export type MachineKind = "local" | "remote";
export type MachineStatus = "unknown" | "online" | "offline" | "error";

export const PI_WEB_CAPABILITIES = {
  sessionsDeleteArchived: "sessions.deleteArchived",
  sessionsBulkMutations: "sessions.bulkMutations",
  sessionsCleanup: "sessions.cleanup",
  sessionsReload: "sessions.reload",
  sessionsClearQueue: "sessions.clearQueue",
  sessionsPersistedState: "sessions.persistedState",
  sessionsNotifications: "sessions.notifications",
  sessionsUnread: "sessions.unread",
  sessionsAskUser: "sessions.askUser",
  promptAttachments: "prompt.attachments",
  workspaceFileSuggestions: "workspace.fileSuggestions",
  piPackagesManage: "piPackages.manage",
  selectedMachineSettings: "settings.selectedMachine",
  agentProfileConfig: "settings.agentProfile",
} as const;

export type PiWebCapability = typeof PI_WEB_CAPABILITIES[keyof typeof PI_WEB_CAPABILITIES];

export interface Machine {
  id: string;
  name: string;
  kind: MachineKind;
  baseUrl?: string;
  createdAt: string;
  updatedAt: string;
  status?: MachineStatus;
  statusMessage?: string;
}

export interface MachineHealth {
  machineId: string;
  ok: boolean;
  checkedAt: string;
  status?: MachineStatus;
  web?: PiWebComponentStatus;
  sessiond?: PiWebComponentStatus;
  error?: string;
}

export interface MachineRuntime {
  machineId: string;
  ok: boolean;
  checkedAt: string;
  packageName?: string;
  generatedAt?: string;
  components?: PiWebRuntimeResponse["components"];
  capabilities?: PiWebCapability[];
  error?: string;
}

export type PiWebShortcutConfig = Record<string, string | null>;
export type PiWebPluginSettings = Record<string, unknown>;
export type PiWebPluginConfigMap = Record<string, PiWebPluginConfig>;

export interface PiWebPluginConfig {
  enabled?: boolean;
  settings?: PiWebPluginSettings;
  [key: string]: unknown;
}

export interface PiWebPathAccessConfig {
  allowedPaths?: string[];
}

export interface PiWebUploadsConfig {
  defaultFolder?: string;
}

export interface PiWebAgentConfig {
  /** Pi-compatible companion CLI used for diagnostics and safe package-managed updates. */
  command?: string;
  /** Pi-compatible profile directory containing auth.json, models.json, settings.json, and sessions/. */
  dir?: string;
}

export interface PiWebConfigValues {
  host?: string;
  port?: number;
  allowedHosts?: string[] | true;
  shortcuts?: PiWebShortcutConfig;
  plugins?: PiWebPluginConfigMap;
  /** External filesystem roots PI WEB may expose outside a workspace. */
  pathAccess?: PiWebPathAccessConfig;
  /** Workspace-relative defaults for manual file uploads. */
  uploads?: PiWebUploadsConfig;
  /** Maximum accepted HTTP request body size in bytes (uploads/attachments). */
  maxUploadBytes?: number;
  /** When true, LLMs can start new sessions via the spawn_session tool. */
  spawnSessions?: boolean;
  /**
   * Beta: when true, LLMs can start tracked child sessions via the
   * spawn_subsession / list_subsessions / check_subsession / read_subsession
   * tools. Off by default
   * while the capability stabilizes. Requires spawnSessions to be enabled.
   */
  subsessions?: boolean;
  /**
   * When true, LLMs can post a question set to the browser via the ask_user
   * tool. On by default; set to `false` to remove the tool from the runtime.
   */
  askUser?: boolean;
  /** Desired Pi-compatible agent profile and companion CLI (Pi by default). */
  agent?: PiWebAgentConfig;
}

export type PiWebPluginScope = "bundled" | "local" | "user" | "project";

export interface PiWebPluginInfo {
  id: string;
  module: string;
  source: string;
  scope: PiWebPluginScope;
  machineSpecific: boolean;
  enabled: boolean;
}

export interface PiWebPluginsResponse {
  plugins: PiWebPluginInfo[];
}

export type PiPackageScope = "user" | "project";

export interface PiPackageInfo {
  source: string;
  scope: PiPackageScope;
  filtered: boolean;
  installedPath?: string;
}

export interface PiPackagesResponse {
  packages: PiPackageInfo[];
}

export interface PiPackageInstallRequest {
  source: string;
}

export interface PiPackageRemoveRequest {
  source: string;
  /** Optional known scope from a listed package; not an install-location picker. */
  scope?: PiPackageScope;
}

