export const PROTOCOL_SCHEMA = 1 as const;
export const CONTEXT_ID = "linuxcnc-2.10.0-pre0-wasm-m1-py-c1" as const;

export type MessageKind =
  | "HELLO" | "CAPABILITIES" | "SESSION_ATTACH" | "SESSION_READY"
  | "LOAD_WORKSPACE" | "COMMAND_RESULT" | "STATE_SNAPSHOT" | "EVENT"
  | "ALARM" | "RECOVERY_STATUS" | "ERROR";

export type MessageEnvelope<TPayload = unknown> = {
  schema_version: typeof PROTOCOL_SCHEMA;
  kind: MessageKind | string;
  context_id: string;
  session_id: string;
  seq: number;
  operation_id?: string;
  simulation_tick?: number;
  payload: TPayload;
};

export type MotionSnapshot = {
  axes?: number[];
  joints?: number[];
  velocity?: number[];
  homed?: boolean | boolean[];
  homed_axes?: boolean[];
  limits?: number | Record<string, boolean>;
  on_any_limit?: boolean;
  fault?: string | null;
  velocity_limit?: number;
  velocity_scale?: number;
  jog_scale?: number;
  jog_velocity_linear?: number;
  jog_velocity_angular?: number;
  spindle_override?: number;
};

export type TrajectorySnapshot = {
  queue?: Array<{ id?: number; source_line?: number | null; start?: Record<string, number>; end?: Record<string, number> }>;
  active?: { id?: number; source_line?: number | null; start?: Record<string, number>; end?: Record<string, number> } | null;
  queue_depth?: number;
};

export type SimSnapshotV1 = {
  schema?: string;
  snapshot_id?: string;
  base_snapshot_id?: string;
  full?: boolean;
  simulation_tick: number;
  state_hash: string;
  task?: { state: string; mode: string; interp_state?: string; current_line?: number | null };
  program?: Record<string, unknown> | null;
  motion?: MotionSnapshot;
  wasm_motion?: Record<string, unknown>;
  authoritative?: { state_hash?: string; planner?: TrajectorySnapshot; kinematics?: Record<string, unknown> };
  coordinates?: { machine?: number[]; relative?: number[]; g5x?: number; g92?: number[]; tool_offset?: number[] };
  spindle?: Array<{ enabled?: boolean; direction?: number; commanded?: number; actual?: number; at_speed?: boolean }>;
  io?: { coolant?: number; lube?: boolean; digital?: number[]; analog?: number[]; probe?: boolean };
  tool?: { current?: number; prepared?: number; pocket?: number; change_state?: string };
  overrides?: { feed?: number; rapid?: number; spindle?: number[]; adaptive?: number; feed_hold?: boolean };
  hal?: { graph_revision?: number; changed_values?: ArrayBuffer };
  alarms?: Array<{ id?: string; severity?: string; code?: string; acknowledged?: boolean }>;
  recovery?: { status?: string; last_verified_seq?: number; checkpoint_tick?: number };
  panel_snapshot?: PanelSnapshotV1;
  configuration?: Record<string, unknown> | null;
  visual?: PanelSnapshotV1["visual"];
  motion_sample?: { tick?: number; pose?: Record<string, number>; joints?: number[]; active_segment_id?: number; active_progress?: number };
  snapshot_mode?: "full" | "motion_delta";
  kinematics?: XyzacKinematicsSnapshot;
  xyzac?: XyzacCapabilitySnapshot;
  gates?: Record<string, { action: string; enabled: boolean; reason: string }>;
  motion_authority?: string;
  task_authority?: string;
};

export type XyzacKinematicsSnapshot = {
  schema: "wasm-xyzac-kinematics.v1";
  status: "verified" | "error" | "blocked";
  active_type: 0 | 1 | 2;
  native_type: string;
  coordinates: "XYZAC";
  joint_count: 5;
  linear_units: "mm";
  angular_units: "deg";
  pose: Record<"x" | "y" | "z" | "a" | "b" | "c" | "u" | "v" | "w", number>;
  joints: [number, number, number, number, number];
  offsets: { x_rot_point: number; y_offset: number; z_offset: number; tool_offset: number };
  generation: number;
  switch_count: number;
  state_hash: string;
  wasm_state_hash: string;
};

export type XyzacCapabilitySnapshot = {
  coordinates: "XYZAC";
  joint_count: 5;
  active_type: 0 | 1 | 2;
  hal_pin_vars: boolean;
  switchkins_net: boolean;
  finite_offsets: boolean;
  userk_capability: boolean;
};

export type PanelSnapshotV1 = {
  schema: "axis-panel-snapshot.v1";
  context_id: string;
  session_id: string;
  simulation_tick: number;
  state_hash: string;
  task: Record<string, unknown>;
  program: Record<string, unknown> | null;
  motion: Record<string, unknown>;
  coordinates?: { machine?: number[]; relative?: number[]; commanded?: number[] };
  overrides?: { feed?: number; spindle?: number[] };
  wasm_motion: Record<string, unknown>;
  home_limit: Record<string, unknown>;
  hal: Record<string, unknown>;
  devices: Record<string, unknown>;
  device_io: Record<string, unknown>;
  configuration: Record<string, unknown> | null;
  axis_state: AxisStateView;
  gates: Record<string, { action: string; enabled: boolean; reason: string }>;
  visual: {
    schema: "axis-visual.v1";
    pose: Record<string, number>;
    joints: number[];
    toolpath?: Array<Record<string, unknown>>;
    active_segment_id?: number | null;
    active_progress?: number;
    motion_trace?: Array<{ tick: number; pose: Record<string, number>; joints: number[]; active_segment_id: number; active_progress: number }>;
    source: "wasm_canonical_motion";
  };
  authoritative: Record<string, unknown>;
  motion_authority: string;
  task_authority: string;
  kinematics?: XyzacKinematicsSnapshot;
  xyzac?: XyzacCapabilitySnapshot;
  io?: Record<string, unknown>;
};

export type Capabilities = {
  context_id?: string;
  abi?: Record<string, unknown>;
  snapshot?: Record<string, unknown>;
  commands?: string[];
  streams?: string[];
  limits?: Record<string, number>;
  exclusions?: string[];
};

export type AxisStateView = {
  state: "ESTOP" | "ESTOP_RESET" | "OFF" | "ON" | "HOME" | "IDLE" | "RUNNING" | "PAUSED";
  machine_state: "ESTOP" | "ESTOP_RESET" | "OFF" | "ON";
  operation_state: "HOME" | "IDLE" | "RUNNING" | "PAUSED";
  source_task_state: string;
  source_interp_state: string;
  source_mode: "MANUAL" | "MDI" | "AUTO";
};

export function isEnvelope(value: unknown): value is MessageEnvelope {
  if (!value || typeof value !== "object") return false;
  const candidate = value as Partial<MessageEnvelope>;
  return candidate.schema_version === PROTOCOL_SCHEMA
    && typeof candidate.kind === "string"
    && typeof candidate.context_id === "string"
    && typeof candidate.session_id === "string"
    && Number.isSafeInteger(candidate.seq)
    && "payload" in candidate;
}