import { homedir } from "os"
import * as git from "../git.ts"
import * as vm from "../vm.ts"
import * as state from "../state.ts"
import { reset, dim, bold, green, yellow, cyan, white } from "../fmt.ts"

export async function action(opts: { json?: boolean }) {
  const root = await git.repoRoot()
  const st = await state.load(root)
  const sessions = Object.values(st.sessions)

  // Discover prompts from Claude history for sessions that lack one
  const needsPrompt = sessions.filter(s => !s.prompt)
  if (needsPrompt.length > 0 && (await vm.status()) === "running") {
    try {
      const result = await vm.exec(homedir() + "/.sandlot", "cat /home/ubuntu/.claude/history.jsonl 2>/dev/null")
      if (result.exitCode === 0 && result.stdout) {
        const entries = result.stdout.split("\n").filter(Boolean).map(line => {
          try { return JSON.parse(line) } catch { return null }
        }).filter(Boolean)

        for (const s of needsPrompt) {
          const cPath = vm.containerPath(s.worktree)
          const match = entries.find((e: any) => e.project === cPath)
          if (match?.display) {
            s.prompt = match.display
          }
        }
      }
    } catch {}
  }

  if (opts.json) {
    console.log(JSON.stringify(sessions, null, 2))
    return
  }

  if (sessions.length === 0) {
    console.log("◆ No active sessions.")
    return
  }

  // Determine status for each session in parallel
  const statusEntries = await Promise.all(
    sessions.map(async (s): Promise<[string, string]> => {
      if (await vm.isClaudeActive(s.worktree, s.branch)) return [s.branch, "active"]
      const dirty = await git.isDirty(s.worktree)
      if (dirty) return [s.branch, "dirty"]
      const commits = await git.hasNewCommits(s.worktree)
      return [s.branch, commits ? "saved" : "idle"]
    })
  )
  const statuses = Object.fromEntries(statusEntries)

  if (opts.json) {
    const withStatus = sessions.map(s => ({ ...s, status: statuses[s.branch] }))
    console.log(JSON.stringify(withStatus, null, 2))
    return
  }

  const icons: Record<string, string> = { idle: `${dim}◌${reset}`, active: `${cyan}◯${reset}`, dirty: `${yellow}◎${reset}`, saved: `${green}●${reset}` }
  const branchColors: Record<string, string> = { idle: dim, active: cyan, dirty: yellow, saved: green }
  const branchWidth = Math.max(6, ...sessions.map((s) => s.branch.length))
  const cols = process.stdout.columns || 80
  const prefixWidth = branchWidth + 4

  console.log(`  ${dim}${"BRANCH".padEnd(branchWidth)}  PROMPT${reset}`)

  for (const s of sessions) {
    const prompt = (s.prompt ?? "").replace(/\n/g, " ")
    const status = statuses[s.branch]
    const icon = icons[status]
    const bc = branchColors[status]
    const maxPrompt = cols - prefixWidth
    const truncated = maxPrompt > 3 && prompt.length > maxPrompt ? prompt.slice(0, maxPrompt - 3) + "..." : prompt
    console.log(`${icon} ${bc}${s.branch.padEnd(branchWidth)}${reset}  ${dim}${truncated}${reset}`)
  }

  console.log(`\n${dim}◌ idle${reset} · ${cyan}◯ active${reset} · ${yellow}◎ unsaved${reset} · ${green}● saved${reset}`)
}