import gql from 'graphql-tag'
import Joi from 'joi'
import dayjs from 'dayjs'
import { pathParam, queryParam } from '../index.js'
import { parseDate } from '../date.js'
import { metric, maybePluralize } from '../text-formatters.js'
import { nonNegativeInteger } from '../validators.js'
import { GithubAuthV4Service } from './github-auth-service.js'
import {
  documentation as githubDocumentation,
  transformErrors,
} from './github-helpers.js'

const description = `
This badge is designed for projects hosted on GitHub which are
participating in
[Hacktoberfest](https://hacktoberfest.digitalocean.com),
an initiative to encourage participating in open-source projects. The
badge can be added to the project readme to encourage potential
contributors to review the suggested issues and to celebrate the
contributions that have already been made.
The badge displays three pieces of information:

- The number of suggested issues. By default this will count open
  issues with the <strong>hacktoberfest</strong> label, however you
  can pick a different label (e.g.
  \`?suggestion_label=good%20first%20issue\`).
- The number of pull requests opened in October. This excludes any
  PR with the <strong>invalid</strong> label.
- The number of days left of October.

${githubDocumentation}
`

const schema = Joi.object({
  data: Joi.object({
    repository: Joi.object({
      issues: Joi.object({
        totalCount: nonNegativeInteger,
      }).required(),
    }).required(),
    search: Joi.object({
      issueCount: nonNegativeInteger,
    }).required(),
  }).required(),
}).required()

const queryParamSchema = Joi.object({
  suggestion_label: Joi.string(),
}).required()

export default class GithubHacktoberfestCombinedStatus extends GithubAuthV4Service {
  static category = 'issue-tracking'
  static route = {
    base: 'github/hacktoberfest',
    pattern: ':year(2019|2020|2021|2022|2023|2024)/:user/:repo',
    queryParamSchema,
  }

  static openApi = {
    '/github/hacktoberfest/{year}/{user}/{repo}': {
      get: {
        summary: 'GitHub Hacktoberfest combined status',
        description,
        parameters: [
          pathParam({
            name: 'year',
            example: '2024',
            schema: { type: 'string', enum: this.getEnum('year') },
          }),
          pathParam({ name: 'user', example: 'tmrowco' }),
          pathParam({ name: 'repo', example: 'tmrowapp-contrib' }),
          queryParam({ name: 'suggestion_label', example: 'help wanted' }),
        ],
      },
    },
  }

  static defaultBadgeData = { label: 'hacktoberfest', color: 'orange' }

  static render({
    suggestedIssueCount,
    contributionCount,
    daysLeft,
    daysToStart,
    year,
    hasStarted = true,
  }) {
    if (!hasStarted) {
      return {
        message: `${daysToStart} ${maybePluralize(
          'day',
          daysToStart,
        )} till kickoff!`,
      }
    }
    if (daysLeft === undefined) {
      // The global cutoff time is 11/1 noon UTC.
      // https://github.com/badges/shields/pull/4109#discussion_r330782093
      // We want to show "1 day left" on the last day so we add 1.
      daysLeft = parseDate(`${year}-11-01 12:00:00 Z`).diff(dayjs(), 'days') + 1
    }
    if (daysLeft < 0) {
      return {
        message: `is over! (${metric(contributionCount)} ${maybePluralize(
          'PR',
          contributionCount,
        )} opened)`,
      }
    }
    const message =
      [
        suggestedIssueCount
          ? `${metric(suggestedIssueCount)} ${maybePluralize(
              'open issue',
              suggestedIssueCount,
            )}`
          : '',
        contributionCount
          ? `${metric(contributionCount)} ${maybePluralize(
              'PR',
              contributionCount,
            )}`
          : '',
        daysLeft > 0
          ? `${daysLeft} ${maybePluralize('day', daysLeft)} left`
          : '',
      ]
        .filter(Boolean)
        .join(', ') || 'is over!'

    return { message }
  }

  async fetch({ user, repo, year, suggestionLabel = 'hacktoberfest' }) {
    const isValidOctoberPR = [
      `repo:${user}/${repo}`,
      'is:pr',
      `created:${year}-10-01..${year}-10-31`,
      '-label:invalid',
    ]
      .filter(Boolean)
      .join(' ')
    const {
      data: {
        repository: {
          issues: { totalCount: suggestedIssueCount },
        },
        search: { issueCount: contributionCount },
      },
    } = await this._requestGraphql({
      query: gql`
        query (
          $user: String!
          $repo: String!
          $suggestionLabel: String!
          $isValidOctoberPR: String!
        ) {
          repository(owner: $user, name: $repo) {
            issues(states: [OPEN], labels: [$suggestionLabel]) {
              totalCount
            }
          }
          search(query: $isValidOctoberPR, type: ISSUE, last: 0) {
            issueCount
          }
        }
      `,
      variables: {
        user,
        repo,
        suggestionLabel,
        isValidOctoberPR,
      },
      schema,
      transformErrors,
    })
    return {
      suggestedIssueCount,
      contributionCount,
    }
  }

  static getCalendarPosition(year) {
    const daysToStart = parseDate(`${year}-10-01 00:00:00 Z`).diff(
      dayjs(),
      'days',
    )
    const isBefore = daysToStart > 0
    return { daysToStart, isBefore }
  }

  async handle({ user, repo, year }, { suggestion_label: suggestionLabel }) {
    const { isBefore, daysToStart } =
      this.constructor.getCalendarPosition(+year)
    if (isBefore) {
      return this.constructor.render({ hasStarted: false, daysToStart, year })
    }

    const { suggestedIssueCount, contributionCount } = await this.fetch({
      user,
      repo,
      year,
      suggestionLabel,
    })
    return this.constructor.render({
      suggestedIssueCount,
      contributionCount,
      year,
    })
  }
}