/* PEG API Types */
export declare function parse(input: string, options?: Options): GIFTQuestion[];

export declare class SyntaxError extends Error {
  location: LocationRange;
  expected: Expectation[];
  found: string | null;
  name: string;
  message: string;
}

interface Options {
  filename?: string;
  startRule?: string;
  tracer?: any;
  [key: string]: any;
}

export interface Location {
  line: number;
  column: number;
  offset: number;
}

export interface LocationRange {
  start: Location;
  end: Location;
}

export interface LiteralExpectation {
  type: "literal";
  text: string;
  ignoreCase: boolean;
}

export interface ClassParts extends Array<string | ClassParts> {}

export interface ClassExpectation {
  type: "class";
  parts: ClassParts;
  inverted: boolean;
  ignoreCase: boolean;
}

export interface AnyExpectation {
  type: "any";
}

export interface EndExpectation {
  type: "end";
}

export interface OtherExpectation {
  type: "other";
  description: string;
}

export type Expectation =
  | LiteralExpectation
  | ClassExpectation
  | AnyExpectation
  | EndExpectation
  | OtherExpectation;

/* GIFT Question Types */
export type QuestionType =
  | "Description"
  | "Category"
  | "MC"
  | "Numerical"
  | "Short"
  | "Essay"
  | "TF"
  | "Matching";

export type FormatType = "moodle" | "html" | "markdown" | "plain";
export type NumericalType = "simple" | "range" | "high-low";

export interface TextFormat {
  format: FormatType;
  text: string;
}

export interface NumericalFormat {
  type: NumericalType;
  number?: number;
  range?: number;
  numberHigh?: number;
  numberLow?: number;
}

export interface TextChoice {
  isCorrect: boolean;
  weight: number | null;
  text: TextFormat;
  feedback: TextFormat | null;
}

export interface NumericalChoice {
  isCorrect: boolean;
  weight: number | null;
  text: NumericalFormat;
  feedback: TextFormat | null;
}

interface Question {
  id?: string | null;
  tags?: string[] | null;
  type: QuestionType;
  title: string | null;
  stem: TextFormat;
  hasEmbeddedAnswers: boolean;
  globalFeedback: TextFormat | null;
}

export interface Description {
  id?: string | null;
  tags?: string[] | null;
  type: Extract<QuestionType, "Description">;
  title: string | null;
  stem: TextFormat;
  hasEmbeddedAnswers: boolean;
}

export interface Category {
  id?: string | null;
  tags?: string[] | null;
  type: Extract<QuestionType, "Category">;
  title: string;
}

export interface MultipleChoice extends Question {
  type: Extract<QuestionType, "MC">;
  choices: TextChoice[];
}

export interface ShortAnswer extends Question {
  type: Extract<QuestionType, "Short">;
  choices: TextChoice[];
}

export interface Numerical extends Question {
  type: Extract<QuestionType, "Numerical">;
  choices: NumericalChoice[] | NumericalFormat;
}

export interface Essay extends Question {
  type: Extract<QuestionType, "Essay">;
}

export interface TrueFalse extends Question {
  type: Extract<QuestionType, "TF">;
  isTrue: boolean;
  trueFeedback: TextFormat | null;
  falseFeedback: TextFormat | null;
}

export interface Matching extends Question {
  type: Extract<QuestionType, "Matching">;
  matchPairs: Match[];
}

export interface Match {
  subquestion: TextFormat;
  subanswer: string;
}

export type GIFTQuestion =
  | Description
  | Category
  | MultipleChoice
  | ShortAnswer
  | Numerical
  | Essay
  | TrueFalse
  | Matching;