import {
  pgTable,
  uuid,
  varchar,
  text,
  integer,
  jsonb,
  timestamp,
  index,
} from "drizzle-orm/pg-core";

import { workspaces } from "./workspaces";
import { users } from "./users";
import { markdownBacklogItems } from "./markdown_backlog";

/**
 * One row per agent session against a backlog item. The MCP tools
 * (`claim_task`, `complete_task`, …) will be the write path in the next
 * epic; this table is read-side + storage only at this stage. Rows can
 * be inserted manually for development.
 *
 * Conventions captured here so future maintainers don't drift:
 *
 *   - `outcome` is constrained at the application layer to one of
 *     {succeeded, failed, cancelled, stalled}. The column is nullable
 *     because in-flight runs (no `finished_at`) carry NULL outcomes —
 *     surfaced in the UI as the synthetic "open" bucket.
 *
 *   - `actorUserId` is null for anonymous / dev sessions where no user
 *     is attached. The settings UI shows "—" for null actors.
 *
 *   - Token totals follow the Symphony model: a single absolute
 *     `tokens_total` recorded at close-out, not incremental deltas.
 *     `tokens_input` / `tokens_output` are optional breakdowns.
 *
 *   - `metadata` is JSONB but should stay small (roughly < 1 KB).
 *     Don't dump full transcripts here — that's what an external
 *     object store is for.
 *
 *   - Indexes are tuned for the two read paths the UI exercises:
 *     `(workspace_id, started_at DESC)` for the recent-runs settings
 *     view and `(backlog_item_id, started_at DESC)` for per-task
 *     history on the task detail panel (deferred to a follow-up task
 *     to avoid stepping on the parent's concurrent work).
 */
export const agentRuns = pgTable(
  "agent_runs",
  {
    id: uuid("id").primaryKey().defaultRandom(),
    workspaceId: uuid("workspace_id")
      .notNull()
      .references(() => workspaces.id, { onDelete: "cascade" }),
    backlogItemId: uuid("backlog_item_id")
      .notNull()
      .references(() => markdownBacklogItems.id, { onDelete: "cascade" }),
    actorUserId: uuid("actor_user_id").references(() => users.id, {
      onDelete: "set null",
    }),
    startedAt: timestamp("started_at", { withTimezone: true })
      .defaultNow()
      .notNull(),
    finishedAt: timestamp("finished_at", { withTimezone: true }),
    outcome: varchar("outcome", { length: 20 }),
    error: text("error"),
    tokensInput: integer("tokens_input"),
    tokensOutput: integer("tokens_output"),
    tokensTotal: integer("tokens_total"),
    notes: text("notes"),
    metadata: jsonb("metadata").$type<Record<string, unknown> | null>(),
  },
  (table) => ({
    workspaceStartedIdx: index("agent_runs_workspace_id_started_at_idx").on(
      table.workspaceId,
      table.startedAt.desc(),
    ),
    backlogStartedIdx: index("agent_runs_backlog_item_id_started_at_idx").on(
      table.backlogItemId,
      table.startedAt.desc(),
    ),
  }),
);