import { z } from "zod";
import type { AgentRunStatus } from "./agent.ts";
import { Id, JsonObject, NonNegInt, Timestamp } from "./common.ts";
import type { TypedEvent } from "./events.ts";

// Agent 运行事件(REQ §10.6):packages/agent 产生,server 先写 agent_run_event(带 seq)再推 SSE。
// 这里是唯一定义;agent 包的 onEvent 回调直接收 AgentRunEvent。

export const AgentRunEventType = z.enum([
  "run_started",
  "text_delta",
  "thinking_delta",
  "tool_call_start",
  "tool_call_end",
  "tool_call_rejected",
  "compaction",
  "run_completed",
  "run_failed",
  "subagent_spawned",
  "subagent_event",
  "subagent_completed",
]);
export type AgentRunEventType = z.infer<typeof AgentRunEventType>;

/** 一次运行累计用量(数值都齐全;写 agent_run.usage 时可直接用,是 AgentUsage 的子集形状) */
export const AgentUsageTotals = z.object({
  inputTokens: NonNegInt,
  outputTokens: NonNegInt,
  cacheReadTokens: NonNegInt,
  cacheWriteTokens: NonNegInt,
  totalTokens: NonNegInt,
  costUsd: z.number().nonnegative(),
});
export type AgentUsageTotals = z.infer<typeof AgentUsageTotals>;

export const AgentFailureReason = z.enum(["budget", "aborted", "error"]);
export type AgentFailureReason = z.infer<typeof AgentFailureReason>;
export const AgentBudgetKind = z.enum(["tool_calls", "duration", "tokens", "cost"]);
export type AgentBudgetKind = z.infer<typeof AgentBudgetKind>;

const RunStarted = z.object({ type: z.literal("run_started"), goal: z.string(), resumed: z.boolean() });
const TextDelta = z.object({ type: z.literal("text_delta"), delta: z.string() });
const ThinkingDelta = z.object({ type: z.literal("thinking_delta"), delta: z.string() });
const ToolCallStart = z.object({
  type: z.literal("tool_call_start"),
  toolCallId: z.string(),
  capabilityId: z.string(),
  /** 已脱敏、截断的输入摘要 */
  inputSummary: z.string(),
  /** 崩溃恢复后重放/补记的调用 */
  recovery: z.boolean(),
});
const ToolCallEnd = z.object({
  type: z.literal("tool_call_end"),
  toolCallId: z.string(),
  capabilityId: z.string(),
  isError: z.boolean(),
  /** 已脱敏、截断的输出摘要 */
  outputSummary: z.string(),
  recovery: z.boolean(),
});
const ToolCallRejected = z.object({
  type: z.literal("tool_call_rejected"),
  toolCallId: z.string(),
  toolName: z.string(),
  capabilityId: z.string().optional(),
  reason: z.string(),
});
const Compaction = z.object({
  type: z.literal("compaction"),
  phase: z.enum(["start", "end"]),
  reason: z.enum(["manual", "threshold", "overflow"]),
  status: z.enum(["completed", "declined", "aborted", "failed"]).optional(),
});
const RunCompleted = z.object({ type: z.literal("run_completed"), finalText: z.string(), usage: AgentUsageTotals });
const RunFailed = z.object({
  type: z.literal("run_failed"),
  reason: AgentFailureReason,
  message: z.string(),
  usage: AgentUsageTotals,
  budget: AgentBudgetKind.optional(),
});

// 子代理(agent.spawn):子会话的事件镜像进父会话事件流,由父会话的运行进程按父 seq 写入(单写者,seq 不冲突)。
const SubagentSpawned = z.object({
  type: z.literal("subagent_spawned"),
  childRunId: z.string(),
  goal: z.string(),
  mode: z.enum(["execute", "plan_only"]),
  depth: NonNegInt,
  capabilities: z.array(z.string()),
  /** 从父会话划拨给子会话的预算 */
  budget: z.record(z.string(), z.number()),
});
/** 子会话的一条事件(工具调用 / 开始 / 结束);childSeq 是子会话内的 seq,正文已脱敏截断 */
const SubagentEvent = z.object({
  type: z.literal("subagent_event"),
  childRunId: z.string(),
  childSeq: NonNegInt,
  childType: z.string(),
  capabilityId: z.string().optional(),
  summary: z.string(),
});
const SubagentCompleted = z.object({
  type: z.literal("subagent_completed"),
  childRunId: z.string(),
  status: z.string(),
  /** 子会话汇报摘要(业务核查结论 + 未经核查的模型文本),已脱敏截断 */
  summary: z.string(),
  usage: AgentUsageTotals,
  toolCalls: NonNegInt,
});

/** 事件主体(不含 runId/seq/at) */
export const AgentRunEventBody = z.discriminatedUnion("type", [
  RunStarted,
  TextDelta,
  ThinkingDelta,
  ToolCallStart,
  ToolCallEnd,
  ToolCallRejected,
  Compaction,
  RunCompleted,
  RunFailed,
  SubagentSpawned,
  SubagentEvent,
  SubagentCompleted,
]);
export type AgentRunEventBody = z.infer<typeof AgentRunEventBody>;

const EventMeta = {
  /** = agent_run.id */
  runId: z.string().min(1),
  /** 该 run 内从 0 起单调递增;续跑时从 agent_run.last_event_seq + 1 继续 */
  seq: NonNegInt,
  at: Timestamp,
};

