import { createServerFn } from '@tanstack/react-start'
import { execSync } from 'node:child_process'

const REPO_PATH = process.env.GITUI_REPO_PATH || process.cwd()

function git(args: string): string {
  return execSync(`git ${args}`, {
    cwd: REPO_PATH,
    encoding: 'utf-8',
    maxBuffer: 10 * 1024 * 1024,
  }).trim()
}

export interface CommitInfo {
  hash: string
  shortHash: string
  author: string
  date: string
  message: string
}

export interface GitStatus {
  staged: Array<{ status: string; path: string }>
  unstaged: Array<{ status: string; path: string }>
  untracked: string[]
}

export const getLog = createServerFn({ method: 'POST' })
  .inputValidator((d: { count?: number; skip?: number }) => d)
  .handler(async ({ data }) => {
    const count = data.count ?? 50
    const skip = data.skip ?? 0
    const raw = git(
      `log --format="%H%x00%h%x00%an%x00%ai%x00%s" -n ${count} --skip=${skip}`,
    )
    if (!raw) return [] as CommitInfo[]
    return raw.split('\n').map((line): CommitInfo => {
      const [hash, shortHash, author, date, message] = line.split('\x00')
      return { hash, shortHash, author, date, message }
    })
  })

export const getTree = createServerFn({ method: 'POST' })
  .inputValidator((d: { ref?: string }) => d)
  .handler(async ({ data }) => {
    const ref = data.ref || 'HEAD'
    const raw = git(`ls-tree -r --name-only ${ref}`)
    return raw.split('\n').filter(Boolean)
  })

export const getFileContent = createServerFn({ method: 'POST' })
  .inputValidator((d: { ref: string; path: string }) => d)
  .handler(async ({ data }) => {
    return git(`show ${data.ref}:${data.path}`)
  })

export const getDiff = createServerFn({ method: 'POST' })
  .inputValidator((d: string) => d)
  .handler(async ({ data: hash }) => {
    return git(`show --format="" --patch ${hash}`)
  })

export const getWorkingDiff = createServerFn().handler(async () => {
  return git('diff')
})

export const getStagedDiff = createServerFn().handler(async () => {
  return git('diff --cached')
})

export const getStatus = createServerFn().handler(
  async (): Promise<GitStatus> => {
    const raw = git('status --porcelain')
    const staged: GitStatus['staged'] = []
    const unstaged: GitStatus['unstaged'] = []
    const untracked: string[] = []

    for (const line of raw.split('\n').filter(Boolean)) {
      const x = line[0]
      const y = line[1]
      const path = line.slice(3)

      if (x === '?') {
        untracked.push(path)
      } else {
        if (x !== ' ' && x !== '?') {
          staged.push({ status: x, path })
        }
        if (y !== ' ' && y !== '?') {
          unstaged.push({ status: y, path })
        }
      }
    }
    return { staged, unstaged, untracked }
  },
)

export const getBranches = createServerFn().handler(async () => {
  const current = git('branch --show-current')
  const all = git('branch --format="%(refname:short)"')
    .split('\n')
    .filter(Boolean)
  return { current, all }
})

export const getCommitDetail = createServerFn({ method: 'POST' })
  .inputValidator((d: string) => d)
  .handler(async ({ data: hash }) => {
    const info = git(
      `show --format="%H%x00%h%x00%an%x00%ae%x00%ai%x00%B" --stat ${hash}`,
    )
    const [header, ...rest] = info.split('\n\n')
    const [h, shortHash, author, email, date, ...msgParts] =
      header.split('\x00')
    const message = msgParts.join('\x00')
    const stats = rest.join('\n\n')
    return { hash: h, shortHash, author, email, date, message, stats }
  })