import type { IndicatorConfig } from '../types';
import { layoutKey } from './indicatorPaneMerge';

export type IndicatorChartSyncMode =
  | 'none'
  | 'remove-only'
  | 'add-only'
  | 'params-changed'
  | 'reorder-only'
  | 'layout-changed'
  | 'full';

export interface IndicatorChartChange {
  mode: IndicatorChartSyncMode;
  removedIds: string[];
  added: IndicatorConfig[];
  paramsChangedIds: string[];
}

export function singleIndParamKey(i: IndicatorConfig): string {
  return `${JSON.stringify(i.params)}|${(i.plots ?? []).map(p => p.id).sort().join(',')}|${i.mergedWith ?? ''}`;
}

/** 차트에 로드된 지표 id 중 현재 설정에 없는(이전 탭 잔존) 항목이 있는지 */
export function chartHasStaleIndicators(
  loadedIds: Set<string>,
  indicators: IndicatorConfig[],
): boolean {
  if (loadedIds.size === 0) return false;
  const expected = new Set(
    indicators.filter(i => i.hidden !== true).map(i => i.id),
  );
  for (const id of loadedIds) {
    if (!expected.has(id)) return true;
  }
  return false;
}

/** 이전·현재 지표 목록 차이를 분류해 최소 갱신 경로를 선택 */
export function classifyIndicatorChartChange(
  prev: IndicatorConfig[],
  curr: IndicatorConfig[],
): IndicatorChartChange {
  const prevMap = new Map(prev.map(i => [i.id, i]));
  const currMap = new Map(curr.map(i => [i.id, i]));

  const removedIds = prev.filter(i => !currMap.has(i.id)).map(i => i.id);
  const added = curr.filter(i => !prevMap.has(i.id));

  const paramsChangedIds: string[] = [];
  for (const c of curr) {
    const p = prevMap.get(c.id);
    if (!p) continue;
    if (singleIndParamKey(p) !== singleIndParamKey(c)) {
      paramsChangedIds.push(c.id);
    }
  }

  const empty: IndicatorChartChange = {
    mode: 'none',
    removedIds,
    added,
    paramsChangedIds,
  };

  if (removedIds.length === 0 && added.length === 0 && paramsChangedIds.length === 0) {
    if (layoutKey(prev) !== layoutKey(curr)) {
      return { ...empty, mode: 'layout-changed' };
    }
    const sameSet = prev.length === curr.length
      && prev.every(p => currMap.has(p.id));
    if (sameSet && prev.map(i => i.id).join(',') !== curr.map(i => i.id).join(',')) {
      return { ...empty, mode: 'reorder-only' };
    }
    return empty;
  }

  /** 병합·분리 등 mergedWith 변경 — params 키에도 잡히지만 pane 재배치가 필요 */
  if (
    removedIds.length === 0
    && added.length === 0
    && layoutKey(prev) !== layoutKey(curr)
  ) {
    return { ...empty, mode: 'layout-changed', paramsChangedIds };
  }

  if (removedIds.length > 0 && added.length === 0 && paramsChangedIds.length === 0) {
    return { ...empty, mode: 'remove-only' };
  }

  if (added.length > 0 && removedIds.length === 0 && paramsChangedIds.length === 0) {
    return { ...empty, mode: 'add-only' };
  }

  if (
    paramsChangedIds.length > 0
    && removedIds.length === 0
    && added.length === 0
  ) {
    return { ...empty, mode: 'params-changed' };
  }

  return { ...empty, mode: 'full' };
}