/**
 * loop 回合驱动 —— 语义引擎 × Agent 回路(编码规范 §5.3 / §6.3;语义出处 AM 04)。
 *
 * 定位 → 择向 → 决断 → 行动 → 写数据 → 回到定位。
 * **回合由 usecase 驱动,不放开自由 maxSteps;预算在环外由 Harness 强制。**
 */
import type { LoopModel, TaskId } from '@contracts';
import type { AgentAction, LoopEngineService, TurnOutcome } from '../../contract.ts';
import { ForbiddenTerminalError } from '../../contract.ts';
import type {
  AgentPort,
  CardGateway,
  Clock,
  ListenerRegistrar,
  LoopStateStore,
  MemoryRecorder,
  SkillGateway,
  ViewGateway,
  Sfeel,
  TaskContext,
  TaskDataGateway,
  ToolGateway,
} from '../../port.ts';
import { parseCmmn } from '../domain/cmmn-parse.ts';
import type { CaseRuntime } from '../domain/lifecycle.ts';
import {
  autoCompleteReady,
  initialRuntime,
  navigate,
  occur,
  publishEnabled,
  reenter as reenterItem,
  transitionItem,
} from '../domain/lifecycle.ts';
import { evaluateTable, evaluationOrder } from '../domain/dmn.ts';

export type TurnRunnerDeps = {
  readonly state: LoopStateStore;
  readonly sfeel: Sfeel;
  readonly data: TaskDataGateway;
  readonly agent: AgentPort;
  readonly tools: ToolGateway;
  readonly cards: CardGateway;
  readonly listeners: ListenerRegistrar;
  readonly memory: MemoryRecorder;
  readonly views: ViewGateway;
  readonly skills: SkillGateway;
  readonly tasks: TaskContext;
  readonly clock: Clock;
};

export function createTurnRunner(deps: TurnRunnerDeps): LoopEngineService {
  async function loaded(taskId: TaskId) {
    const found = await deps.state.load(taskId);
    if (found === undefined) throw new Error(`loop 未装载:${taskId}`);
    return found;
  }

  /** 变化面:任务视图里有值的键 —— onPart 的「件到」判据 */
  function changedRefs(scope: Record<string, unknown>): Set<string> {
    return new Set(Object.keys(scope).filter((k) => scope[k] !== undefined && scope[k] !== null));
  }

  async function publishFor(taskId: TaskId) {
    const { model, parsed, runtime } = await loaded(taskId);
    const scope = await deps.data.view(taskId);
    const gaps = parsed.items
      .filter((i) => !i.discretionary && runtime.items.find((r) => r.id === i.id)?.state !== 'Completed')
      .map((i) => i.name);
    return {
      model,
      parsed,
      runtime,
      scope,
      enabled: publishEnabled(parsed, runtime, scope, changedRefs(scope), deps.sfeel.condition, gaps),
    };
  }

  async function applyAction(taskId: TaskId, action: AgentAction, runtime: CaseRuntime): Promise<{ runtime: CaseRuntime; status: TurnOutcome['status']; reason?: string }> {
    const context = await deps.tasks.of(taskId);

    switch (action.kind) {
      case 'start': {
        // manualStart —— 进入 Active 永远出自 Agent 的裁量启动,留痕
        await deps.memory.append({
          taskId,
          kind: 'engine-transition',
          title: `manualStart:${action.itemId}`,
          detail: { by: 'agent' },
        });
        return { runtime: transitionItem(runtime, action.itemId, 'Active'), status: 'running' };
      }

      case 'plan': {
        await deps.memory.append({ taskId, kind: 'engine-transition', title: `规划裁量项入场:${action.itemId}` });
        return { runtime: transitionItem(runtime, action.itemId, 'Enabled'), status: 'running' };
      }

