comment.ts

import { ValidationError } from '@changesets/errors'
import type {
  ComprehensiveRelease,
  ReleasePlan,
  VersionType,
} from '@changesets/types'
import type { Gitlab, MergeRequests } from '@gitbeaker/core'
import { captureException } from '@sentry/node'
import { humanId } from 'human-id'
import { markdownTable } from 'markdown-table'

import * as context from './context.js'
import { getChangedPackages } from './get-changed-packages.js'
import { getUsername } from './utils.js'

import { createApi } from './index.js'

const generatedByBotNote = 'Generated By Changesets GitLab Bot'

const getReleasePlanMessage = (releasePlan: ReleasePlan | null) => {
  if (!releasePlan) return ''

  const publishableReleases = releasePlan.releases.filter(
    (x): x is ComprehensiveRelease & { type: Exclude<VersionType, 'none'> } =>
      x.type !== 'none',
  )

  const table = markdownTable([
    ['Name', 'Type'],
    ...publishableReleases.map(x => [
      x.name,
      {
        major: 'Major',
        minor: 'Minor',
        patch: 'Patch',
      }[x.type],
    ]),
  ])

  return `<details><summary>This MR includes ${
    releasePlan.changesets.length > 0
      ? `changesets to release ${
          publishableReleases.length === 1
            ? '1 package'
            : `${publishableReleases.length} packages`
        }`
      : 'no changesets'
  }</summary>

  ${
    publishableReleases.length > 0
      ? table
      : "When changesets are added to this MR, you'll see the packages that this MR includes changesets for and the associated semver types"
  }

</details>`
}

const getAbsentMessage = (
  commitSha: string,
  addChangesetUrl: string,
  releasePlan: ReleasePlan | null,
) => `###  ⚠️  No Changeset found

Latest commit: ${commitSha}

Merging this MR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. **If these changes should result in a version bump, you need to add a changeset.**

${getReleasePlanMessage(releasePlan)}

[Click here to learn what changesets are, and how to add one](https://github.com/changesets/changesets/blob/master/docs/adding-a-changeset.md).

[Click here if you're a maintainer who wants to add a changeset to this MR](${addChangesetUrl})

__${generatedByBotNote}__
`

const getApproveMessage = (
  commitSha: string,
  addChangesetUrl: string,
  releasePlan: ReleasePlan | null,
) => `###  🦋  Changeset detected

Latest commit: ${commitSha}

**The changes in this MR will be included in the next version bump.**

${getReleasePlanMessage(releasePlan)}

Not sure what this means? [Click here  to learn what changesets are](https://github.com/changesets/changesets/blob/master/docs/adding-a-changeset.md).

[Click here if you're a maintainer who wants to add another changeset to this MR](${addChangesetUrl})

__${generatedByBotNote}__
`

const getNewChangesetTemplate = (changedPackages: string[], title: string) =>
  encodeURIComponent(`---
${changedPackages.map(x => `"${x}": patch`).join('\n')}
---

${title}
`)

const getNoteInfo = (api: Gitlab, mrIid: number | string) =>
  api.MergeRequestDiscussions.all(context.projectId, mrIid).then(
    async discussions => {
      for (const discussion of discussions) {
        if (!discussion.notes) {
          continue
        }

        const username = await getUsername(api)
        const changesetBotNote = discussion.notes.find(
          note =>
            note.author.username === username &&
            // We need to ensure the note is generated by us, but we don't have an app bot like GitHub
            // @see https://github.com/apps/changeset-bot
            note.body.includes(generatedByBotNote),
        )

        if (changesetBotNote) {
          return {
            discussionId: discussion.id,
            noteId: changesetBotNote.id,
          }
        }
      }
    },
  )

const hasChangesetBeenAdded = (
  changedFilesPromise: ReturnType<MergeRequests['changes']>,
) =>
  changedFilesPromise.then(files =>
    files.changes!.some(
      file =>
        file.new_file &&
        /^\.changeset\/.+\.md$/.test(file.new_path) &&
        file.new_path !== '.changeset/README.md',
    ),
  )

