import type { EffortLevel } from "./effort.ts";

export type HarnessEventKind =
  | "session.start"
  | "session.end"
  | "prompt.submit"
  | "tool.before"
  | "tool.after"
  | "tool.failure"
  | "shell.before"
  | "shell.after"
  | "mcp.before"
  | "mcp.after"
  | "read.before"
  | "edit.after"
  | "subagent.start"
  | "subagent.stop"
  | "stop"
  | "compact.before"
  | "response.after"
  | "thought.after";

export const HARNESS_EVENT_KINDS: readonly HarnessEventKind[] = [
  "session.start",
  "session.end",
  "prompt.submit",
  "tool.before",
  "tool.after",
  "tool.failure",
  "shell.before",
  "shell.after",
  "mcp.before",
  "mcp.after",
  "read.before",
  "edit.after",
  "subagent.start",
  "subagent.stop",
  "stop",
  "compact.before",
  "response.after",
  "thought.after",
];

export type HarnessUsage = {
  inputTokens?: number;
  outputTokens?: number;
  cachedInputTokens?: number;
};

export type HarnessEvent = {
  provider: string;
  event: HarnessEventKind;
  sessionKey: string;
  projectDir: string;
  /**
   * The host's own report of the actual working directory for this event — the worktree root after
   * the agent enters one, or the directory after a `cd` ([/decisions/ad-114.md](/decisions/ad-114.md)).
   * Absent when the host does not report a per-event working directory. Distinct from `projectDir`,
   * which anchors state/config and deliberately does not move into a worktree.
   */
  cwd?: string;
  // hazard: the `spawn*` pair describes the child of a spawn; the unprefixed fields describe the
  // running agent. Conflating them clobbers sticky parent state.
  model?: string;
  spawnModel?: string;
  effort?: EffortLevel;
  text?: string;
  toolName?: string;
  toolInput?: Record<string, unknown>;
  command?: string;
  filePath?: string;
  subagentType?: string;
  spawnSubagentType?: string;
  /** What the host calls a spawn — its name, which the spawning agent chooses. Never a type to match against. */
  spawnAgentLabel?: string;
  status?: "completed" | "aborted" | "error";
  loopCount?: number;
  /** Provider's own permission posture, when it exposes one. Absent means unknown, not permissive. */
  permissionMode?: string;
  contextUsagePercent?: number;
  transcriptPath?: string;
  usage?: HarnessUsage;
  /**
   * What the tool returned, when the host delivers it.
   *
   * why: measured across 69,034 real records before this existed. Every host that delivers it uses its own field
   * name and its own type — three names and two types across the two adapters — so the translation belongs to
   * each adapter and this is the one shape core reads ([/decisions/ad-077.md](/decisions/ad-077.md)).
   *
   * invariant: absent is absent. Two of the after-events measured carry nothing on 21,167 records, so a reader
   * that assumed presence would be blind on the majority of one host's traffic.
   */
  toolOutput?: string;
  /**
   * The new text an Edit/Write-shaped tool call is about to introduce, when this project has confirmed the
   * shape: full file content for a whole-file write, or the replacement fragment for a targeted edit. Absent
   * for every other tool_name — the signal a downstream check uses to abstain rather than guess a field name
   * (same per-adapter-translation pattern as `toolOutput` above, [/decisions/ad-077.md](/decisions/ad-077.md)).
   */
  proposedContent?: string;
  /** Targeted-edit shape only: the text being replaced, needed to locate the edit's real position in the on-disk file. */
  proposedOldContent?: string;
  /** Adapter-only escape hatch — core must not read this. */
  raw: Record<string, unknown>;
};