export interface PiPackageUpdateRequest {
  /** Omit to update all configured Pi packages. */
  source?: string;
}

export type PiPackageMutationAction = "install" | "remove" | "update";

export interface PiPackageMutationResponse extends PiPackagesResponse {
  action: PiPackageMutationAction;
  source?: string;
  scope?: PiPackageScope;
  removed?: boolean;
}

export type PiWebAgentDirEnvSource = "pi-web" | "pi-compatibility";

export interface PiWebConfigEnvOverrides {
  host: boolean;
  port: boolean;
  allowedHosts: boolean;
  spawnSessions: boolean;
  subsessions: boolean;
  askUser: boolean;
  agentCommand: boolean;
  agentDir: boolean;
  /** The configured directory environment source, even when Pi compatibility is inactive for the desired command. */
  agentDirSource?: PiWebAgentDirEnvSource;
  agentSessionDir: boolean;
}

export interface PiWebConfigResponse {
  path: string;
  exists: boolean;
  config: PiWebConfigValues;
  effectiveConfig: PiWebConfigValues;
  envOverrides: PiWebConfigEnvOverrides;
}

export interface Project {
  id: string;
  name: string;
  path: string;
  createdAt: string;
}

export interface WorkspaceEffectiveConfig {
  uploads?: PiWebUploadsConfig;
}

export interface Workspace {
  id: string;
  projectId: string;
  path: string;
  label: string;
  branch?: string;
  isMain: boolean;
  isGitRepo: boolean;
  isGitWorktree: boolean;
  /** Workspace-effective project/global settings needed by workspace UI features. */
  effectiveConfig?: WorkspaceEffectiveConfig;
}

export interface SessionRef {
  id: string;
  cwd: string;
}

export const SESSION_UNREAD_LIMIT = 1_000;
export const SESSION_UNREAD_SESSION_ID_MAX_LENGTH = 512;
export const SESSION_UNREAD_CWD_MAX_LENGTH = 32 * 1024;
export const SESSION_UNREAD_CATALOG_ID_MAX_LENGTH = 512;
export const SESSION_UNREAD_COMPLETED_AT_MAX_LENGTH = 64;

export interface SessionUnreadSummary {
  sessionId: string;
  cwd: string;
  /** Monotonic within a catalog and never greater than its containing revision. */
  completionOrder: number;
  completedAt: string;
}

export interface SessionUnreadCatalogSnapshot {
  /** Stable for one persisted catalog epoch; changes when unread state is reset. */
  catalogId: string;
  /** Monotonic catalog mutation revision; at least every contained completion order. */
  catalogRevision: number;
  /** Bounded by `SESSION_UNREAD_LIMIT` and ordered newest completion first. */
  sessions: SessionUnreadSummary[];
}

export interface SessionUnreadAcknowledgeRequest {
  cwd: string;
  /** The catalog epoch in which `throughCompletionOrder` was observed. */
  catalogId: string;
  throughCompletionOrder: number;
}

/** Authoritative delta for one session in the daemon-owned unread catalog. */
export interface SessionUnreadEvent {
  type: "sessions.unread";
  catalogId: string;
  /** At least `unread.completionOrder` when carrying an unread summary. */
  catalogRevision: number;
  sessionId: string;
  cwd: string;
  unread: SessionUnreadSummary | null;
}

export const SESSION_NOTIFICATION_LIMIT = 100;
export const SESSION_NOTIFICATION_MESSAGE_BYTES = 8 * 1024;

export type SessionNotificationSeverity = "info" | "warning" | "error";

export interface SessionNotification {
  id: string;
  message: string;
  truncated: boolean;
  severity: SessionNotificationSeverity;
  receivedAt: string;
  order: number;
}

export interface SessionNotificationSummary {
  sessionId: string;
  cwd: string;
  inboxRevision: number;
  retainedCount: number;
  discardedCount: number;
  highestSeverity?: SessionNotificationSeverity;
}

export interface SessionNotificationDismissThrough {
  order: number;
  overflowWatermark: number;
}

export interface SessionNotificationInboxSnapshot {
  daemonInstanceId: string;
  catalogRevision: number;
  summary: SessionNotificationSummary;
  notifications: SessionNotification[];
  dismissThrough: SessionNotificationDismissThrough;
}

export interface SessionNotificationCatalogSnapshot {
  daemonInstanceId: string;
  catalogRevision: number;
  sessions: SessionNotificationSummary[];
}

