left: number };
  startDate: string;
  endDate: string;
  onCancel: () => void;
  onSave: (input: PhaseCreateInput) => void;
  isSaving?: boolean;
}

export function PhaseCreatePopover({
  anchor,
  startDate,
  endDate,
  onCancel,
  onSave,
  isSaving = false,
}: PhaseCreatePopoverProps) {
  const popoverRef = useRef<HTMLDivElement>(null);
  const [name, setName] = useState("Phase");
  const [color, setColor] = useState(DEFAULT_PHASE_COLOR);
  const [showColors, setShowColors] = useState(false);

  useEffect(() => {
    setName("Phase");
    setColor(DEFAULT_PHASE_COLOR);
    setShowColors(false);
  }, [startDate, endDate]);

  useEffect(() => {
    const onKey = (event: KeyboardEvent) => {
      if (event.key === "Escape") onCancel();
    };
    const onDown = (event: MouseEvent) => {
      if (popoverRef.current?.contains(event.target as Node)) return;
      onCancel();
    };
    window.addEventListener("keydown", onKey);
    document.addEventListener("mousedown", onDown);
    return () => {
      window.removeEventListener("keydown", onKey);
      document.removeEventListener("mousedown", onDown);
    };
  }, [onCancel]);

  const rangeLabel =
    startDate === endDate
      ? format(new Date(startDate), "d MMM yyyy")
      : `${format(new Date(startDate), "d MMM")} – ${format(new Date(endDate), "d MMM yyyy")}`;

  const style = {
    top: Math.min(anchor.top, window.innerHeight - 200),
    left: Math.min(Math.max(8, anchor.left), window.innerWidth - 320),
  };

  return createPortal(
    <div className="phase-create-popover" ref={popoverRef} style={style}>
      <input
        aria-label="Phase name"
        autoFocus
        className="phase-create-popover-input"
        onChange={(event) => setName(event.target.value)}
        onKeyDown={(event) => {
          if (event.key === "Enter" && name.trim()) {
            onSave({ name: name.trim(), start_date: startDate, end_date: endDate, color });
          }
        }}
        placeholder="Phase"
        type="text"
        value={name}
      />
      <div className="phase-create-popover-footer">
        <button className="link-button" onClick={onCancel} type="button">
          Cancel
        </button>
        <div className="phase-create-popover-tools">
          <div className="phase-color-picker">
            <button
              aria-label="Phase color"
              className="phase-color-trigger"
              onClick={() => setShowColors((open) => !open)}
              style={{ background: color }}
              type="button"
            />
            {showColors ? (
              <div className="phase-color-menu">
                {PHASE_COLOR_OPTIONS.map((option) => (
                  <button
                    aria-label={`Color ${option}`}
                    className={option === color ? "is-selected" : undefined}
                    key={option}
                    onClick={() => {
                      setColor(option);
                      setShowColors(false);
                    }}
                    style={{ background: option }}
                    type="button"
                  />
                ))}
              </div>
            ) : null}
          </div>
          <span className="phase-date-hint" title={rangeLabel}>
            <Calendar aria-hidden size={16} />
          </span>
          <button
            className="primary-button"
            disabled={isSaving || !name.trim()}
            onClick={() =>
              onSave({ name: name.trim(), start_date: startDate, end_date: endDate, color })
            }
            type="button"
          >
            Save
          </button>
        </div>
      </div>
    </div>,
    document.body,
  );
}

export function phasePopoverAnchorFromTrack(
  trackRect: DOMRect,
  startIndex: number,
  endIndex: number,
  totalDays: number,
): { top: number; left: number } {
  const start = Math.min(startIndex, endIndex);
  const end = Math.max(startIndex, endIndex);
  const span = end - start + 1;
  const leftPct = start / totalDays;
  const widthPct = span / totalDays;
  const centerX = trackRect.left + trackRect.width * (leftPct + widthPct / 2);
  return { top: trackRect.top - 12, left: centerX - 150 };
}