import type { ReleaseContext } from '#/src/utils/create-context.js'
import { formatDate } from '#/src/utils/format-date.js'
import type {
  ReleaseNoteCommit,
  ReleaseNotes,
  ReleaseNoteType,
} from '#/src/utils/release-notes/get-release-notes.js'

/**
 * Generate a Markdown string for the given release notes.
 */
export function toMarkdown(
  context: ReleaseContext,
  notes: ReleaseNotes,
): string {
  const markdown: string[] = []
  const releaseDate = formatDate(context.nextRelease.publishedAt)

  markdown.push(`## ${context.nextRelease.tag} (${releaseDate})`)

  const sections: Record<ReleaseNoteType, string[]> = {
    breaking: [],
    feat: [],
    fix: [],
  }

  for (const [noteType, commits] of notes) {
    const section = sections[noteType]

    if (!section) {
      continue
    }

    for (const commit of commits) {
      const releaseItem = createReleaseItem(commit, noteType === 'breaking')

      if (releaseItem) {
        section.push(...releaseItem)
      }
    }
  }

  if (sections.breaking.length > 0) {
    markdown.push('', '### ⚠️ BREAKING CHANGES')
    markdown.push(...sections.breaking)
  }

  if (sections.feat.length > 0) {
    markdown.push('', '### Features', '')
    markdown.push(...sections.feat)
  }

  if (sections.fix.length > 0) {
    markdown.push('', '### Bug Fixes', '')
    markdown.push(...sections.fix)
  }

  return markdown.join('\n')
}

function createReleaseItem(
  commit: ReleaseNoteCommit,
  includeCommitNotes: boolean = false,
): string[] {
  const { subject, scope, hash } = commit

  if (!subject) {
    return []
  }

  const commitLine: string[] = [
    [
      '-',
      scope && `**${scope}:**`,
      subject,
      `(${hash})`,
      printAuthors(commit.authors),
    ]
      .filter(Boolean)
      .join(' '),
  ]

  if (includeCommitNotes) {
    const notes = commit.notes.reduce<string[]>((all, note) => {
      return all.concat('', note.text)
    }, [])

    if (notes.length > 0) {
      commitLine.unshift('')
      commitLine.push(...notes)
    }
  }

  return commitLine
}

export function printAuthors(authors: Set<string>): string | undefined {
  if (authors.size === 0) {
    return undefined
  }

  return Array.from(authors)
    .map((login) => `@${login}`)
    .join(' ')
}