import type {
  RuntimeStoryActionResponse,
  RuntimeStoryChoicePayload,
  RuntimeStoryOptionView,
  ServerRuntimeFunctionId,
  Task5RuntimeFunctionId,
} from '../../packages/shared/src/contracts/story';
import {
  SERVER_RUNTIME_FUNCTION_IDS,
  TASK5_RUNTIME_FUNCTION_IDS,
} from '../../packages/shared/src/contracts/story';
import { rehydrateSavedSnapshot } from '../persistence/runtimeSnapshot';
import type {
  HydratedGameState,
  HydratedSavedGameSnapshot,
} from '../persistence/runtimeSnapshotTypes';
import type { GameState, StoryMoment, StoryOption } from '../types';
import { AnimationState } from '../types';
import { type ApiRetryOptions, requestJson } from './apiClient';

const RUNTIME_STORY_API_BASE = '/api/runtime/story';
const DEFAULT_SESSION_ID = 'runtime-main';
const RUNTIME_STORY_RETRY: ApiRetryOptions = {
  maxRetries: 1,
  baseDelayMs: 220,
  maxDelayMs: 640,
  retryUnsafeMethods: true,
};

const TASK5_RUNTIME_FUNCTION_ID_SET = new Set<string>(
  TASK5_RUNTIME_FUNCTION_IDS,
);
const SERVER_RUNTIME_FUNCTION_ID_SET = new Set<string>([
  ...SERVER_RUNTIME_FUNCTION_IDS,
]);

export type RuntimeStoryServiceOptions = {
  signal?: AbortSignal;
  retry?: ApiRetryOptions;
};

export type RuntimeStoryResponse = RuntimeStoryActionResponse<
  HydratedGameState,
  StoryMoment
>;
export type { RuntimeStoryChoicePayload };

function requestRuntimeStoryJson<T>(
  path: string,
  init: RequestInit,
  fallbackMessage: string,
  options: RuntimeStoryServiceOptions = {},
) {
  return requestJson<T>(
    `${RUNTIME_STORY_API_BASE}${path}`,
    {
      ...init,
      signal: options.signal,
    },
    fallbackMessage,
    { retry: options.retry ?? RUNTIME_STORY_RETRY },
  );
}

function createRuntimeStoryOption(
  option: RuntimeStoryOptionView,
  _gameState?: Pick<GameState, 'currentEncounter'>,
): StoryOption {
  return {
    functionId: option.functionId,
    actionText: option.actionText,
    text: option.actionText,
    detailText: option.detailText,
    visuals: {
      playerAnimation: AnimationState.IDLE,
      playerMoveMeters: 0,
      playerOffsetY: 0,
      playerFacing: 'right',
      scrollWorld: false,
      monsterChanges: [],
    },
    interaction: option.interaction as StoryOption['interaction'] | undefined,
    runtimePayload: option.payload,
    disabled: option.disabled,
    disabledReason: option.reason,
  };
}

export function getRuntimeSessionId(
  gameState: Pick<GameState, 'runtimeSessionId'>,
) {
  return gameState.runtimeSessionId?.trim() || DEFAULT_SESSION_ID;
}

export function getRuntimeClientVersion(
  gameState: Pick<GameState, 'runtimeActionVersion'>,
) {
  return typeof gameState.runtimeActionVersion === 'number'
    ? gameState.runtimeActionVersion
    : undefined;
}

export function isTask5RuntimeFunctionId(
  functionId: string,
): functionId is Task5RuntimeFunctionId {
  return TASK5_RUNTIME_FUNCTION_ID_SET.has(functionId);
}

export function isServerRuntimeFunctionId(
  functionId: string,
): functionId is ServerRuntimeFunctionId {
  return SERVER_RUNTIME_FUNCTION_ID_SET.has(functionId);
}

export function shouldUseServerRuntimeOptions(options: StoryOption[] | null) {
  return Boolean(
    options?.length &&
      options.every((option) => isServerRuntimeFunctionId(option.functionId)),
  );
}

export function buildStoryMomentFromRuntimeOptions(params: {
  storyText: string;
  options: RuntimeStoryOptionView[];
  gameState?: Pick<GameState, 'currentEncounter'>;
}): StoryMoment {
  return {
    text: params.storyText,
    options: params.options.map((option) =>
      createRuntimeStoryOption(option, params.gameState),
    ),
  } satisfies StoryMoment;
}

function shouldPreferSnapshotStory(story: StoryMoment | null) {
  return Boolean(
    story &&
      (story.displayMode === 'dialogue' ||
        story.deferredOptions?.length ||
        story.dialogue?.length),
  );
}

export function resolveRuntimeStoryMoment(params: {
  response: RuntimeStoryResponse;
  hydratedSnapshot: HydratedSavedGameSnapshot;
  fallbackGameState?: Pick<GameState, 'currentEncounter'>;
  fallbackStoryText?: string;
}) {
  if (shouldPreferSnapshotStory(params.hydratedSnapshot.currentStory)) {
    return params.hydratedSnapshot.currentStory!;
  }

  const options =
    params.response.viewModel.availableOptions.length > 0
      ? params.response.viewModel.availableOptions
      : params.response.presentation.options;

  return buildStoryMomentFromRuntimeOptions({
    storyText:
      params.response.presentation.storyText ||
      params.hydratedSnapshot.currentStory?.text ||
      params.fallbackStoryText ||
      '',
    options,
    gameState: params.hydratedSnapshot.gameState.currentEncounter
      ? params.hydratedSnapshot.gameState
      : params.fallbackGameState,
  });
}

export async function getRuntimeStoryState(
  sessionId: string,
  options: RuntimeStoryServiceOptions = {},
) {
  const response = await requestRuntimeStoryJson<RuntimeStoryResponse>(
    `/state/${encodeURIComponent(sessionId || DEFAULT_SESSION_ID)}`,
    { method: 'GET' },
    '读取运行时故事状态失败',
    options,
  );

  return {
    ...response,
    snapshot: rehydrateSavedSnapshot(
      response.snapshot as HydratedSavedGameSnapshot,
    ),
  } satisfies RuntimeStoryResponse;
}

export async function resolveRuntimeStoryAction(
  params: {
    sessionId?: string;
    clientVersion?: number;
    option: Pick<StoryOption, 'functionId' | 'actionText'>;
    targetId?: string;
    payload?: RuntimeStoryChoicePayload;
  },
  options: RuntimeStoryServiceOptions = {},
) {
  const response = await requestRuntimeStoryJson<RuntimeStoryResponse>(
    '/actions/resolve',
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        sessionId: params.sessionId || DEFAULT_SESSION_ID,
        clientVersion: params.clientVersion,
        action: {
          type: 'story_choice',
          functionId: params.option.functionId,
          targetId: params.targetId,
          payload: {
            optionText: params.option.actionText,
            ...(params.payload ?? {}),
          },
        },
      }),
    },
    '执行运行时动作失败',
    options,
  );

  return {
    ...response,
    snapshot: rehydrateSavedSnapshot(
      response.snapshot as HydratedSavedGameSnapshot,
    ),
  } satisfies RuntimeStoryResponse;
}

export function getRuntimeActionSnapshot(response: RuntimeStoryResponse) {
  return rehydrateSavedSnapshot(response.snapshot as HydratedSavedGameSnapshot);
}