'use client'

import React from 'react'
import ReactMarkdown from 'react-markdown'
import { Avatar, AvatarFallback, AvatarImage } from '@/components/emcn'
import type { ChangelogEntry } from '@/app/changelog/components/changelog-content'

type Props = { initialEntries: ChangelogEntry[] }

function sanitizeContent(body: string): string {
  return body.replace(/&nbsp/g, '')
}

function stripContributors(body: string): string {
  let output = body
  output = output.replace(
    /(^|\n)#{1,6}\s*Contributors\s*\n[\s\S]*?(?=\n\s*\n|\n#{1,6}\s|$)/gi,
    '\n'
  )
  output = output.replace(
    /(^|\n)\s*(?:\*\*|__)?\s*Contributors\s*(?:\*\*|__)?\s*:?\s*\n[\s\S]*?(?=\n\s*\n|\n#{1,6}\s|$)/gi,
    '\n'
  )
  output = output.replace(
    /(^|\n)[-*+]\s*(?:@[A-Za-z0-9-]+(?:\s*,\s*|\s+))+@[A-Za-z0-9-]+\s*(?=\n)/g,
    '\n'
  )
  output = output.replace(
    /(^|\n)\s*(?:@[A-Za-z0-9-]+(?:\s*,\s*|\s+))+@[A-Za-z0-9-]+\s*(?=\n)/g,
    '\n'
  )
  return output
}

function isContributorsLabel(nodeChildren: React.ReactNode): boolean {
  return /^\s*contributors\s*:?\s*$/i.test(String(nodeChildren))
}

function stripPrReferences(body: string): string {
  return body.replace(/\s*\(\s*\[#\d+\]\([^)]*\)\s*\)/g, '').replace(/\s*\(\s*#\d+\s*\)/g, '')
}

function cleanMarkdown(body: string): string {
  const sanitized = sanitizeContent(body)
  const withoutContribs = stripContributors(sanitized)
  const withoutPrs = stripPrReferences(withoutContribs)
  return withoutPrs
}

function extractMentions(body: string): string[] {
  const matches = body.match(/@([A-Za-z0-9-]+)/g) ?? []
  return Array.from(new Set(matches.map((m) => m.slice(1))))
}

export default function ChangelogList({ initialEntries }: Props) {
  const [entries, setEntries] = React.useState<ChangelogEntry[]>(initialEntries)
  const [page, setPage] = React.useState<number>(1)
  const [loading, setLoading] = React.useState<boolean>(false)
  const [done, setDone] = React.useState<boolean>(false)

  const loadMore = async () => {
    if (loading || done) return
    setLoading(true)
    try {
      const nextPage = page + 1
      const res = await fetch(
        `https://api.github.com/repos/simstudioai/sim/releases?per_page=10&page=${nextPage}`,
        { headers: { Accept: 'application/vnd.github+json' } }
      )
      const releases: any[] = await res.json()
      const mapped: ChangelogEntry[] = (releases || [])
        .filter((r) => !r.prerelease)
        .map((r) => ({
          tag: r.tag_name,
          title: r.name || r.tag_name,
          content: sanitizeContent(String(r.body || '')),
          date: r.published_at,
          url: r.html_url,
          contributors: extractMentions(String(r.body || '')),
        }))

      if (mapped.length === 0) {
        setDone(true)
      } else {
        setEntries((prev) => [...prev, ...mapped])
        setPage(nextPage)
      }
    } catch {
      setDone(true)
    } finally {
      setLoading(false)
    }
  }