      case 'disable': {
        await deps.memory.append({
          taskId,
          kind: 'engine-transition',
          title: `弃用计划项:${action.itemId}`,
          detail: { reason: action.reason },
        });
        return { runtime: transitionItem(runtime, action.itemId, 'Disabled'), status: 'running' };
      }

      case 'judge': {
        // 语义性前提的裁量评估 —— 评估留痕,可回放可归因
        await deps.memory.append({
          taskId,
          kind: 'evaluation',
          title: `语义性前提评估:${action.criterion} → ${action.satisfied ? '满足' : '未满足'}`,
          detail: { rationale: action.rationale },
        });
        return { runtime, status: 'running' };
      }

      case 'tool': {
        // 先验迁移再动手:不合法的行动不该在世界上留下痕迹(登记意向、调工具都算)
        const done = transitionItem(runtime, action.itemId, 'Completed');
        // 写类工具登记为动作意向 —— 触达世界的动作集中在放行时落地
        if (await deps.tools.isWriteEffect(action.tool)) {
          await deps.tools.registerIntent({
            taskId,
            tool: action.tool,
            input: action.input,
            label: `${action.itemId}:${action.tool}`,
          });
          return { runtime: done, status: 'running' };
        }
        const result = await deps.tools.invoke({
          tool: action.tool,
          input: action.input,
          activityId: context.activityId,
          taskId,
        });
        await deps.memory.append({
          taskId,
          kind: 'result',
          title: `${action.tool} ${result.ok ? '返回' : '失败'}`,
          detail: { output: result.output, error: result.error?.message },
        });
        return {
          runtime: result.ok ? done : transitionItem(runtime, action.itemId, 'Failed'),
          status: 'running',
        };
      }

      case 'human': {
        /*
         * 调人 = 立监听听人:调用即 Active(阻塞),回传驱动前提。
         *
         * **先验迁移,再发卡**:迁移非法时抛在前面,世界上不会留下一张已发出的卡。
         * 反过来写(先发卡后迁移)会让每一次被拒的回合都白发一张卡 —— 卡收不回,
         * 负责人的工作台上就堆起一摞谁也不知道该怎么答的「请处理」。
         */
        const advanced = transitionItem(runtime, action.itemId, 'Active');
        const card = await deps.cards.issue({
          taskId,
          ownerId: context.ownerId,
          humanCallCap: context.humanCallCap,
          workOrder: action.workOrder,
          card: action.card,
        });
        await deps.listeners.register({
          taskId,
          eventType: 'human',
          keyFilter: { cardId: card.id },
          deadline: 'P3D',
        });
        return { runtime: advanced, status: 'awaiting' };
      }

      case 'listen': {
        // AI 不能调用世界:对世界只有两种合法姿势 —— 触达它(动作)与等它(监听)
        await deps.listeners.register({
          taskId,
          eventType: action.eventType,
          keyFilter: action.keyFilter,
          deadline: action.deadline,
        });
        await deps.memory.append({
          taskId,
          kind: 'engine-transition',
          title: `立监听:${action.eventType}(时限 ${action.deadline})`,
          detail: action.keyFilter,
        });
        return { runtime, status: 'awaiting' };
      }

      case 'submit': {
        await deps.memory.append({
          taskId,
          kind: 'thought',
          title: '判定成果已齐,提交放行',
          detail: { rationale: action.rationale },
        });
        // 终局唯放行:引擎不把案计划置为 Completed —— 那是 release 的事
        return { runtime, status: 'submitted' };
      }
    }
  }

  return {
    async load(taskId, model: LoopModel) {
      const parsed = parseCmmn(model.cmmnXml);
      const runtime = initialRuntime(parsed);
      await deps.state.save(taskId, model, parsed, runtime);
      await deps.memory.append({
        taskId,
        kind: 'engine-transition',
        title: `装载案例模型:${parsed.name}(${parsed.items.length} 个计划项)`,
      });
      return runtime;
    },

    async runtime(taskId) {
      return (await deps.state.load(taskId))?.runtime;
    },

    async publish(taskId) {
      return (await publishFor(taskId)).enabled;
    },

    /** 一个回合:定位 → 择向 → 决断 → 行动 → 写数据 */
    async runTurn(taskId): Promise<TurnOutcome> {
      const { model, parsed, runtime, scope, enabled } = await publishFor(taskId);

