export type VariableTermKind = "constant" | "variable";

export interface VariableParenthesisTerm {
  kind: VariableTermKind;
  coefficient: number;
  variable?: "x";
}

export interface DistributedVariableTerm {
  kind: VariableTermKind;
  coefficient: number;
  variable?: "x";
  latex: string;
}

export interface VariableTermChoice {
  id: string;
  coefficient: number;
  variable?: "x";
  latex: string;
}

export interface VariableParenthesisProblem {
  id: string;
  key: string;
  multiplier: number;
  operator: "+" | "-";
  firstTerm: VariableParenthesisTerm;
  secondTerm: VariableParenthesisTerm;
  correctTerms: [DistributedVariableTerm, DistributedVariableTerm];
  choices: [VariableTermChoice[], VariableTermChoice[]];
  latexBefore: string;
  latexAfter: string;
}

export interface VariableUserAnswer {
  selectedChoiceIds: [string | null, string | null];
}

export interface VariableGradeResult {
  correct: boolean;
  userAnswer: [DistributedVariableTerm | null, DistributedVariableTerm | null];
  correctAnswer: [DistributedVariableTerm, DistributedVariableTerm];
}