import { splitLines, autoClosingPairOpenings, autoClosingPairClosings } from "./utils";
import hashObject from "object-hash";

export type CompletionRequest = {
  filepath: string;
  language: string;
  text: string;
  position: number;
  manually?: boolean;
};

export type CompletionResponseChoice = {
  index: number;
  text: string;
  // Range of the text to be replaced when applying the completion.
  // The range should be limited to the current line.
  replaceRange: {
    start: number;
    end: number;
  };
};

export type CompletionResponse = {
  id: string;
  choices: CompletionResponseChoice[];
};

function isAtLineEndExcludingAutoClosedChar(suffix: string) {
  return suffix
    .trimEnd()
    .split("")
    .every((char) => autoClosingPairClosings.includes(char));
}

export class CompletionContext {
  filepath: string;
  language: string;
  text: string;
  position: number;

  prefix: string;
  suffix: string;
  prefixLines: string[];
  suffixLines: string[];

  // "default": the cursor is at the end of the line
  // "fill-in-line": the cursor is not at the end of the line, except auto closed characters
  //   In this case, we assume the completion should be a single line, so multiple lines completion will be dropped.
  mode: "default" | "fill-in-line";
  hash: string;

  constructor(request: CompletionRequest) {
    this.filepath = request.filepath;
    this.language = request.language;
    this.text = request.text;
    this.position = request.position;

    this.prefix = request.text.slice(0, request.position);
    this.suffix = request.text.slice(request.position);
    this.prefixLines = splitLines(this.prefix);
    this.suffixLines = splitLines(this.suffix);

    const lineEnd = isAtLineEndExcludingAutoClosedChar(this.suffixLines[0] ?? "");
    this.mode = lineEnd ? "default" : "fill-in-line";
    this.hash = hashObject({
      filepath: request.filepath,
      language: request.language,
      text: request.text,
      position: request.position,
    });
  }
}