import * as d3 from "d3";
import { responsesSheetId, responsesSheetName } from "../config";

export const skills: { [key: string]: number } = {
  "Keine Kenntnisse": 0,
  "Geringe Kenntnisse": 1,
  "Grundlegende Kenntnisse": 2,
  "Gute Kenntnisse": 3,
  "Sehr fundierte Kenntnisse": 4,
};

function mapSkillToNumber(skill: string): number {
  return skills[skill] !== undefined ? skills[skill] : -1;
}

export interface ResponseData {
  timestamp: number;
  question: string;
  response: number;
}

export function parseCSV(csv: string): ResponseData[] {
  const rowConverter = (row: d3.DSVRowString): ResponseData[] => {
    const responses: { [key: string]: number } = {};
    Object.keys(row).forEach((key) => {
      // Likert scale responses have their group name in square brackets at the end of the column name
      const m = key.match(/\[([^\]]+)\]$/);
      if (m) {
        const category = m[1];
        responses[category] = mapSkillToNumber(row[key]);
      }
    });
    return Object.entries(responses).flatMap(([category, response]) => ({
      timestamp: new Date(row["Timestamp"]).getTime(),
      question: category,
      response: response,
    }));
  };
  const rows = d3.csvParse(csv, rowConverter);
  return rows.flatMap((row) => row);
}

export function fetchGoogleSheet() {
  const url = `https://docs.google.com/spreadsheets/d/${responsesSheetId}/gviz/tq?tqx=out:csv&sheet=${responsesSheetName}`;
  return fetch(url)
    .then((response) => {
      if (!response.ok) {
        throw new Error(`HTTP error! status: ${response.status}`);
      }
      return response.text();
    })
    .then((csv) => {
      return parseCSV(csv);
    });
}