import { useState, useEffect, useRef } from "react";
import { AnimatePresence, motion, useReducedMotion } from "framer-motion";
import { OverlayScrollbarsComponent } from "overlayscrollbars-react";
import { X } from "lucide-react";
import { useBoardStore } from "@/stores/board-store";
import { MarkdownEditor } from "@/components/card-detail/MarkdownEditor";
import { ChecklistSection } from "@/components/card-detail/ChecklistSection";
import { LabelPicker } from "@/components/card-detail/LabelPicker";
import { DueDatePicker } from "@/components/card-detail/DueDatePicker";
import { AttachmentSection } from "@/components/card-detail/AttachmentSection";
import { PriorityPicker } from "@/components/card-detail/PriorityPicker";
import { CommentsSection } from "@/components/card-detail/CommentsSection";
import { springs, staggerContainer, fadeSlideUp } from "@/lib/motion";

interface CardDetailModalProps {
  cardId: string | null;
  onClose: () => void;
}

export function CardDetailModal({ cardId, onClose }: CardDetailModalProps) {
  const card = useBoardStore((s) =>
    cardId ? s.board?.cards[cardId] ?? null : null
  );
  const boardLabels = useBoardStore((s) => s.board?.labels ?? []);
  const updateCard = useBoardStore((s) => s.updateCard);

  const open = cardId != null && card != null;
  const prefersReducedMotion = useReducedMotion();
  const instant = { duration: 0 };

  return (
    <AnimatePresence>
      {open && card && cardId && (
        <>
          {/* Backdrop */}
          <motion.div
            className="fixed inset-0 z-50 bg-black/40 backdrop-blur-sm"
            initial={{ opacity: 0 }}
            animate={{ opacity: 1 }}
            exit={{ opacity: 0 }}
            transition={prefersReducedMotion ? instant : { duration: 0.2 }}
            onClick={onClose}
          />

          {/* Modal */}
          <div
            className="fixed inset-0 z-50 flex items-center justify-center p-4"
            onClick={onClose}
          >
            <motion.div
              layoutId={prefersReducedMotion ? undefined : `card-${cardId}`}
              className="relative w-full max-w-4xl overflow-hidden rounded-xl bg-pylon-surface shadow-2xl"
              initial={prefersReducedMotion ? { opacity: 0 } : undefined}
              animate={prefersReducedMotion ? { opacity: 1 } : undefined}
              exit={prefersReducedMotion ? { opacity: 0 } : undefined}
              transition={prefersReducedMotion ? instant : springs.gentle}
              onClick={(e) => e.stopPropagation()}
            >
              <EscapeHandler onClose={onClose} />
              <span className="sr-only">Card detail editor</span>

              {/* Header: cover color background + title + close */}
              <div
                className="relative flex items-center gap-3 px-6 py-4"
                style={{
                  backgroundColor: card.coverColor
                    ? `oklch(55% 0.12 ${card.coverColor})`
                    : undefined,
                }}
              >
                <InlineTitle
                  cardId={cardId}
                  title={card.title}
                  updateCard={updateCard}
                  hasColor={card.coverColor != null}
                />
                <button
                  onClick={onClose}
                  className={`absolute right-4 top-1/2 -translate-y-1/2 rounded-md p-1 transition-colors ${
                    card.coverColor
                      ? "text-white/70 hover:bg-white/20 hover:text-white"
                      : "text-pylon-text-secondary hover:bg-pylon-column hover:text-pylon-text"
                  }`}
                  aria-label="Close"
                >
                  <X className="size-5" />
                </button>
              </div>

              {/* Dashboard grid body */}
              <OverlayScrollbarsComponent
                className="max-h-[calc(85vh-4rem)]"
                options={{ scrollbars: { theme: "os-theme-pylon", autoHide: "scroll", autoHideDelay: 600, clickScroll: true }, overflow: { x: "hidden" } }}
                defer
              >
              <motion.div
                className="grid grid-cols-2 gap-4 p-5"
                variants={staggerContainer(0.05)}
                initial="hidden"
                animate="visible"
              >
                {/* Row 1: Labels + Due Date */}
                <motion.div
                  className="rounded-lg bg-pylon-column/50 p-4"
                  variants={fadeSlideUp}
                  transition={springs.bouncy}
                >
                  <LabelPicker
                    cardId={cardId}
                    cardLabelIds={card.labels}
                    boardLabels={boardLabels}
                  />
                </motion.div>

                <motion.div
                  className="rounded-lg bg-pylon-column/50 p-4"
                  variants={fadeSlideUp}
                  transition={springs.bouncy}
                >
                  <DueDatePicker cardId={cardId} dueDate={card.dueDate} />
                </motion.div>

                {/* Row 2: Checklist + Description */}
                <motion.div
                  className="rounded-lg bg-pylon-column/50 p-4"
                  variants={fadeSlideUp}
                  transition={springs.bouncy}
                >
                  <ChecklistSection
                    cardId={cardId}
                    checklist={card.checklist}
                  />
                </motion.div>

                <motion.div
                  className="rounded-lg bg-pylon-column/50 p-4"
                  variants={fadeSlideUp}
                  transition={springs.bouncy}
                >
                  <MarkdownEditor cardId={cardId} value={card.description} />
                </motion.div>

