import React, { useEffect, useLayoutEffect, useMemo, useRef, useState } from 'react';
import { createPortal } from 'react-dom';

import { ipcChannels } from '../../shared/ipc/contracts';
import {
  INITIATIVE_CONDITION_IDS,
  type InitiativeConditionId,
  type InitiativeEntry,
} from '../../shared/types/initiative';
import { useEditorI18n } from '../editor/i18n/EditorI18nContext';
import { getDndApi } from '../shared/dndApi';
import { InitiativeConditionChips } from '../shared/initiative/InitiativeConditionChips';
import { useInitiativeState } from '../shared/initiative/useInitiativeState';
import { usePlayerImageUrl } from '../shared/playerToken/usePlayerImageUrl';
import { useAssetUrl } from '../shared/useAssetImageUrl';
import { Button, Input } from '../shared/ui/controls';

import styles from './InitiativeApp.module.css';

const DND_MIME = 'application/x-dnd-initiative-entry-id';
const CONDITION_MENU_WIDTH = 200;
/** Компактная высота меню; фактическая не больше доступного места на экране. */
const CONDITION_MENU_MAX_H = 220;
const CONDITION_MENU_GAP = 6;
const CONDITION_MENU_EDGE = 8;

function EntryAvatar({ entry }: { entry: InitiativeEntry }) {
  if (entry.kind === 'manual') {
    return (
      <div className={styles.avatar} style={{ background: entry.gradient }} aria-hidden>
        <span className={styles.letter}>{entry.letter}</span>
      </div>
    );
  }
  if (entry.kind === 'npc') {
    return <NpcAvatar assetId={entry.avatarAssetId} name={entry.name} />;
  }
  return <PlayerAvatar playerId={entry.playerId} name={entry.name} />;
}

function NpcAvatar({ assetId, name }: { assetId: string | null; name: string }) {
  const url = useAssetUrl(assetId as import('../../shared/types').AssetId | null);
  if (url) {
    return (
      <div className={styles.avatar}>
        <img src={url} alt="" className={styles.avatarImg} />
      </div>
    );
  }
  const letter = (name.trim()[0] ?? '?').toUpperCase();
  return (
    <div className={styles.avatar} style={{ background: 'linear-gradient(135deg,#334155,#0f172a)' }}>
      <span className={styles.letter}>{letter}</span>
    </div>
  );
}

function PlayerAvatar({ playerId, name }: { playerId: string; name: string }) {
  const url = usePlayerImageUrl(playerId as import('../../shared/types').PlayerId);
  if (url) {
    return (
      <div className={styles.avatar}>
        <img src={url} alt="" className={styles.avatarImg} />
      </div>
    );
  }
  const letter = (name.trim()[0] ?? '?').toUpperCase();
  return (
    <div className={styles.avatar} style={{ background: 'linear-gradient(135deg,#1d4ed8,#0f172a)' }}>
      <span className={styles.letter}>{letter}</span>
    </div>
  );
}

function QueueSlot({
  entry,
  active,
  conditions,
  onSelect,
  onRemove,
  onDragStart,
  onDragOver,
  onDrop,
  conditionsOpen,
  onToggleConditions,
  onAddCondition,
  onRemoveCondition,
}: {
  entry: InitiativeEntry;
  active: boolean;
  conditions: readonly InitiativeConditionId[];
  onSelect: () => void;
  onRemove: () => void;
  onDragStart: (e: React.DragEvent) => void;
  onDragOver: (e: React.DragEvent) => void;
  onDrop: (e: React.DragEvent) => void;
  conditionsOpen: boolean;
  onToggleConditions: () => void;
  onAddCondition: (id: InitiativeConditionId) => void;
  onRemoveCondition: (id: InitiativeConditionId) => void;
}) {
  const { t } = useEditorI18n();
  const available = INITIATIVE_CONDITION_IDS.filter((id) => !conditions.includes(id));
  const addBtnRef = useRef<HTMLButtonElement | null>(null);
  const [menuPos, setMenuPos] = useState<{ top: number; left: number; maxHeight: number } | null>(
    null,
  );

