import { sqliteTable, text, integer, index, uniqueIndex } from "drizzle-orm/sqlite-core";
import { agents } from "./agent";
import { agentSessions } from "./agent";

/**
 * A2A Task ↔ Session 映射表
 *
 * 记录 A2A task ID 与内部 agentSession ID 的对应关系，
 * 以及调用链信息（caller / callee agent）、task 状态。
 *
 * 设计说明：
 * - 不改动现有 agentSessions schema，通过映射表关联
 * - taskId 为 A2A 协议层生成的 UUID，对调用方暴露
 * - sessionId 为内部 session ID，不直接暴露给 A2A 调用方
 */
export const a2aTaskSessions = sqliteTable(
  "a2a_task_sessions",
  {
    id: integer("id").primaryKey({ autoIncrement: true }),
    taskId: text("task_id", { length: 64 }).notNull().unique(),
    sessionId: text("session_id")
      .notNull()
      .references(() => agentSessions.id, { onDelete: "cascade" }),
    callerAgentId: integer("caller_agent_id").references(() => agents.id, { onDelete: "set null" }),
    calleeAgentId: integer("callee_agent_id")
      .notNull()
      .references(() => agents.id, { onDelete: "cascade" }),
    state: text("state", { length: 20 }).notNull().default("submitted"),
    callerContext: text("caller_context"),
    createdAt: integer("created_at", { mode: "timestamp_ms" }).defaultNow().notNull(),
    updatedAt: integer("updated_at", { mode: "timestamp_ms" })
      .defaultNow()
      .$onUpdate(() => new Date())
      .notNull(),
    completedAt: integer("completed_at", { mode: "timestamp_ms" }),
  },
  (table) => [
    uniqueIndex("a2a_task_sessions_task_id_uniq").on(table.taskId),
    index("a2a_task_sessions_session_idx").on(table.sessionId),
    index("a2a_task_sessions_callee_idx").on(table.calleeAgentId),
    index("a2a_task_sessions_state_idx").on(table.state),
  ],
);

export type A2aTaskSessionRow = typeof a2aTaskSessions.$inferSelect;