export interface SessionNotificationDismissRequest {
  cwd: string;
  daemonInstanceId: string;
  notificationId: string;
}

export interface SessionNotificationDismissAllRequest {
  cwd: string;
  daemonInstanceId: string;
  throughOrder: number;
  throughOverflowWatermark: number;
}

export type SessionNotificationClearReason =
  | "runtime-close"
  | "archive"
  | "delete"
  | "restore"
  | "archive-reconcile"
  | "replacement"
  | "initialization-failed"
  | "service-dispose";

export type SessionNotificationInboxDelta =
  | { kind: "added"; notification: SessionNotification; evictedNotificationId?: string }
  | { kind: "dismissed"; notificationIds: string[] }
  | { kind: "cleared"; reason: SessionNotificationClearReason }
  | { kind: "resync" };

export interface SessionNotificationInboxEvent {
  type: "notifications.inbox";
  daemonInstanceId: string;
  catalogRevision: number;
  summary: SessionNotificationSummary;
  dismissThrough: SessionNotificationDismissThrough;
  delta: SessionNotificationInboxDelta;
}

export interface SessionNotificationSummaryEvent {
  type: "notifications.summary";
  daemonInstanceId: string;
  catalogRevision: number;
  summary: SessionNotificationSummary;
}

export interface SessionInfo extends SessionRef {
  path: string;
  /** True when the server has verified a backing session file exists; false when known transient. */
  persisted?: boolean;
  name?: string;
  created: string;
  modified: string;
  messageCount: number;
  firstMessage: string;
  parentSessionPath?: string;
  /**
   * Working directory of the parent session, read from the parent session file
   * header. Only populated when the parent is outside this listing's cwd, so a
   * child whose parent lives in another worktree can point at it instead of
   * only reporting that the parent is unavailable here.
   */
  parentSessionCwd?: string;
  /** Session id of an out-of-cwd parent, so the browser can select it after switching workspace. */
  parentSessionId?: string;
  /**
   * Number of sessions in other workspaces of the same project that record this
   * session as their parent. Only set when non-zero, so a parent can show that
   * it has children which are not nested beneath it in this workspace.
   */
  childSessionsElsewhere?: number;
  archived?: boolean;
  archivedAt?: string;
}

export interface ArchiveSessionsResponse {
  archived: true;
  sessionIds?: string[];
  archivedCount?: number;
  skippedAlreadyArchivedCount?: number;
}

export interface SessionBulkMutationRef {
  id: string;
  cwd?: string;
}

export interface SessionBulkMutationRequest {
  sessions: SessionBulkMutationRef[];
}

export interface SessionBulkFailure {
  sessionId: string;
  error: string;
}

export interface SessionBulkArchiveResponse {
  archived: true;
  archivedSessionIds: string[];
  failures: SessionBulkFailure[];
  generatedAt: string;
}

export interface SessionBulkDeleteArchivedResponse {
  deleted: true;
  deletedSessionIds: string[];
  failures: SessionBulkFailure[];
  generatedAt: string;
}

export interface SessionCleanupRequest {
  /** Archive non-archived sessions whose modified time is older than this many days. Omit/null to disable. */
  archiveIdleDays?: number | null;
  /** Permanently delete archived sessions whose archivedAt time is older than this many days. Omit/null to disable. */
  deleteArchivedDays?: number | null;
  /** Stored cwd paths selected from a preview. Omit/null to include all discovered project/workspace paths. */
  projectCwds?: string[] | null;
}

export interface SessionCleanupThresholds {
  archiveIdleDays?: number;
  deleteArchivedDays?: number;
}

export interface SessionCleanupProjectSummary {
  cwd: string;
  archiveCount: number;
  deleteCount: number;
}

export interface SessionCleanupTotals {
  archiveCount: number;
  deleteCount: number;
}

export interface SessionCleanupPreviewResponse {
  generatedAt: string;
  thresholds: SessionCleanupThresholds;
  projects: SessionCleanupProjectSummary[];
  totals: SessionCleanupTotals;
  skippedBusySessionIds?: string[];
}

export interface SessionCleanupExecuteResponse extends SessionCleanupPreviewResponse {
  archivedSessionIds: string[];
  deletedSessionIds: string[];
}

export interface SessionActivity {
  sessionId: string;
  phase: "active" | "idle" | "error";
  label: string;
  detail?: string;
  at: string;
  /**
   * Set only on the startup window's own reports. A startup phase is genuinely
   * in progress, so it is published as `active` and rendered like any other
   * activity, but *starting* a session is not *working* in it: there is nothing
   * to stop, nothing that blocks reloading from disk, and no workspace-level
   * work to report. `isSessionActive()` reads this to keep the two apart.
   */
  startup?: boolean;
}

export interface QueuedSessionMessage {
  kind: "steer" | "followUp";
  text: string;
}

