import {
  isStrategyMissingOnServer,
  loadStrategy,
  loadStrategyTimeframes,
  repairStrategyTimeframes,
  saveStrategy,
  type StrategyDto,
} from './backendApi';
import {
  alignBuySellStartCandleTypesForSave,
  collectDslBranches,
  collectTimeframesFromEditorState,
  decodeConditionForEditor,
  encodeConditionForSave,
  mergeStartMetaForLoad,
  normalizeStartCombineOp,
  syncEditorStateCandleTypesForSave,
  type EditorConditionState,
} from './strategyConditionSerde';
import { getStartCandleTypes, normalizeStartCandleType } from './strategyStartNodes';
import type { LogicNode } from './strategyTypes';
import type { StrategyFlowLayoutStore } from './strategyEditorLayoutStorage';

function collectFromFlowLayout(layout: StrategyFlowLayoutStore | null | undefined): string[] {
  if (!layout) return [];
  const set = new Set<string>();
  for (const side of ['buy', 'sell'] as const) {
    const metaMap = layout[side]?.startMeta;
    if (!metaMap) continue;
    for (const meta of Object.values(metaMap)) {
      for (const ct of getStartCandleTypes(meta)) set.add(normalizeStartCandleType(ct));
    }
  }
  return [...set];
}

function collectFromStrategyDto(strategy: StrategyDto | null | undefined): string[] {
  if (!strategy) return [];
  const set = new Set<string>();
  const buy = strategy.buyCondition as LogicNode | null | undefined;
  const sell = strategy.sellCondition as LogicNode | null | undefined;
  for (const b of [
    ...collectDslBranches(buy ?? null),
    ...collectDslBranches(sell ?? null),
  ]) {
    const types = b.candleTypes?.length ? b.candleTypes : [b.candleType];
    for (const ct of types) set.add(normalizeStartCandleType(ct));
  }
  return [...set];
}

/** 편집기·flow layout·전략 DTO에서 UI 평가 분봉 수집 */
export function collectUiEvaluationTimeframes(
  _strategyId: number,
  strategy?: StrategyDto | null,
  editorState?: { buy: EditorConditionState; sell: EditorConditionState },
): string[] {
  if (editorState) {
    const fromEditor = [
      ...collectTimeframesFromEditorState(editorState.buy),
      ...collectTimeframesFromEditorState(editorState.sell),
    ].map(normalizeStartCandleType);
    if (fromEditor.length > 0) return [...new Set(fromEditor)];
  }
  const fromLayout = collectFromFlowLayout(strategy?.flowLayout);
  if (fromLayout.length > 0) return fromLayout;
  return collectFromStrategyDto(strategy);
}

function evaluationTimeframesMatch(uiTfs: string[], serverTfs: string[]): boolean {
  const uiSet = new Set(uiTfs.map(tf => normalizeStartCandleType(tf)));
  const serverSet = new Set(serverTfs.map(tf => normalizeStartCandleType(tf)));
  const missingOnServer = uiTfs.some(tf => !serverSet.has(normalizeStartCandleType(tf)));
  const extraOnServer = [...serverSet].some(tf => !uiSet.has(tf));
  if (!missingOnServer && !extraOnServer) return true;
  if (uiSet.size === 1 && uiSet.has('1m') && serverSet.size === 1 && serverSet.has('1m')) {
    return true;
  }
  return false;
}

/**
 * UI 분봉과 서버 DSL 불일치 시 자동 동기화 시도 후, 여전히 다르면 안내.
 * @returns false — 진행 불가(저장 필요)
 */
export async function warnStrategyTimeframeMismatch(
  strategyId: number,
  strategy?: StrategyDto | null,
  editorState?: { buy: EditorConditionState; sell: EditorConditionState },
): Promise<boolean> {
  const strat = strategy ?? await loadStrategy(strategyId);
  const uiTfs = collectUiEvaluationTimeframes(strategyId, strat, editorState);
  if (uiTfs.length === 0) return true;

  let serverTfs: string[];
  try {
    serverTfs = await loadStrategyTimeframes(strategyId);
  } catch {
    return true;
  }

  if (evaluationTimeframesMatch(uiTfs, serverTfs)) return true;

  const synced = await syncStrategyTimeframesFromLayoutIfNeeded(strategyId, strat);
  if (synced) {
    try {
      serverTfs = await loadStrategyTimeframes(strategyId);
      if (evaluationTimeframesMatch(uiTfs, serverTfs)) return true;
    } catch {
      return true;
    }
  }

