/**
 * 삭제·만료된 전략 ID — localStorage·ui_preferences·app-settings 정리
 */
import type { StrategyDto, AppSettingsDto } from './backendApi';
import { saveAppSettings } from './backendApi';
import {
  markStrategyMissingOnServer,
  reconcileStrategyMissingWithValidIds,
} from './strategyMissingCache';
import { getAppSettingsCache } from '../hooks/useAppSettings';
import { getUiPreferences, patchUiPreferences } from './uiPreferencesDb';
import type { UiPreferences } from '../types/uiPreferences';
import type { VirtualSessionConfig, VirtualTargetItem } from './virtualTradingStorage';

const LEGACY_TARGETS_KEY = 'gc_virtual_targets_v1';

function validStrategyIdSet(list: StrategyDto[]): Set<number> {
  return new Set(
    list.map(s => s.id).filter((id): id is number => id != null && id > 0),
  );
}

function readLegacyTargets(): VirtualTargetItem[] {
  try {
    const raw = localStorage.getItem(LEGACY_TARGETS_KEY);
    if (!raw) return [];
    const parsed = JSON.parse(raw) as VirtualTargetItem[];
    return Array.isArray(parsed) ? parsed : [];
  } catch {
    return [];
  }
}

function writeLegacyTargets(items: VirtualTargetItem[]): void {
  try {
    if (items.length === 0) localStorage.removeItem(LEGACY_TARGETS_KEY);
    else localStorage.setItem(LEGACY_TARGETS_KEY, JSON.stringify(items));
  } catch {
    /* ok */
  }
}

function sanitizeLegacyTargets(validIds: Set<number>): boolean {
  const legacy = readLegacyTargets();
  if (legacy.length === 0) return false;

  let changed = false;
  const next = legacy.map(t => {
    if (t.strategyId != null && t.strategyId > 0 && !validIds.has(t.strategyId)) {
      markStrategyMissingOnServer(t.strategyId);
      changed = true;
      return { ...t, strategyId: null };
    }
    return t;
  });

  if (changed) writeLegacyTargets(next);
  return changed;
}

function buildVirtualPatch(
  validIds: Set<number>,
): Partial<NonNullable<UiPreferences['virtual']>> | null {
  const ui = getUiPreferences();
  const virtual = ui.virtual;
  if (!virtual) return null;

  const patch: Partial<NonNullable<UiPreferences['virtual']>> = {};
  let changed = false;

  const session = virtual.session;
  const gid = session?.globalStrategyId;
  if (session && gid != null && gid > 0 && !validIds.has(gid)) {
    markStrategyMissingOnServer(gid);
    const nextSession: VirtualSessionConfig = {
      globalStrategyId: null,
      executionType: session.executionType === 'REALTIME_TICK' ? 'REALTIME_TICK' : 'CANDLE_CLOSE',
      positionMode: session.positionMode === 'SIGNAL_ONLY' ? 'SIGNAL_ONLY' : 'LONG_ONLY',
      running: session.running === true,
    };
    patch.session = nextSession;
    changed = true;
  }

  const targets = virtual.targets;
  if (targets?.length) {
    let targetsChanged = false;
    const nextTargets = targets.map(t => {
      if (t.strategyId != null && t.strategyId > 0 && !validIds.has(t.strategyId)) {
        markStrategyMissingOnServer(t.strategyId);
        targetsChanged = true;
        return { ...t, strategyId: null };
      }
      return t;
    });
    if (targetsChanged) {
      patch.targets = nextTargets;
      changed = true;
    }
  }

  return changed ? patch : null;
}

function buildAppSettingsPatch(validIds: Set<number>): AppSettingsDto | null {
  const cache = getAppSettingsCache();
  const sid = cache.liveStrategyId;
  if (sid == null || sid <= 0 || validIds.has(sid)) return null;

  markStrategyMissingOnServer(sid);
  return {
    liveStrategyId: null,
    liveStrategyCheck: false,
  };
}

/**
 * 전략 목록 로드 직후 호출 — stale ID 제거·missing 캐시 동기화
 */
export async function applyStrategyReferenceSanitize(strategies: StrategyDto[]): Promise<void> {
  const validIds = validStrategyIdSet(strategies);
  reconcileStrategyMissingWithValidIds(validIds);

  const legacyChanged = sanitizeLegacyTargets(validIds);
  const virtualPatch = buildVirtualPatch(validIds);
  const appPatch = buildAppSettingsPatch(validIds);

  if (virtualPatch) {
    patchUiPreferences({ virtual: virtualPatch }, true);
  }

  if (appPatch) {
    try {
      const saved = await saveAppSettings(appPatch);
      if (saved) Object.assign(getAppSettingsCache(), saved);
    } catch (e) {
      console.warn('[strategySanitize] app-settings 저장 실패:', e);
      Object.assign(getAppSettingsCache(), appPatch);
    }
  }

  if (legacyChanged || virtualPatch || appPatch) {
    console.info('[strategySanitize] 삭제된 전략 ID 참조를 정리했습니다.');
  }
}