                {/* Row 3: Priority + Cover */}
                <motion.div
                  className="rounded-lg bg-pylon-column/50 p-4"
                  variants={fadeSlideUp}
                  transition={springs.bouncy}
                >
                  <PriorityPicker cardId={cardId} priority={card.priority} />
                </motion.div>

                <motion.div
                  className="rounded-lg bg-pylon-column/50 p-4"
                  variants={fadeSlideUp}
                  transition={springs.bouncy}
                >
                  <CoverColorPicker
                    cardId={cardId}
                    coverColor={card.coverColor}
                  />
                </motion.div>

                {/* Row 4: Attachments (full width) */}
                <motion.div
                  className="col-span-2 rounded-lg bg-pylon-column/50 p-4"
                  variants={fadeSlideUp}
                  transition={springs.bouncy}
                >
                  <AttachmentSection
                    cardId={cardId}
                    attachments={card.attachments}
                  />
                </motion.div>

                {/* Row 5: Comments (full width) */}
                <motion.div
                  className="col-span-2 rounded-lg bg-pylon-column/50 p-4"
                  variants={fadeSlideUp}
                  transition={springs.bouncy}
                >
                  <CommentsSection cardId={cardId} comments={card.comments} />
                </motion.div>
              </motion.div>
              </OverlayScrollbarsComponent>
            </motion.div>
          </div>
        </>
      )}
    </AnimatePresence>
  );
}

/* ---------- Escape key handler ---------- */

function EscapeHandler({ onClose }: { onClose: () => void }) {
  useEffect(() => {
    function handleKeyDown(e: KeyboardEvent) {
      if (e.key === "Escape") onClose();
    }
    document.addEventListener("keydown", handleKeyDown);
    return () => document.removeEventListener("keydown", handleKeyDown);
  }, [onClose]);
  return null;
}

/* ---------- Inline editable title ---------- */

interface InlineTitleProps {
  cardId: string;
  title: string;
  updateCard: (cardId: string, updates: { title: string }) => void;
  hasColor: boolean;
}

function InlineTitle({ cardId, title, updateCard, hasColor }: InlineTitleProps) {
  const [editing, setEditing] = useState(false);
  const [draft, setDraft] = useState(title);
  const inputRef = useRef<HTMLInputElement>(null);

  useEffect(() => {
    setDraft(title);
  }, [title]);

  useEffect(() => {
    if (editing && inputRef.current) {
      inputRef.current.focus();
      inputRef.current.select();
    }
  }, [editing]);

  function handleSave() {
    const trimmed = draft.trim();
    if (trimmed && trimmed !== title) {
      updateCard(cardId, { title: trimmed });
    } else {
      setDraft(title);
    }
    setEditing(false);
  }

  function handleKeyDown(e: React.KeyboardEvent) {
    if (e.key === "Enter") {
      e.preventDefault();
      handleSave();
    } else if (e.key === "Escape") {
      setDraft(title);
      setEditing(false);
    }
  }

  const textColor = hasColor ? "text-white" : "text-pylon-text";
  const hoverColor = hasColor ? "hover:text-white/80" : "hover:text-pylon-accent";

  if (editing) {
    return (
      <input
        ref={inputRef}
        value={draft}
        onChange={(e) => setDraft(e.target.value)}
        onBlur={handleSave}
        onKeyDown={handleKeyDown}
        className={`flex-1 font-heading text-xl bg-transparent outline-none border-b pb-0.5 ${
          hasColor ? "text-white border-white/50" : "text-pylon-text border-pylon-accent"
        }`}
      />
    );
  }

  return (
    <h2
      onClick={() => setEditing(true)}
      className={`flex-1 cursor-pointer font-heading text-xl transition-colors ${textColor} ${hoverColor}`}
    >
      {title}
    </h2>
  );
}

/* ---------- Cover color picker ---------- */

function CoverColorPicker({
  cardId,
  coverColor,
}: {
  cardId: string;
  coverColor: string | null;
}) {
  const updateCard = useBoardStore((s) => s.updateCard);
  const presets = [
    { hue: "160", label: "Teal" },
    { hue: "240", label: "Blue" },
    { hue: "300", label: "Purple" },
    { hue: "350", label: "Pink" },
    { hue: "25", label: "Red" },
    { hue: "55", label: "Orange" },
    { hue: "85", label: "Yellow" },
    { hue: "130", label: "Lime" },
    { hue: "200", label: "Cyan" },
    { hue: "0", label: "Slate" },
  ];

  return (
    <div className="flex flex-col gap-2">
      <h4 className="font-mono text-xs uppercase tracking-widest text-pylon-text-secondary">
        Cover
      </h4>
      <div className="flex flex-wrap gap-1.5">
        <button
          onClick={() => updateCard(cardId, { coverColor: null })}
          className="flex size-6 items-center justify-center rounded-full border border-border text-xs text-pylon-text-secondary hover:bg-pylon-column"
          title="None"
        >
          &times;
        </button>
        {presets.map(({ hue, label }) => (
          <button
            key={hue}
            onClick={() => updateCard(cardId, { coverColor: hue })}
            className="size-6 rounded-full transition-transform hover:scale-110"
            style={{
              backgroundColor: `oklch(55% 0.12 ${hue})`,
              outline:
                coverColor === hue ? "2px solid currentColor" : "none",
              outlineOffset: "1px",
            }}
            title={label}
          />
        ))}
      </div>
    </div>
  );
}