/**
 * `customType` of the follow-up custom message that carries a closed ask back to
 * the model and into the transcript. Its `details` are an {@link AskUserOutcome}.
 */
export const ASK_USER_ANSWERS_CUSTOM_TYPE = "pi-web.ask.answers";

/** Largest question set one `ask_user` call may post. */
export const ASK_USER_QUESTION_LIMIT = 20;
/** Largest option list one question may offer. */
export const ASK_USER_OPTION_LIMIT = 12;
/** Length bound for ids: the ask id, question ids, and option values. */
export const ASK_USER_ID_MAX_LENGTH = 128;
/** Length bound for model-authored prose: questions, details, and option labels. */
export const ASK_USER_TEXT_MAX_LENGTH = 1_000;
/** Length bound for the free text a user types as a custom answer. */
export const ASK_USER_OTHER_TEXT_MAX_LENGTH = 4_000;

/** One selectable option of an {@link AskUserQuestion}. */
export interface AskUserQuestionOption {
  /** Stable machine value reported back to the model. */
  value: string;
  /** Short human label rendered in the browser. */
  label: string;
  /** Optional clarifying line rendered under the label. */
  detail?: string;
}

/**
 * One question of an `ask_user` set. Questions are never required: the user may
 * submit while leaving any of them untouched, and unanswered questions are
 * reported to the model as such.
 */
export interface AskUserQuestion {
  /** Unique within the ask; used as the answer key. */
  id: string;
  /** The question itself, as one plain-text line. */
  question: string;
  /** Optional supporting context rendered under the question. */
  detail?: string;
  /** Offered options; may be empty when only free text makes sense. */
  options: AskUserQuestionOption[];
  /**
   * Compatibility marker for older clients. Canonical questions set this to
   * true because every question offers a custom free-text answer.
   */
  allowOther?: boolean;
  /** When true, several options may be selected at once. */
  multiple?: boolean;
}

/**
 * The open, unanswered question set of a session. Daemon-owned and reported in
 * {@link SessionStatus}, so a reconnecting or reloading browser rehydrates it
 * without depending on having seen the `ask.opened` event.
 */
export interface PendingAskUser {
  askId: string;
  askedAt: string;
  questions: AskUserQuestion[];
}

/** Why an ask stopped being the session's open ask. */
export type AskUserCloseReason = "submitted" | "superseded" | "cancelled";

/**
 * What the user replied to one question. Absent from a submission means the
 * question was left untouched; an empty `values` with no `otherText` means the
 * same thing.
 */
export interface AskUserAnswer {
  /** Matches an {@link AskUserQuestion.id} of the open ask. */
  id: string;
  /** Selected {@link AskUserQuestionOption.value} entries; several only when the question allows it. */
  values: string[];
  /** Free text typed as the question's custom answer. */
  otherText?: string;
}

/** One submit of the open ask: answers for some or all of its questions. */
export interface AskUserSubmission {
  answers: AskUserAnswer[];
}

/**
 * One question of a closed ask paired with what came back for it. Carries the
 * question itself so the record renders without the original ask still existing.
 */
export interface AskUserQuestionRecord {
  question: AskUserQuestion;
  /** True when at least one option was selected or custom text was given. */
  answered: boolean;
  values: string[];
  otherText?: string;
}

/**
 * The complete result of an ask, computed when it closes. Shared by the
 * model-facing follow-up message and the browser's read-only record, so both
 * report the same answered and unanswered questions.
 */
export interface AskUserOutcome {
  askId: string;
  reason: AskUserCloseReason;
  askedAt: string;
  closedAt: string;
  questions: AskUserQuestionRecord[];
  answeredCount: number;
  /** Ids of the questions left unanswered, in the order they were asked. */
  unansweredIds: string[];
  /** One line, for example `Answered 3 of 5; unanswered: q2, q5`. */
  summary: string;
}

/**
 * Result of the browser closing an ask by submitting or cancelling it.
 *
 * `"stale"` is an ordinary race rather than an error: the named ask was already
 * submitted, superseded by a newer one, or gone with its session runtime. The
 * browser drops its card and trusts `sessionStatus`, which is returned in both
 * cases so closing an ask needs no follow-up status request.
 */
export interface AskUserCloseResponse {
  result: "closed" | "stale";
  /** Present only when this call is the one that closed the ask. */
  outcome?: AskUserOutcome;
  sessionStatus: SessionStatus;
}