  const uiSet = new Set(uiTfs.map(tf => normalizeStartCandleType(tf)));
  const serverSet = new Set(serverTfs.map(tf => normalizeStartCandleType(tf)));
  const uiLabel = uiTfs.map(tf => normalizeStartCandleType(tf)).join(', ') || '1m';
  const serverLabel = [...serverSet].join(', ') || '1m';
  if (uiSet.size === serverSet.size && [...uiSet].every(tf => serverSet.has(tf))) {
    return true;
  }

  window.alert(
    `전략 화면에는 ${uiLabel} 봉으로 설정되어 있지만, 서버에는 ${serverLabel} 만 저장되어 있습니다.\n\n`
    + '전략편집기에서 「저장」을 누르거나 START 분봉을 다시 선택해 DB에 반영한 뒤 실시간 체크를 켜 주세요.',
  );
  return false;
}

function buildEditorStateFromStrategy(
  strategy: StrategyDto,
  layout: StrategyFlowLayoutStore | null | undefined,
  side: 'buy' | 'sell',
): EditorConditionState {
  const decoded = decodeConditionForEditor(
    (side === 'buy' ? strategy.buyCondition : strategy.sellCondition) as LogicNode | null,
  );
  const snap = layout?.[side];
  const merged: EditorConditionState = {
    root: decoded.root,
    startMeta: mergeStartMetaForLoad(decoded.startMeta, snap?.startMeta),
    extraStartIds: snap?.extraStartIds?.length ? snap.extraStartIds : decoded.extraStartIds,
    extraRoots: snap?.extraRoots ?? decoded.extraRoots,
    startCombineOp: normalizeStartCombineOp(snap?.startCombineOp ?? decoded.startCombineOp),
  };
  return syncEditorStateCandleTypesForSave(merged);
}

/**
 * DB flow layout의 START 분봉이 서버 DSL과 다르면 자동 동기화.
 */
export async function syncStrategyTimeframesFromLayoutIfNeeded(
  strategyId: number,
  _strategy?: StrategyDto | null,
): Promise<boolean> {
  if (isStrategyMissingOnServer(strategyId)) return false;
  const strat = await loadStrategy(strategyId);
  if (!strat) return false;

  const uiTfs = collectUiEvaluationTimeframes(strategyId, strat);
  if (uiTfs.length === 0) return true;

  let serverTfs: string[];
  try {
    serverTfs = await loadStrategyTimeframes(strategyId);
  } catch {
    return true;
  }

  if (evaluationTimeframesMatch(uiTfs, serverTfs)) return true;

  const layout = strat.flowLayout;
  if (!layout) {
    const repaired = await repairStrategyTimeframes(strategyId);
    if (!repaired) return false;
    const tfs = await loadStrategyTimeframes(strategyId);
    return evaluationTimeframesMatch(uiTfs, tfs);
  }

  const buyState = buildEditorStateFromStrategy(strat, layout, 'buy');
  const sellState = buildEditorStateFromStrategy(strat, layout, 'sell');

  await persistStrategyEvaluationTimeframes(
    strategyId,
    strat.name,
    strat.description ?? '',
    buyState,
    sellState,
    layout,
  );
  try {
    await repairStrategyTimeframes(strategyId);
  } catch {
    /* repair optional */
  }
  return true;
}

/** 편집기 상태(DSL + flow layout)를 DB에 저장 — 실시간 평가 캐시는 서버에서 무효화됨 */
export async function persistStrategyEditorState(
  strategyId: number,
  name: string,
  description: string,
  buy: EditorConditionState,
  sell: EditorConditionState,
  flowLayout: StrategyFlowLayoutStore,
): Promise<StrategyDto> {
  const aligned = alignBuySellStartCandleTypesForSave(buy, sell);
  const encodedBuy = encodeConditionForSave(aligned.buy);
  const encodedSell = encodeConditionForSave(aligned.sell);
  const saved = await saveStrategy({
    id: strategyId,
    name,
    description,
    buyCondition: encodedBuy,
    sellCondition: encodedSell,
    flowLayout,
    enabled: true,
  });
  if (typeof window !== 'undefined') {
    window.dispatchEvent(new CustomEvent('gc:strategy-saved', {
      detail: { strategyId, buyCondition: encodedBuy, sellCondition: encodedSell, flowLayout },
    }));
  }
  return saved;
}

/** @deprecated persistStrategyEditorState 사용 */
export async function persistStrategyEvaluationTimeframes(
  strategyId: number,
  name: string,
  description: string,
  buy: EditorConditionState,
  sell: EditorConditionState,
  flowLayout?: StrategyFlowLayoutStore,
): Promise<void> {
  if (!flowLayout) return;
  await persistStrategyEditorState(strategyId, name, description, buy, sell, flowLayout);
}

export type { StrategyFlowLayoutStore };