// frontend/components/tasks/KanbanView.tsx
"use client";
import { useState } from "react";
import { Icon } from "@/components/Icon";
import { cx } from "@/lib/cx";
import { COLUMNS } from "@/lib/tasks/tree";
import type { Person, Project, Status, Task } from "@/lib/types";
import { KanbanCard } from "./KanbanCard";

export function KanbanView({
  tasks,
  people,
  projects,
  onOpen,
  onMove,
  onAdd,
  onReorder,
}: {
  tasks: Task[];
  people: Record<string, Person>;
  projects: Record<string, Project>;
  onOpen: (id: string) => void;
  onMove: (id: string, status: Status) => void;
  onAdd: (status: Status, title: string) => void;
  onReorder?: (ids: string[]) => void;
}) {
  const [dragId, setDragId] = useState<string | null>(null);
  const [overCol, setOverCol] = useState<string | null>(null);
  const [overId, setOverId] = useState<string | null>(null);
  const [overAfter, setOverAfter] = useState(false);
  const [addCol, setAddCol] = useState<string | null>(null);
  const [text, setText] = useState("");
  const submit = (status: Status) => {
    if (text.trim()) onAdd(status, text.trim());
    setText("");
    setAddCol(null);
  };
  const clearDrag = () => {
    setDragId(null);
    setOverCol(null);
    setOverId(null);
  };
  const handleDrop = async (colId: string) => {
    const id = dragId;
    const oid = overId;
    const oaft = overAfter;
    clearDrag();
    if (!id) return;
    const dragged = tasks.find((t) => t.id === id);
    const sameCol = dragged?.status === colId;
    const colIds = tasks.filter((t) => t.status === colId && t.id !== id).map((t) => t.id);
    let idx = colIds.length;
    if (oid && oid !== id) {
      const at = colIds.indexOf(oid);
      if (at >= 0) idx = at + (oaft ? 1 : 0);
    }
    const newIds = [...colIds.slice(0, idx), id, ...colIds.slice(idx)];
    if (!sameCol) await onMove(id, colId as Status);
    if (onReorder) await onReorder(newIds);
  };
  return (
    <div className="kboard">
      {COLUMNS.map((col) => {
        const items = tasks.filter((t) => t.status === col.id);
        return (
          <div
            key={col.id}
            className={cx("kcol", overCol === col.id && "over")}
            onDragOver={(e) => {
              e.preventDefault();
              if (overCol !== col.id) setOverCol(col.id);
            }}
            onDragLeave={(e) => {
              if (e.currentTarget === e.target) setOverCol(null);
            }}
            onDrop={(e) => {
              e.preventDefault();
              void handleDrop(col.id);
            }}
          >
            <div className="kcol-head">
              <span className="kcol-dot" style={{ background: col.accent }} />
              <span className="kcol-label">{col.label}</span>
              <span className="kcol-count">{items.length}</span>
              <button
                className="kcol-add"
                onClick={() => {
                  setAddCol(col.id);
                  setText("");
                }}
                aria-label="작업 추가"
              >
                <Icon name="plus" />
              </button>
            </div>
            <div className="kcol-body">
              {addCol === col.id && (
                <div className="quickadd">
                  <input
                    autoFocus
                    value={text}
                    placeholder="작업 입력 후 Enter…"
                    onChange={(e) => setText(e.target.value)}
                    onKeyDown={(e) => {
                      if (e.key === "Enter") submit(col.id as Status);
                      if (e.key === "Escape") setAddCol(null);
                    }}
                    onBlur={() => submit(col.id as Status)}
                  />
                </div>
              )}
              {items.map((t) => (
                <KanbanCard
                  key={t.id}
                  task={t}
                  people={people}
                  projects={projects}
                  onOpen={onOpen}
                  dragging={dragId === t.id}
                  dropPos={dragId && dragId !== t.id && overId === t.id ? (overAfter ? "after" : "before") : null}
                  onDragStart={(e) => {
                    setDragId(t.id);
                    e.dataTransfer.effectAllowed = "move";
                  }}
                  onDragEnd={clearDrag}
                  onDragOver={(e) => {
                    if (!dragId || dragId === t.id) return;
                    const r = e.currentTarget.getBoundingClientRect();
                    setOverId(t.id);
                    setOverAfter(e.clientY > r.top + r.height / 2);
                  }}
                />
              ))}
              {items.length === 0 && addCol !== col.id && (
                <div className="kcol-empty">여기로 작업을 옮겨보세요</div>
              )}
            </div>
          </div>
        );
      })}
    </div>
  );
}