/**
 * Progress of the session startup window, where the daemon is still
 * constructing the agent session and no `PiAgentSession` exists yet, so
 * `activity.update` cannot be published for it.
 *
 * `startupToken` is the opaque label a create request supplied, echoed back so a
 * browser row still waiting for a session id recognises its own construction.
 * The daemon never interprets it and it never becomes the session id:
 * `activity.sessionId` always carries the real id, which is how an *open* of a
 * session the browser already knows is routed instead.
 *
 * `activity.phase === "idle"` means the startup window ended with nothing left
 * to report, so a browser that substituted its own text should restore it.
 */
export interface SessionStartupProgressEvent {
  type: "session.startup";
  startupToken?: string;
  activity: SessionActivity;
}

/**
 * A pi-native image attachment carried with a prompt. The wire format mirrors
 * pi's own `ImageContent` shape (`{ type: "image", data, mimeType }`) so these
 * attachments are compatible with native multimodal delivery after validation.
 */
export interface PromptImageAttachment {
  kind: "image";
  /** Supported image MIME type (image/png, image/jpeg, image/gif, or image/webp). */
  mimeType: string;
  /** Base64-encoded binary payload (no data: URL prefix). */
  data: string;
  /** Optional original filename, used for previews and folder-mode filenames. */
  name?: string;
}

/** A general file attachment that must be saved into the workspace before use. */
export interface PromptFileAttachment {
  kind: "file";
  /** Non-empty IANA MIME type (for example "application/pdf"). */
  mimeType: string;
  /** Base64-encoded binary payload (no data: URL prefix). Empty for zero-byte files. */
  data: string;
  /** Optional original filename, used for previews and folder-mode filenames. */
  name?: string;
}

export type PromptAttachment = PromptImageAttachment | PromptFileAttachment;

/**
 * How prompt attachments should be delivered to the session.
 * - "inline": send the binary to pi as native image content (multimodal input).
 * - "folder": save the file into the workspace and reference it from the prompt
 *   text so the agent reads it with its own tools.
 */
export type PromptAttachmentDelivery = "inline" | "folder";

export interface SavedPromptAttachment {
  /** Workspace-relative path the attachment was written to. */
  path: string;
  mimeType: string;
  size: number;
}

export interface SessionModel {
  provider?: string;
  id?: string;
  name?: string;
  contextWindow?: number;
  reasoning?: unknown;
}

// Domain type is owned by pi and re-exported from the shared thinking-levels
// module. Wire/data fields below intentionally use `string` so an unknown level
// from a newer pi runtime parses and renders gracefully instead of failing.
export type { ThinkingLevel } from "./thinkingLevels.js";

export type AuthType = "oauth" | "api_key";
export type AuthStatusSource = "stored" | "runtime" | "environment" | "fallback" | "models_json_key" | "models_json_command";

export interface AuthProviderStatus {
  configured: boolean;
  source?: AuthStatusSource;
  label?: string;
}

export interface AuthProviderOption {
  id: string;
  name: string;
  authType: AuthType;
  status: AuthProviderStatus;
  /** Additive hint: use the generic AuthInteraction transport instead of the legacy one-secret form. */
  loginFlow?: "interactive";
}

export interface AuthProvidersResponse {
  providers: AuthProviderOption[];
}

export interface OAuthFlowState {
  flowId: string;
  providerId: string;
  providerName: string;
  status: "running" | "complete" | "error" | "cancelled";
  auth?: {
    url: string;
    instructions?: string;
    deviceCode?: { userCode: string; intervalSeconds?: number; expiresInSeconds?: number };
  };
  prompt?: {
    requestId: string;
    message: string;
    placeholder?: string;
    allowEmpty?: boolean;
    /** Additive semantic detail; legacy peers continue to use `kind`. */
    promptType?: "text" | "secret" | "manual_code";
    kind: "prompt" | "manual";
  };
  select?: { requestId: string; message: string; options: CommandOption[] };
  progress: string[];
  info?: { message: string; links?: { url: string; label?: string }[] }[];
  error?: string;
}

export interface ModelSelectionResponse {
  models: SessionModel[];
}

export interface ThinkingLevelsResponse {
  levels: string[];
}

export type SessionWarningSeverity = "info" | "warning" | "error";

