/* Declarations for lib/blocks.js — the module itself ships unchanged. */

export interface WordEntry {
  ko: string;
  gloss: string;
  note: string;
}

/** What parse() stamps onto whichever task it returns. */
interface TaskMeta {
  /** How many earlier ::task blocks in the message were withdrawn. The
      LAST block wins; a non-zero count means the tutor retracted a draft. */
  retracted?: number;
  /** The block's raw rows, for the gate to read — see gate.js taskMaterial(). */
  rows?: string[];
}

export interface TranslateTask extends TaskMeta {
  type: "translate";
  items: { q: string }[];
}
/** English prompt; the student WRITES the 한글. The one type that proves
    recall rather than recognition, and the one that needs letterCheck(). */
export interface RecallTask extends TaskMeta {
  type: "recall";
  items: { q: string; hint: string }[];
}
export interface MatchTask extends TaskMeta {
  type: "match";
  pairs: { ko: string; gloss: string }[];
}
export interface BuildTask extends TaskMeta {
  type: "build";
  /** chips are given in correct order; the UI shuffles them. */
  items: { en: string; chips: string[] }[];
}
export interface ChoiceTask extends TaskMeta {
  type: "choice";
  items: { q: string; options: string[] }[];
}
export type Task = TranslateTask | RecallTask | MatchTask | BuildTask | ChoiceTask;
export type TaskType = Task["type"];

/** One uppercase letter; see ROLES. */
export type GlossRole = "S" | "T" | "O" | "V" | "P" | "C" | "Q" | "M" | "N";

export interface GlossPart {
  ko: string;
  role: GlossRole;
  gloss: string;
  /** The meaningful piece INSIDE the word — particle, tense marker, ending. */
  highlight: string;
}
export interface GlossBlock {
  parts: GlossPart[];
  en: string;
}

export interface Progress {
  score: number;
  note: string;
}

/** One marked item from a ::result block. */
export interface ResultRow {
  item: string;
  /** Only the literal "ok" (any case) counts as correct. */
  ok: boolean;
  /** On a wrong answer: what the tutor thinks the student mistook it for. */
  mistakenFor: string;
}

export interface ParsedMessage {
  body: string;
  /** Every ::words entry in the message; the first gloss of a term wins. */
  words: WordEntry[] | null;
  /** The LAST ::task block. */
  task: Task | null;
  /** Every ::gloss block, accumulated; each closes at its "=" line. */
  gloss: GlossBlock[] | null;
  /** The last ::result block. */
  results: ResultRow[] | null;
  /** The last ::confirmed block, first column of each row. May carry a
      leading "-" meaning "put this back". */
  confirmed: string[] | null;
  /** The last ::progress line. */
  progress: Progress | null;
}

export function parse(text: string): ParsedMessage;

/** Roles a gloss part can carry, and what the UI should do with each. */
export const ROLES: Record<GlossRole, string>;

/** State shapes accepted by answerText(), per task type. */
export type TranslateState = string[];
export type RecallState = string[];
export type MatchState = { pairs: { ko: string; gloss: string }[] };
export type BuildState = string[][];
export type ChoiceState = (number | null)[];
export type TaskState = TranslateState | RecallState | MatchState | BuildState | ChoiceState;

/** Turn a completed task back into the message the student sends.
    The state shape follows the task type, so these are overloads rather
    than one signature over a union.

    `letterBlock` is hangul.js letterCheck() output for a recall task — pass
    it, always. The tutor cannot see inside a syllable and will invent a
    diagnosis otherwise. Other task types ignore it. */
export function answerText(
  task: TranslateTask,
  state: TranslateState,
  lookups?: string[],
  letterBlock?: string,
): string;
export function answerText(
  task: RecallTask,
  state: RecallState,
  lookups?: string[],
  letterBlock?: string,
): string;
export function answerText(
  task: MatchTask,
  state: MatchState,
  lookups?: string[],
  letterBlock?: string,
): string;
export function answerText(
  task: BuildTask,
  state: BuildState,
  lookups?: string[],
  letterBlock?: string,
): string;
export function answerText(
  task: ChoiceTask,
  state: ChoiceState,
  lookups?: string[],
  letterBlock?: string,
): string;
export function answerText(
  task: Task,
  state: TaskState,
  lookups?: string[],
  letterBlock?: string,
): string;