/** 完整事件:主体 + runId/seq/at */
export const AgentRunEvent = z.discriminatedUnion("type", [
  RunStarted.extend(EventMeta),
  TextDelta.extend(EventMeta),
  ThinkingDelta.extend(EventMeta),
  ToolCallStart.extend(EventMeta),
  ToolCallEnd.extend(EventMeta),
  ToolCallRejected.extend(EventMeta),
  Compaction.extend(EventMeta),
  RunCompleted.extend(EventMeta),
  RunFailed.extend(EventMeta),
  SubagentSpawned.extend(EventMeta),
  SubagentEvent.extend(EventMeta),
  SubagentCompleted.extend(EventMeta),
]);
export type AgentRunEvent = AgentRunEventBody & { runId: string; seq: number; at: string };

/** agent_run_event 行:(run_id, seq) 唯一;payload = 事件主体去掉 type */
export const AgentRunEventRow = z.object({
  runId: Id,
  seq: NonNegInt,
  type: AgentRunEventType,
  at: Timestamp,
  payload: JsonObject,
});
export type AgentRunEventRow = z.infer<typeof AgentRunEventRow>;

export function agentRunEventToRow(e: AgentRunEvent): AgentRunEventRow {
  const { runId, seq, at, type, ...payload } = e;
  return { runId, seq, at, type, payload };
}

/** 行 → 事件;payload 不合法时抛错(表里只应有 agentRunEventToRow 写入的内容) */
export function agentRunEventFromRow(row: AgentRunEventRow): AgentRunEvent {
  return AgentRunEvent.parse({ ...row.payload, type: row.type, runId: row.runId, seq: row.seq, at: row.at });
}

/** 工具调用事件 → SSE agent.tool_call 的 phase */
export function toolCallPhase(e: AgentRunEventBody): "started" | "succeeded" | "failed" | "denied" | null {
  switch (e.type) {
    case "tool_call_start":
      return "started";
    case "tool_call_end":
      return e.isError ? "failed" : "succeeded";
    case "tool_call_rejected":
      return "denied";
    default:
      return null;
  }
}

/** run_completed / run_failed / run_started → agent_run.status */
export function agentRunStatusOf(e: AgentRunEventBody): AgentRunStatus | null {
  switch (e.type) {
    case "run_started":
      return "running";
    case "run_completed":
      return "succeeded";
    case "run_failed":
      return e.reason === "budget" ? "budget_exceeded" : e.reason === "aborted" ? "cancelled" : "failed";
    default:
      return null;
  }
}

/**
 * Agent 运行事件 → 全局 SSE 事件(agent.run_status / agent.text_delta / agent.tool_call)。
 * thinking_delta 与 compaction 不上全局总线(只在 run 详情里按 agent_run_event 回放),返回 null。
 */
export function agentRunEventToBusEvent(e: AgentRunEvent): TypedEvent | null {
  const phase = toolCallPhase(e);
  if (phase) {
    let capabilityId = "";
    let summary = "";
    if (e.type === "tool_call_start") [capabilityId, summary] = [e.capabilityId, e.inputSummary];
    else if (e.type === "tool_call_end") [capabilityId, summary] = [e.capabilityId, e.outputSummary];
    else if (e.type === "tool_call_rejected") [capabilityId, summary] = [e.capabilityId ?? e.toolName, e.reason];
    return { type: "agent.tool_call", payload: { runId: e.runId, runSeq: e.seq, capabilityId, phase, summary } };
  }
  // 子会话事件:借 agent.tool_call(能力 agent.spawn)提示父会话页"有新事件",页面按 seq 补读
  if (e.type === "subagent_spawned" || e.type === "subagent_event" || e.type === "subagent_completed") {
    const phase =
      e.type === "subagent_completed" ? (e.status === "succeeded" ? "succeeded" : "failed") : ("started" as const);
    const summary =
      e.type === "subagent_spawned"
        ? `派生子会话 ${e.childRunId}:${e.goal}`
        : e.type === "subagent_event"
          ? `子会话 ${e.childRunId}:${e.childType} ${e.capabilityId ?? ""} ${e.summary}`.trim()
          : `子会话 ${e.childRunId} ${e.status}:${e.summary}`;
    return {
      type: "agent.tool_call",
      payload: { runId: e.runId, runSeq: e.seq, capabilityId: "agent.spawn", phase, summary: summary.slice(0, 600) },
    };
  }
  if (e.type === "text_delta") {
    return { type: "agent.text_delta", payload: { runId: e.runId, runSeq: e.seq, delta: e.delta } };
  }
  const status = agentRunStatusOf(e);
  if (status) {
    const summary = e.type === "run_completed" ? e.finalText : e.type === "run_failed" ? e.message : null;
    return { type: "agent.run_status", payload: { runId: e.runId, status, summary } };
  }
  return null;
}