/**
 * A live, runtime-scoped warning surfaced to the browser (skill/resource
 * diagnostics, extension load errors, subscription-auth billing notice, etc.).
 *
 * Warnings are recomputed whenever the runtime is (re)built inside sessiond and
 * are not persisted chat messages. `source` is an optional short origin label
 * (e.g. `"skill"`, `"extension"`, `"anthropic"`); `path` carries a related file
 * path when the warning came from a resource diagnostic.
 *
 * `dismiss` is present only when the warning has a durable, first-class
 * off-switch in the underlying `pi` agent (not a UI-only hide). Its `id` is the
 * opaque token the server maps back to that suppression; the client renders a
 * dismiss control for any warning carrying it, without knowing what it means.
 */
export interface SessionWarning {
  severity: SessionWarningSeverity;
  message: string;
  source?: string;
  path?: string;
  dismiss?: { id: string };
}

export interface SessionStatus {
  sessionId: string;
  /** True when the server has verified a backing session file exists; false when known transient. */
  persisted?: boolean;
  model?: SessionModel;
  thinkingLevel?: string;
  isStreaming: boolean;
  isCompacting: boolean;
  isBashRunning: boolean;
  pendingMessageCount: number;
  queuedMessages: QueuedSessionMessage[];
  messageCount?: number;
  tokens: { input: number; output: number; cacheRead: number; cacheWrite: number; total: number };
  cost: number;
  contextUsage?: { tokens: number | null; contextWindow: number; percent: number | null };
  /**
   * Live, runtime-scoped warnings for this session (skill/resource diagnostics,
   * extension load errors, Anthropic subscription-auth billing notice, etc.).
   * Recomputed on each status read from the current runtime; absent/empty when
   * there are none. See {@link SessionWarning}.
   */
  warnings?: SessionWarning[];
  /**
   * The session's open `ask_user` question set, when one is waiting for the
   * user. Daemon-owned, so it survives browser reload and web/API restarts.
   */
  pendingAsk?: PendingAskUser;
}

export interface WorkspaceActivity {
  cwd: string;
  hasSessionActivity: boolean;
  hasTerminalActivity: boolean;
  updatedAt: string;
}

export interface WorkspaceActivityResponse {
  workspaces: WorkspaceActivity[];
  generatedAt: string;
}

export interface SlashCommand {
  name: string;
  description?: string;
  source: "extension" | "prompt" | "skill" | "builtin";
}

export interface FileSuggestion {
  path: string;
  kind: "tracked" | "untracked" | "other";
}

export interface FileTreeEntry {
  name: string;
  path: string;
  type: "file" | "directory" | "symlink";
  size?: number;
  modifiedAt?: string;
}

export interface FileTreeResponse {
  path: string;
  entries: FileTreeEntry[];
  scannedAt: string;
  truncated: boolean;
}

export type FileContentMediaType = "image";

export interface FileContentResponse {
  path: string;
  language?: string;
  mediaType?: FileContentMediaType;
  mimeType?: string;
  encoding: "utf8";
  size: number;
  modifiedAt: string;
  content: string;
  truncated: boolean;
  binary: boolean;
}

export interface WriteWorkspaceFileOptions {
  createDirs?: boolean;     // default: true — mkdir -p equivalent
  overwrite?: boolean;      // default: true — throw if false and file exists
}

export interface WriteWorkspaceFileResponse {
  path: string;
  size: number;
  modifiedAt: string;
  created: boolean;  // true if file was created, false if overwritten
}

export interface DeleteWorkspaceFileResponse {
  path: string;
  existed: boolean;  // true if file existed and was deleted, false if file did not exist
}

export interface MoveWorkspaceFileOptions {
  createDirs?: boolean;   // default: true — mkdir -p equivalent for target parent directory
  overwrite?: boolean;    // default: false — throw if target exists (safer default than writeFile)
}

export interface MoveWorkspaceFileResponse {
  fromPath: string;
  toPath: string;
  size: number;
  modifiedAt: string;
}

export type GitFileState = "unmodified" | "modified" | "added" | "deleted" | "renamed" | "copied" | "untracked" | "ignored" | "conflicted";

export interface GitStatusFile {
  path: string;
  oldPath?: string;
  index: GitFileState;
  workingTree: GitFileState;
  // Set only on a submodule commit-pointer entry (path equals the submodule's
  // superproject-relative path). Short SHAs of the recorded and current commit.
  submoduleFromCommit?: string;
  submoduleToCommit?: string;
}

export interface GitStatusResponse {
  isGitRepo: boolean;
  hash: string;
  branch?: string;
  upstream?: string;
  ahead?: number;
  behind?: number;
  files: GitStatusFile[];
  // Superproject-relative paths of submodules that carry a change. Files inside
  // a submodule appear in `files` under `<submodule>/<inner path>`; the client
  // uses this list to group and label them and to distinguish a submodule root
  // from an ordinary directory with the same name.
  submodules: string[];
}

