#!/usr/bin/env bash
#
# setup.sh - the one command: opencode + session pushing, from scratch, on this
#            Cloud Shell VM.
#
#   bash <(curl -fsSL https://<site>.pages.dev/setup.sh)
#
# It:
#   1. logs this VM into GitHub with a token you paste (or GH_TOKEN if already set)
#   2. installs opencode (once) and starts it in tmux, on port PORT
#   3. installs sessions.sh, creates new1 + new2 and the private repo, takes the
#      first snapshot and starts the 3-minute push daemon
#
# Safe to re-run: a running opencode, existing auth, repo, folders and daemon
# are all reused.
#
# Optional environment variables:
#   GH_TOKEN        GitHub token; when unset you are prompted to paste one
#                   (stdin only - never argv, a file or history)
#   PORT            opencode port                          [default: 4096]
#   OC_VERSION      opencode-ai npm version                [default: 1.18.35]
#   BACKUP_REPO     private repo name                      [default: cloudshell-sessions]
#   BACKUP_REMOTE   full remote URL; skips `gh repo create`
#   BACKUP_INTERVAL seconds between passes                 [default: 180]
#   IDLE_LIMIT      idle passes before pausing             [default: 3]
#
# NEVER add `set -x` to this script: it would echo GH_TOKEN.

set -euo pipefail

BASE_URL="${BASE_URL:-https://opencode-cloudshell-vwb6.pages.dev}"

log()  { printf '%s\n' "$*"; }
warn() { printf 'warning: %s\n' "$*" >&2; }
die()  { printf 'error: %s\n' "$*" >&2; exit 1; }

# Everything below assumes the Cloud Shell VM, not a laptop.
if [ ! -d /google/devshell ] && [ -z "${DEVSHELL_PROJECT_ID:-}" ]; then
  die "run this inside a Cloud Shell terminal.
  From your own machine use install.sh instead:
    bash <(curl -fsSL $BASE_URL/install.sh)"
fi

command -v tmux >/dev/null 2>&1 || die "tmux is missing on this VM."
command -v git  >/dev/null 2>&1 || die "git is missing on this VM."

tmp="$(mktemp -d)"
trap 'rm -rf "$tmp"' EXIT

fetch() {
  local name="$1"
  curl -fsSL "$BASE_URL/$name" -o "$tmp/$name" || die "could not download $BASE_URL/$name"
  bash -n "$tmp/$name" || die "$name failed its syntax check"
}

log "== 1/3  GitHub =="
if command -v gh >/dev/null 2>&1; then
  if [ -z "${GH_TOKEN:-}" ] && gh auth status >/dev/null 2>&1; then
    log "GitHub: already authenticated as $(gh api user --jq .login 2>/dev/null || echo unknown)."
  elif [ -z "${GH_TOKEN:-}" ] && [ ! -t 0 ]; then
    warn "gh is not authenticated and there is no terminal to prompt on."
    warn "set GH_TOKEN and run this command again."
  else
    if [ -z "${GH_TOKEN:-}" ]; then
      printf 'GitHub token (repo scope, input hidden): ' >&2
      IFS= read -rs token || token=""
      printf '\n' >&2
      [ -n "$token" ] || die "no token entered."
    else
      token="$GH_TOKEN"
    fi
    if printf '%s\n' "$token" | gh auth login --with-token; then
      unset token
      gh auth setup-git >/dev/null 2>&1 || warn "gh auth setup-git failed."
      log "GitHub: token accepted."
    else
      unset token
      die "GitHub rejected the token (needs 'repo' scope to create the private repo)."
    fi
  fi
else
  warn "the gh CLI is missing; sessions.sh needs it to create the private repo."
  warn "set BACKUP_REMOTE=<existing repo url> to skip repo creation."
fi

log ""
log "== 2/3  opencode =="
fetch cloudshell.sh
if bash "$tmp/cloudshell.sh" --status >/dev/null 2>&1; then
  log "opencode is already running; leaving it alone."
else
  # stdin from /dev/null so cloudshell.sh does not attach and block this script.
  bash "$tmp/cloudshell.sh" </dev/null
fi

log ""
log "== 3/3  session pushing =="
fetch sessions.sh
bash "$tmp/sessions.sh" </dev/null

log ""
log "Done. opencode is up and every new<N> folder is being pushed."
log "  sessions status:  ~/.local/bin/cloudshell-sessions --status"
log "  sessions log:     ~/.local/bin/cloudshell-sessions --logs"
log "  opencode:         tmux attach -t opencode   (Ctrl-B then D to leave)"