  useLayoutEffect(() => {
    if (!conditionsOpen) {
      setMenuPos(null);
      return;
    }
    const btn = addBtnRef.current;
    if (!btn) return;
    const place = () => {
      const r = btn.getBoundingClientRect();
      const left = Math.max(
        CONDITION_MENU_EDGE,
        Math.min(
          window.innerWidth - CONDITION_MENU_WIDTH - CONDITION_MENU_EDGE,
          r.left,
        ),
      );
      const spaceBelow = window.innerHeight - r.bottom - CONDITION_MENU_GAP - CONDITION_MENU_EDGE;
      const spaceAbove = r.top - CONDITION_MENU_GAP - CONDITION_MENU_EDGE;
      // Предпочитаем под кнопкой; если снизу мало места — над ней.
      const openBelow = spaceBelow >= 120 || spaceBelow >= spaceAbove;
      const available = Math.max(80, openBelow ? spaceBelow : spaceAbove);
      const maxHeight = Math.min(CONDITION_MENU_MAX_H, available);
      const top = openBelow
        ? r.bottom + CONDITION_MENU_GAP
        : Math.max(CONDITION_MENU_EDGE, r.top - CONDITION_MENU_GAP - maxHeight);
      setMenuPos({ top, left, maxHeight });
    };
    place();
    window.addEventListener('resize', place);
    window.addEventListener('scroll', place, true);
    return () => {
      window.removeEventListener('resize', place);
      window.removeEventListener('scroll', place, true);
    };
  }, [conditionsOpen]);

  useEffect(() => {
    if (!conditionsOpen) return;
    const onDown = (e: MouseEvent) => {
      const target = e.target as Node | null;
      if (addBtnRef.current?.contains(target)) return;
      const menu = document.getElementById(`initiative-condition-menu-${entry.id}`);
      if (menu?.contains(target)) return;
      onToggleConditions();
    };
    document.addEventListener('mousedown', onDown);
    return () => document.removeEventListener('mousedown', onDown);
  }, [conditionsOpen, entry.id, onToggleConditions]);

  return (
    <div
      className={[styles.slot, active ? styles.slotActive : ''].filter(Boolean).join(' ')}
      data-testid={`initiative-slot-${entry.id}`}
      data-active={active ? '1' : '0'}
      draggable
      onDragStart={onDragStart}
      onDragOver={onDragOver}
      onDrop={onDrop}
      onClick={onSelect}
    >
      <EntryAvatar entry={entry} />
      <div className={styles.slotName} title={entry.name}>
        {entry.name}
      </div>
      <InitiativeConditionChips
        conditions={conditions}
        removable
        onRemove={onRemoveCondition}
      />
      <div className={styles.slotActions}>
        <button
          ref={addBtnRef}
          type="button"
          className={styles.miniBtn}
          title={t('initiative.conditions')}
          onClick={(e) => {
            e.stopPropagation();
            onToggleConditions();
          }}
        >
          +
        </button>
        <button
          type="button"
          className={styles.miniBtn}
          title={t('initiative.toReserve')}
          onClick={(e) => {
            e.stopPropagation();
            onRemove();
          }}
        >
          ×
        </button>
      </div>
      {conditionsOpen && menuPos
        ? createPortal(
            <div
              id={`initiative-condition-menu-${entry.id}`}
              className={styles.conditionMenu}
              style={{
                top: menuPos.top,
                left: menuPos.left,
                width: CONDITION_MENU_WIDTH,
                maxHeight: menuPos.maxHeight,
              }}
              onClick={(e) => e.stopPropagation()}
              onMouseDown={(e) => e.stopPropagation()}
            >
              {available.length === 0 ? (
                <div className={styles.conditionEmpty}>{t('initiative.conditionsEmpty')}</div>
              ) : (
                available.map((id) => (
                  <button
                    key={id}
                    type="button"
                    className={styles.conditionItem}
                    onClick={() => onAddCondition(id)}
                  >
                    {t(`initiative.condition.${id}`)}
                  </button>
                ))
              )}
            </div>,
            document.body,
          )
        : null}
    </div>
  );
}

export function InitiativeApp() {
  const { t } = useEditorI18n();
  const api = getDndApi();
  const [state, initiativeApi] = useInitiativeState();
  const [manualName, setManualName] = useState('');
  const [conditionsFor, setConditionsFor] = useState<string | null>(null);

  useEffect(() => {
    const onKey = (e: KeyboardEvent) => {
      if (e.key === 'Escape') {
        void api.invoke(ipcChannels.windows.closeInitiative, {});
      }
    };
    window.addEventListener('keydown', onKey);
    return () => window.removeEventListener('keydown', onKey);
  }, [api]);