  return (
    <div className='space-y-10'>
      {entries.map((entry) => (
        <div key={entry.tag}>
          <div className='flex items-center justify-between gap-4'>
            <div className='flex items-center gap-2'>
              <div className='font-[500] text-[var(--landing-text)] text-lg tracking-tight'>
                {entry.tag}
              </div>
              {entry.contributors && entry.contributors.length > 0 && (
                <div className='-space-x-2 flex'>
                  {entry.contributors.slice(0, 5).map((contributor) => (
                    <a
                      key={contributor}
                      href={`https://github.com/${contributor}`}
                      target='_blank'
                      rel='noreferrer noopener'
                      aria-label={`View @${contributor} on GitHub`}
                      title={`@${contributor}`}
                      className='block'
                    >
                      <Avatar className='size-6 ring-2 ring-[var(--landing-bg)]'>
                        <AvatarImage
                          src={`https://avatars.githubusercontent.com/${contributor}`}
                          alt={`@${contributor}`}
                          className='hover:z-10'
                        />
                        <AvatarFallback>{contributor.slice(0, 2).toUpperCase()}</AvatarFallback>
                      </Avatar>
                    </a>
                  ))}
                  {entry.contributors.length > 5 && (
                    <div className='relative flex size-6 items-center justify-center rounded-full bg-[var(--landing-bg-elevated)] text-[var(--landing-text)] text-micro ring-2 ring-[var(--landing-bg)] hover:z-10'>
                      +{entry.contributors.length - 5}
                    </div>
                  )}
                </div>
              )}
            </div>
            <div className='text-[var(--landing-text-muted)] text-xs'>
              {new Date(entry.date).toLocaleDateString('en-US', {
                year: 'numeric',
                month: 'short',
                day: 'numeric',
              })}
            </div>
          </div>

          <div className='max-w-none'>
            <ReactMarkdown
              components={{
                h2: ({ children, ...props }) =>
                  isContributorsLabel(children) ? null : (
                    <h3
                      className='mt-5 mb-2 font-[500] text-[var(--landing-text)] text-small tracking-tight'
                      {...props}
                    >
                      {children}
                    </h3>
                  ),
                h3: ({ children, ...props }) =>
                  isContributorsLabel(children) ? null : (
                    <h4
                      className='mt-4 mb-1 font-[500] text-[var(--landing-text)] text-small tracking-tight'
                      {...props}
                    >
                      {children}
                    </h4>
                  ),
                ul: ({ children, ...props }) => (
                  <ul className='mt-2 mb-3 space-y-1.5' {...props}>
                    {children}
                  </ul>
                ),
                li: ({ children, ...props }) => {
                  const text = String(children)
                  if (/^\s*contributors\s*:?\s*$/i.test(text)) return null
                  return (
                    <li
                      className='text-[var(--landing-text-muted)] text-small leading-relaxed'
                      {...props}
                    >
                      {children}
                    </li>
                  )
                },
                p: ({ children, ...props }) =>
                  /^\s*contributors\s*:?\s*$/i.test(String(children)) ? null : (
                    <p
                      className='mb-3 text-[var(--landing-text-muted)] text-small leading-relaxed'
                      {...props}
                    >
                      {children}
                    </p>
                  ),
                strong: ({ children, ...props }) => (
                  <strong className='font-[500] text-[var(--landing-text)]' {...props}>
                    {children}
                  </strong>
                ),
                code: ({ children, ...props }) => (
                  <code
                    className='rounded bg-[var(--landing-bg-elevated)] px-1 py-0.5 font-mono text-[var(--landing-text)] text-xs'
                    {...props}
                  >
                    {children}
                  </code>
                ),
                img: () => null,
                a: ({ className, ...props }: any) => (
                  <a
                    {...props}
                    className={`underline ${className ?? ''}`}
                    target='_blank'
                    rel='noreferrer'
                  />
                ),
              }}
            >
              {cleanMarkdown(entry.content)}
            </ReactMarkdown>
          </div>
        </div>
      ))}

      {!done && (
        <div>
          <button
            type='button'
            onClick={loadMore}
            disabled={loading}
            className='rounded-[5px] border border-[var(--landing-border-strong)] px-3 py-1.5 text-[var(--landing-text)] text-small transition-colors hover:bg-[var(--landing-bg-elevated)] disabled:opacity-60'
          >
            {loading ? 'Loading…' : 'Show more'}
          </button>
        </div>
      )}
    </div>
  )
}