      // 齐了即收:必做项完成且无进行中项 → 提交放行(仍必经放行卡)
      if (autoCompleteReady(parsed, runtime)) {
        return { runtime, enabled, navigation: { kind: 'converged' }, status: 'submitted' };
      }

      // 导航即交集:当下可为 ∩ 目标所需
      const navigation = navigate(enabled, new Set(enabled.entries.map((e) => e.id)));
      if (navigation.kind === 'breakpoint') {
        // 断点即人环 —— 由 Agent 定夺调人还是立监听,判定留痕
        await deps.memory.append({
          taskId,
          kind: 'thought',
          title: '依赖断点:当下可为 ∩ 目标所需 = 空',
          detail: { gaps: navigation.gaps },
        });
      }

      const activityId = (await deps.tasks.of(taskId)).activityId;
      const catalog = await deps.skills.index(activityId);

      /*
       * 叙事面 = 案例说明书 + 活动记忆选摘 + **技能目录**。
       * 渐进披露(AM 08):常驻上下文只给「有哪些方法、何时适用」,
       * 正文与知识引用等 AI 说要才加载 —— 一次把所有正文塞进去,
       * 上下文会被方法论淹掉,真正的局面反而看不见。
       */
      const narrative = [
        model.narrative,
        ...(await deps.memory.loadActivityMemory(activityId, 20)).map((m) => `[${m.layer}] ${m.statement}`),
        catalog.length === 0
          ? ''
          : `【可装配的技能(目录)】\n${catalog.map((s) => `- ${s.id} ${s.label}:${s.applicability}`).join('\n')}`,
      ]
        .filter((line) => line !== '')
        .join('\n\n');

      // 装配入信封:这一回合手上有哪些技能及其版本,记进任务记忆 —— 回放与归因依赖之
      if (catalog.length > 0) {
        const stamp = await deps.skills.stamp(activityId, catalog.map((s) => s.id));
        await deps.memory.append({
          taskId,
          kind: 'thought',
          title: `装配技能:${stamp.map((s) => `${s.id}@${s.version}`).join('、')}`,
          detail: { skills: [...stamp] },
        });
      }

      const action = await deps.agent.decide({ taskId, narrative, enabled, scope });

      // AI 不得产生终局迁移
      if (action.kind === 'start') {
        const item = parsed.items.find((i) => i.id === action.itemId);
        if (item === undefined) throw new ForbiddenTerminalError('owner');
      }

      /*
       * AI 提的行动可能**不合法**(违反生命周期迁移拓扑、越权、预算触顶)。
       * 引擎拒绝它是对的 —— 「语义忠实:引擎不得私改迁移拓扑」;但**不能因此死掉**:
       * 抛出去会让这一回合的副作用(卡已发出)留在世界上、运行时却没落笔,
       * 推进器于是一遍遍重来,每遍再发一张卡。
       *
       * 正确做法:拒绝 + 留痕 + 把拒绝理由喂回下一回合的上下文。
       * AI 提出非法行动是预期内的事,引擎的职责是不执行,不是崩掉。
       * 反复提不出合法行动由 Harness 兜底(步预算与停滞熔断),那才是它该管的事。
       */
      let applied: { runtime: CaseRuntime; status: TurnOutcome['status']; reason?: string };
      try {
        applied = await applyAction(taskId, action, runtime);
      } catch (error) {
        const reason = error instanceof Error ? error.message : String(error);
        await deps.memory.append({
          taskId,
          kind: 'result',
          title: `行动被拒:${reason}`,
          detail: { action, hint: '请在「当下可为」里另选一项,或改用调人 / 立监听' },
        });
        return { runtime, enabled, navigation, action, status: 'running' };
      }
      await deps.state.save(taskId, model, parsed, applied.runtime);

