/**
 * loop 的 Agent 回路 —— `AgentPort` 的实现(app 层装配,编码规范 §5.2)。
 *
 * 「回合由 usecase 驱动,**不放开自由 maxSteps**,预算在环外由 Harness 强制」——
 * 所以这里只做**一次**决断:把 Enabled 集与红绿灯喂给模型,要它在三型行动里选一个。
 *
 * 一切模型调用经 `ModelGateway`(两缝之一),replay 模式下自动走录制 —— 回放审看得见。
 * 见 docs/debt.md · M5-2:§6.1 规定这里用 Mastra `Agent`;当前直接经 ModelGateway,
 * 端口不变,换实现时 usecase 不动。
 */
import type { AgentAction, EnabledSet } from '@modules/loop-engine';
import type { ModelGateway } from '@modules/llm';
import type { TaskId } from '@contracts';

/** Agent 只能选三型行动之一(外加规划 / 弃用 / 评估 / 提交)—— schema 把它框住 */
const ACTION_SCHEMA = {
  type: 'object',
  required: ['kind'],
  properties: {
    kind: { enum: ['start', 'plan', 'disable', 'judge', 'tool', 'human', 'listen', 'submit'] },
    itemId: { type: 'string' },
    tool: { type: 'string' },
    input: { type: 'object' },
    workOrder: { enum: ['execution', 'acceptance'] },
    card: { type: 'object' },
    eventType: { enum: ['data', 'time'] },
    keyFilter: { type: 'object' },
    deadline: { type: 'string' },
    criterion: { type: 'string' },
    satisfied: { type: 'boolean' },
    rationale: { type: 'string' },
    reason: { type: 'string' },
  },
} as const;

export type AgentRunnerDeps = {
  readonly gateway: ModelGateway;
  /** 活动声明的自定义模型名 */
  readonly modelOf: (taskId: TaskId) => Promise<string>;
};

export function createAgentRunner(deps: AgentRunnerDeps): {
  decide(input: { taskId: TaskId; narrative: string; enabled: EnabledSet; scope: Record<string, unknown> }): Promise<AgentAction>;
} {
  return {
    async decide({ taskId, narrative, enabled, scope }) {
      // 交集为空即断点 —— 引擎已经算好了,这里只把它讲给模型听
      const breakpoint = enabled.entries.length === 0;

      const prompt = [
        '你是这一单任务的案例工作者。下面是语义引擎发布的**当下可为**与**目标缺口**。',
        '你只能选一个行动,且必须落在三型行动之内:调工具 / 调人 / 立监听(外加 start、plan、disable、judge、submit)。',
        '规矩:①触达世界的动作只能 tool(写类会被登记为动作意向,放行时才落地)',
        '②缺口只有人知道 → human;缺口在世界侧 → listen(必须给 deadline,ISO-8601)',
        '③成果已齐才 submit。只输出 JSON。',
        '',
        `【案例说明书与活动记忆】\n${narrative}`,
        '',
        `【当下可为(Enabled 集)】\n${
          enabled.entries.map((e) => `- ${e.id} ${e.name}(${e.type}${e.requiresManualStart ? ' · 须你启动' : ''}${e.discretionary ? ' · 裁量项' : ''})`).join('\n') || '(空)'
        }`,
        `【目标缺口】\n${enabled.gaps.join('、') || '(无)'}`,
        enabled.judgements.length === 0
          ? ''
          : `【待你评估的语义性前提】\n${enabled.judgements.map((j) => `- ${j.criterion}:${j.statement}`).join('\n')}`,
        breakpoint ? '【注意】当下可为 ∩ 目标所需 = 空 —— 这是依赖断点,请调人或立监听。' : '',
        `【任务数据】\n${JSON.stringify(scope).slice(0, 4000)}`,
      ]
        .filter((line) => line !== '')
        .join('\n');

      const model = await deps.modelOf(taskId);
      const result = await deps.gateway.generate({
        model,
        prompt,
        outputSchema: ACTION_SCHEMA,
        taskId,
        label: 'loop-turn',
      });

      return normalize(result.object, enabled);
    },
  };
}

/** 模型出参归一为 AgentAction;不合规一律退化为「立监听等人」而不是乱动世界 */
function normalize(object: unknown, enabled: EnabledSet): AgentAction {
  const raw = (object ?? {}) as Record<string, unknown>;
  const kind = String(raw['kind'] ?? '');
  const itemId = String(raw['itemId'] ?? enabled.entries[0]?.id ?? '');

  switch (kind) {
    case 'start':
    case 'plan':
      return { kind: kind as 'start' | 'plan', itemId };
    case 'disable':
      return { kind: 'disable', itemId, reason: String(raw['reason'] ?? '此单不走这条') };
    case 'judge':
      return {
        kind: 'judge',
        criterion: String(raw['criterion'] ?? ''),
        satisfied: raw['satisfied'] === true,
        rationale: String(raw['rationale'] ?? ''),
      };
    case 'tool':
      return {
        kind: 'tool',
        itemId,
        tool: String(raw['tool'] ?? ''),
        input: (raw['input'] ?? {}) as Record<string, unknown>,
      };
    case 'human':
      return {
        kind: 'human',
        itemId,
        card: (raw['card'] ?? {}) as Record<string, unknown>,
        workOrder: raw['workOrder'] === 'acceptance' ? 'acceptance' : 'execution',
      };
    case 'listen':
      return {
        kind: 'listen',
        itemId,
        eventType: raw['eventType'] === 'time' ? 'time' : 'data',
        keyFilter: (raw['keyFilter'] ?? {}) as Record<string, string>,
        // 时限必配 —— 模型没给就按三天兜底,绝不留幽灵等待
        deadline: typeof raw['deadline'] === 'string' && /^P/.test(raw['deadline']) ? raw['deadline'] : 'P3D',
      };
    case 'submit':
      return { kind: 'submit', rationale: String(raw['rationale'] ?? '判据已收敛') };
    default:
      // 看不懂就等人,不擅自触达世界
      return {
        kind: 'human',
        itemId,
        card: { title: '需要你判断下一步', reason: '模型未给出合规的行动' },
        workOrder: 'execution',
      };
  }
}