  const orderEntries = useMemo(() => {
    if (!state) return [];
    return state.order.map((id) => state.entries[id]).filter(Boolean) as InitiativeEntry[];
  }, [state]);

  const reserveEntries = useMemo(() => {
    if (!state) return [];
    return state.reserve.map((id) => state.entries[id]).filter(Boolean) as InitiativeEntry[];
  }, [state]);

  if (!state) {
    return <div className={styles.page} data-testid="initiative-app" />;
  }

  const reorderDrop = (targetId: string, e: React.DragEvent) => {
    e.preventDefault();
    const fromId = e.dataTransfer.getData(DND_MIME);
    if (!fromId || fromId === targetId) return;
    const next = [...state.order];
    const fromIdx = next.indexOf(fromId);
    const toIdx = next.indexOf(targetId);
    if (fromIdx < 0 || toIdx < 0) return;
    next.splice(fromIdx, 1);
    next.splice(toIdx, 0, fromId);
    void initiativeApi.dispatch({ kind: 'reorder', order: next });
  };

  const addManual = () => {
    const name = manualName.trim();
    if (!name) return;
    void initiativeApi.dispatch({ kind: 'addManual', name });
    setManualName('');
  };

  return (
    <div className={styles.page} data-testid="initiative-app">
      <div className={styles.toolbar}>
        <Button variant="primary" onClick={() => void initiativeApi.dispatch({ kind: 'next' })}>
          {t('initiative.next')}
        </Button>
        <div className={styles.addRow}>
          <Input
            value={manualName}
            onChange={setManualName}
            placeholder={t('initiative.manualPlaceholder')}
            onKeyDown={(e) => {
              if (e.key === 'Enter') {
                e.preventDefault();
                addManual();
              }
            }}
          />
          <Button variant="ghost" onClick={addManual}>
            {t('initiative.addManual')}
          </Button>
        </div>
      </div>

      <div className={styles.sectionLabel}>{t('initiative.queue')}</div>
      <div className={styles.queue} data-testid="initiative-queue">
        {orderEntries.length === 0 ? (
          <div className={styles.empty}>{t('initiative.queueEmpty')}</div>
        ) : (
          orderEntries.map((entry) => (
            <QueueSlot
              key={entry.id}
              entry={entry}
              active={state.activeId === entry.id}
              conditions={state.conditions[entry.id] ?? []}
              onSelect={() => void initiativeApi.dispatch({ kind: 'setActive', id: entry.id })}
              onRemove={() => void initiativeApi.dispatch({ kind: 'moveToReserve', id: entry.id })}
              onDragStart={(e) => {
                e.dataTransfer.setData(DND_MIME, entry.id);
                e.dataTransfer.effectAllowed = 'move';
              }}
              onDragOver={(e) => {
                e.preventDefault();
                e.dataTransfer.dropEffect = 'move';
              }}
              onDrop={(e) => reorderDrop(entry.id, e)}
              conditionsOpen={conditionsFor === entry.id}
              onToggleConditions={() =>
                setConditionsFor((cur) => (cur === entry.id ? null : entry.id))
              }
              onAddCondition={(conditionId) => {
                void initiativeApi.dispatch({ kind: 'addCondition', id: entry.id, conditionId });
                setConditionsFor(null);
              }}
              onRemoveCondition={(conditionId) => {
                void initiativeApi.dispatch({ kind: 'removeCondition', id: entry.id, conditionId });
              }}
            />
          ))
        )}
      </div>

      <div className={styles.sectionLabel}>{t('initiative.reserve')}</div>
      <div className={styles.reserve} data-testid="initiative-reserve">
        {reserveEntries.length === 0 ? (
          <div className={styles.empty}>{t('initiative.reserveEmpty')}</div>
        ) : (
          reserveEntries.map((entry) => (
            <div key={entry.id} className={styles.reserveRow}>
              <EntryAvatar entry={entry} />
              <span className={styles.reserveName}>{entry.name}</span>
              <Button
                variant="ghost"
                onClick={() => void initiativeApi.dispatch({ kind: 'restoreFromReserve', id: entry.id })}
              >
                {t('initiative.restore')}
              </Button>
              {entry.kind === 'manual' ? (
                <Button
                  variant="ghost"
                  onClick={() => void initiativeApi.dispatch({ kind: 'deleteEntry', id: entry.id })}
                >
                  {t('initiative.delete')}
                </Button>
              ) : null}
            </div>
          ))
        )}
      </div>
    </div>
  );
}