export interface GitDiffResponse {
  path?: string;
  staged: boolean;
  hash: string;
  diff: string;
  truncated: boolean;
}

export interface TerminalInfo {
  id: string;
  cwd: string;
  name: string;
  createdAt: string;
  exited: boolean;
  exitCode?: number;
  commandRunId?: string;
}

export type TerminalCommandRunStatus = "queued" | "running" | "succeeded" | "failed";

export interface TerminalCommandRun {
  id: string;
  origin: string;
  projectId: string;
  workspaceId: string;
  terminalId: string;
  title: string;
  command: string;
  status: TerminalCommandRunStatus;
  exitCode?: number;
  createdAt: string;
  startedAt?: string;
  completedAt?: string;
  metadata: Record<string, string>;
}

export interface RunTerminalCommandInput {
  workspace: Workspace;
  title: string;
  command: string;
  metadata?: Record<string, string>;
  open?: boolean;
}

export interface TerminalCommandRunHandle {
  run: TerminalCommandRun;
  completed: Promise<TerminalCommandRun>;
}

export interface TerminalCommandRunFilter {
  projectId?: string;
  workspaceId?: string;
  terminalId?: string;
  statuses?: TerminalCommandRunStatus[];
  metadata?: Record<string, string>;
}

export type PiWebServiceComponent = "web" | "sessiond";
export type PiWebStatusSeverity = "info" | "warning" | "error";
export type PiWebInstallationKind = "pi-package" | "npm-global" | "local" | "docker" | "unknown";
export type PiWebDockerMode = "runtime" | "dev";

export interface PiWebInstallationInfo {
  kind: PiWebInstallationKind;
  path?: string;
  source?: string;
  scope?: "user" | "project";
  npmRoot?: string;
  dockerMode?: PiWebDockerMode;
}

export interface PiWebComponentStatus {
  component: PiWebServiceComponent;
  label: string;
  runtimeVersion?: string;
  installedVersion?: string;
  stale: boolean;
  available: boolean;
  installation?: PiWebInstallationInfo;
  error?: string;
}

/** Secret-free identity of the Pi-compatible CLI/state profile fixed for one sessiond lifetime. */
export interface ActiveAgentProfileDescriptor {
  readonly schemaVersion: 1;
  readonly revision: string;
  readonly command: string;
  readonly dir: string;
  readonly sessionDirEnvKeys: readonly string[];
}

export interface PiWebRuntimeComponent {
  component: PiWebServiceComponent;
  label: string;
  runtimeVersion?: string;
  available: boolean;
  capabilities: PiWebCapability[];
  /** Present only for a session daemon that supports active-profile reporting. */
  activeAgentProfile?: ActiveAgentProfileDescriptor;
  error?: string;
}

export interface PiWebReleaseStatus {
  packageName: string;
  latestVersion?: string;
  updateAvailable: boolean;
  checkedAt?: string;
  skipped?: boolean;
  error?: string;
}

export interface PiWebStatusMessage {
  id: string;
  severity: PiWebStatusSeverity;
  title: string;
  body: string;
  command?: string;
}

export interface PiWebVersionResponse {
  packageName: string;
  generatedAt: string;
  components: {
    web: PiWebComponentStatus;
    sessiond: PiWebComponentStatus;
  };
}

export interface PiWebRuntimeResponse {
  packageName: string;
  generatedAt: string;
  components: {
    web: PiWebRuntimeComponent;
    sessiond: PiWebRuntimeComponent;
  };
  capabilities: PiWebCapability[];
}

export interface PiWebStatusResponse extends PiWebVersionResponse {
  release: PiWebReleaseStatus;
  commands: {
    update?: string;
    restart?: string;
    restartWeb?: string;
    restartSessiond?: string;
    status?: string;
  };
  messages: PiWebStatusMessage[];
}

export type TerminalUiEvent =
  | { type: "terminal.created"; terminal: TerminalInfo }
  | { type: "terminal.exited"; terminal: TerminalInfo }
  | { type: "terminal.closed"; terminalId: string; cwd: string };

export interface WorkspaceActivityUiEvent {
  type: "workspace.activity";
  activity: WorkspaceActivity;
}

export interface CommandOption {
  value: string;
  label: string;
  description?: string;
}