      /*
       * 每回合推一次案例全景 —— 呈现是投影,失败只丢这一帧,不影响回路推进。
       * 画面的素材全部来自语义引擎(阶段态 / 当下可为 / 缺口),零 LLM。
       */
      try {
        await deps.views.push({
          taskId,
          activityId: (await deps.tasks.of(taskId)).activityId,
          template: 'case-overview',
          scope: {
            ...scope,
            'case:stages': parsed.items
              .filter((i) => i.type === 'stage')
              .map((i) => ({ name: i.name, state: applied.runtime.items.find((r) => r.id === i.id)?.state ?? '—' })),
            'case:enabled': enabled.entries.map((e) => ({ name: e.name, state: e.requiresManualStart ? '待启动' : '可进行' })),
            'case:gaps': enabled.gaps.map((g) => ({ name: g, state: '未满足' })),
            gapCount: enabled.gaps.length,
            enabledCount: enabled.entries.length,
            activeStage: enabled.activeStages.join('、') || '—',
          },
        });
      } catch {
        // 呈现失败不影响回路:画面丢一帧,事实一件不少
      }

      return {
        runtime: applied.runtime,
        enabled,
        navigation,
        action,
        status: applied.status,
        ...(applied.reason === undefined ? {} : { blockedReason: applied.reason }),
      };
    },

    /** 事件驱动续跑:挂起期间事件不丢,恢复即补投 */
    async onEvent(taskId, event) {
      const { model, parsed, runtime } = await loaded(taskId);
      await deps.memory.append({
        taskId,
        kind: 'observation',
        title: `事件到达(${event.kind}):${event.ref}`,
        detail: event.payload,
      });

      let next = runtime;
      // 里程碑与事件监听器只有一条主迁移:Available →(occur)→ Completed
      const listener = parsed.items.find((i) => i.id === event.ref && i.type.endsWith('EventListener'));
      if (listener !== undefined) next = occur(runtime, listener.id);

      await deps.state.save(taskId, model, parsed, next);
      // 前提前推:事件写数据 → 任务视图变化 → 前提求值 → 新项 Enabled
      return this.runTurn(taskId);
    },

    /** 能算的不问 LLM:输入齐备的决策表确定性求值,命中行留痕 */
    async decide(taskId, decision) {
      const { model } = await loaded(taskId);
      const scope = await deps.data.view(taskId);
      const order = evaluationOrder(model.dmn, decision);
      const enriched: Record<string, unknown> = { ...scope };
      let last = undefined as ReturnType<typeof evaluateTable> | undefined;

      for (const step of order) {
        const table = model.dmn.tables.find((t) => t.id === step);
        if (table === undefined) continue;
        const result = evaluateTable(table, enriched, deps.sfeel.expression, deps.sfeel.unaryTest);
        last = result;
        if (result.kind !== 'decided') break;
        Object.assign(enriched, result.trace.outputs);
        await deps.memory.append({
          taskId,
          kind: 'evaluation',
          title: `DMN 求值:${table.label} → 命中 ${result.trace.hitRules.join('、')}`,
          detail: { inputs: result.trace.inputs, outputs: result.trace.outputs, table: table.id },
        });
      }

      return last ?? { kind: 'no-match', inputs: {} };
    },

    /** 驳回:相关计划项以新实例重新入场(repetitionRule),记为纠正信号 */
    async reenter(taskId, itemId) {
      const { model, parsed, runtime } = await loaded(taskId);
      const next = reenterItem(runtime, itemId);
      await deps.state.save(taskId, model, parsed, next);
      await deps.memory.append({
        taskId,
        kind: 'engine-transition',
        title: `驳回重入:${itemId}(新实例)`,
      });
      return next;
    },
  };
}