const getCommentFunctions = (api: Gitlab, commentType: string) => {
  if (commentType === 'discussion') {
    return {
      editComment: api.MergeRequestDiscussions.editNote.bind(
        api.MergeRequestDiscussions,
      ),
      createComment: api.MergeRequestDiscussions.create.bind(
        api.MergeRequestDiscussions,
      ),
    }
  }

  if (commentType === 'note') {
    return {
      editComment: api.MergeRequestNotes.edit.bind(api.MergeRequestNotes),
      createComment: api.MergeRequestNotes.create.bind(api.MergeRequestNotes),
    }
  }

  throw new Error(
    `Invalid comment type "${commentType}", should be "discussion" or "note"`,
  )
}

export const comment = async () => {
  const {
    CI_MERGE_REQUEST_IID,
    CI_MERGE_REQUEST_PROJECT_URL,
    CI_MERGE_REQUEST_SOURCE_BRANCH_NAME: mrBranch,
    CI_MERGE_REQUEST_SOURCE_BRANCH_SHA,
    CI_MERGE_REQUEST_TITLE,
    GITLAB_COMMENT_TYPE = 'discussion',
  } = process.env

  if (!mrBranch) {
    console.warn('[changesets-gitlab:comment] It should only be used on MR')
    return
  }

  if (mrBranch.startsWith('changeset-release')) {
    return
  }

  const api = createApi()

  let errFromFetchingChangedFiles = ''

  const mrIid = +CI_MERGE_REQUEST_IID!

  try {
    const latestCommitSha = CI_MERGE_REQUEST_SOURCE_BRANCH_SHA!
    const changedFilesPromise = api.MergeRequests.changes(
      context.projectId,
      mrIid,
    )

    const [noteInfo, hasChangeset, { changedPackages, releasePlan }] =
      await Promise.all([
        getNoteInfo(api, mrIid),
        hasChangesetBeenAdded(changedFilesPromise),
        getChangedPackages({
          changedFiles: changedFilesPromise.then(x =>
            x.changes!.map(x => x.new_path),
          ),
          api,
        }).catch((err: unknown) => {
          if (err instanceof ValidationError) {
            errFromFetchingChangedFiles = `<details><summary>💥 An error occurred when fetching the changed packages and changesets in this MR</summary>\n\n\`\`\`\n${err.message}\n\`\`\`\n\n</details>\n`
          } else {
            console.error(err)
            captureException(err)
          }
          return {
            changedPackages: ['@fake-scope/fake-pkg'],
            releasePlan: null,
          }
        }),
      ] as const)

    const addChangesetUrl = `${CI_MERGE_REQUEST_PROJECT_URL!}/new/${mrBranch}?file_name=.changeset/${humanId(
      {
        separator: '-',
        capitalize: false,
      },
    )}.md&file=${getNewChangesetTemplate(
      changedPackages,
      CI_MERGE_REQUEST_TITLE!,
    )}`

    const prComment =
      (hasChangeset
        ? getApproveMessage(latestCommitSha, addChangesetUrl, releasePlan)
        : getAbsentMessage(latestCommitSha, addChangesetUrl, releasePlan)) +
      errFromFetchingChangedFiles

    const { editComment, createComment } = getCommentFunctions(
      api,
      GITLAB_COMMENT_TYPE,
    )

    if (noteInfo != null) {
      return editComment(
        context.projectId,
        mrIid,
        // @ts-expect-error - https://github.com/jdalrymple/gitbeaker/pull/523#issuecomment-975276068
        noteInfo.discussionId,
        noteInfo.noteId,
        {
          body: prComment,
        },
      )
    }
    return createComment(context.projectId, mrIid, prComment)
  } catch (err: unknown) {
    console.error(err)
    throw err
  }
}