export type SessionTreeNodeKind =
  | "user"
  | "assistant"
  | "tool-result"
  | "bash"
  | "custom-message"
  | "compaction"
  | "branch-summary"
  | "model-change"
  | "thinking-level-change"
  | "session-info"
  | "label"
  | "custom"
  | "other";

export interface SessionTreeNode {
  id: string;
  parentId: string | null;
  kind: SessionTreeNodeKind;
  summary: string;
  timestamp?: string;
  label?: string;
}

export interface SessionTreeSnapshot {
  /** Pre-order, parent-linked projection of all retained roots and descendants. */
  nodes: SessionTreeNode[];
  activeLeafId: string | null;
  /** Root-to-leaf IDs for explicit, non-color-only active-path rendering. */
  activePathIds: string[];
}

export const SESSION_TREE_CUSTOM_INSTRUCTIONS_MAX_LENGTH = 10_000;

export type SessionTreeSummaryChoice =
  | { mode: "none" }
  | { mode: "default" }
  | { mode: "custom"; instructions: string };

export interface SessionTreeNavigateRequest {
  targetId: string;
  /** Leaf shown when the navigator opened; null is valid for an empty/root position. */
  expectedLeafId: string | null;
  summary: SessionTreeSummaryChoice;
}

export type SessionTreeNavigateResult =
  | { cancelled: false; editorText?: string }
  | { cancelled: true; aborted?: boolean };

export interface MessagePage {
  messages: unknown[];
  start: number;
  total: number;
}

/**
 * Join-time snapshot of a session's in-flight assistant stream. `seq` is the
 * `SessionEventHub` watermark captured together with `partial` in a single tick,
 * so a joining client can seed `partial` and then apply only buffered live events
 * with `seq > snapshot.seq` (exactly-once). `partial` is a browser-projected
 * in-flight `AssistantMessage` (thinking signatures stripped), or `null` when the
 * session is not mid assistant-message stream.
 */
export interface SessionStreamSnapshot {
  seq: number;
  /** Browser-projected in-flight `AssistantMessage`, or `null` when idle. */
  partial: unknown;
}

export type CommandResult =
  | { type: "done"; message?: string; session?: SessionInfo; promptDraft?: string }
  | { type: "select"; requestId: string; title: string; options: CommandOption[] }
  | { type: "tree"; tree: SessionTreeSnapshot }
  | { type: "unsupported"; message: string };

/**
 * Transport-level per-session sequence stamp. `SessionEventHub.publish` assigns a
 * monotonic `seq` to every per-session event as it is serialized to the socket.
 * Clients use it as a watermark against the join-time stream snapshot so buffered
 * live events are applied exactly once. Existing consumers may ignore it.
 */
export type SessionUiEvent = SessionUiEventBody & { seq?: number };

type SessionUiEventBody =
  | { type: "message.append"; message: unknown }
  | { type: "assistant.delta"; text: string }
  | { type: "assistant.thinking.delta"; text: string }
  | { type: "tool.start"; toolName: string; toolCallId: string; summary: string; args?: unknown }
  | { type: "tool.update"; toolName: string; toolCallId: string; text: string; content?: unknown; details?: unknown }
  | { type: "tool.end"; toolName: string; toolCallId: string; text: string; isError: boolean; content?: unknown; details?: unknown }
  | { type: "shell.start"; command: string; excludeFromContext?: boolean }
  | { type: "shell.chunk"; chunk: string }
  | { type: "shell.end"; output?: string; exitCode?: number | null; cancelled?: boolean; truncated?: boolean; fullOutputPath?: string; isError?: boolean }
  | { type: "agent.start" }
  | { type: "agent.end" }
  | { type: "message.end"; message?: unknown }
  | { type: "status.update"; status: SessionStatus }
  | { type: "activity.update"; activity: SessionActivity }
  | { type: "command.output"; level: "info" | "success" | "error"; message: string; notificationId?: string }
  | SessionNotificationInboxEvent
  | { type: "session.error"; message: string }
  | { type: "ask.opened"; ask: PendingAskUser }
  | { type: "ask.closed"; askId: string; reason: AskUserCloseReason }
  | { type: "session.name"; sessionId: string; name?: string }
  | { type: "session.created"; session: SessionInfo }
  | { type: "pi.event"; eventType: string };

export type GlobalSessionEvent =
  | Extract<SessionUiEventBody, { type: "status.update" | "activity.update" | "session.name" | "session.created" }>
  | SessionNotificationSummaryEvent
  | SessionUnreadEvent
  | SessionStartupProgressEvent;
export type RealtimeEvent = GlobalSessionEvent | TerminalUiEvent | WorkspaceActivityUiEvent;