#!/usr/bin/env bash
# tokenfund: your agent keeps working on 20vision/hide-and-clone until your limit. Stop any time with Ctrl-C.
# The agent runs as a separate computer user with no root and no access to your files, inside Claude Code's own sandbox.
# Your GitHub login stays with you: this script opens the pull requests, and the agent never sees that login.
set -uo pipefail
API=https://tokenfund.myclawn.com; SLUG='20vision-hide-and-clone'; REPO='20vision/hide-and-clone'; BUDGET=100000; MODEL=''
say() { printf '\n\033[1;35mtokenfund\033[0m %s\n' "$*"; }
die() { say "$*"; exit 1; }
for c in git curl gh claude; do command -v "$c" >/dev/null || die "Please install $c first."; done
gh auth status >/dev/null 2>&1 || die "Please run: gh auth login. Then press + again."
WORK="$(cd "$(mktemp -d)" && pwd -P)"
P="$WORK/project"
OS="$(uname -s)"
W=tokenfund
as_w() { sudo -n -iu "$W" "$@"; }
install_worker() {
  say "First run: creating a separate user called $W, with no root and no access to your files. This asks for your password once."
  sudo -v || die "Nothing was changed."
  if [ "$OS" = Linux ]; then
    for c in bwrap socat; do command -v "$c" >/dev/null || die "Please install bubblewrap and socat first, then press + again."; done
    id "$W" >/dev/null 2>&1 || sudo useradd --system --create-home --home-dir "/var/lib/$W" --shell /bin/bash "$W" || die "Could not create the user."
    sudo chmod 700 "/var/lib/$W"
    if [ -d /etc/apparmor.d ] && [ ! -f /etc/apparmor.d/bwrap ] && [ "$(cat /proc/sys/kernel/apparmor_restrict_unprivileged_userns 2>/dev/null)" = 1 ]; then
      printf 'abi <abi/4.0>,\ninclude <tunables/global>\nprofile bwrap /usr/bin/bwrap flags=(unconfined) {\n  userns,\n  include if exists <local/bwrap>\n}\n' | sudo tee /etc/apparmor.d/bwrap >/dev/null
      sudo apparmor_parser -r /etc/apparmor.d/bwrap
    fi
    [ "$(stat -c %a "$HOME" | cut -c3)" = 0 ] || say "Note: other users can read your home folder. To close that, run: chmod o-rwx ~"
  elif [ "$OS" = Darwin ]; then
    id "$W" >/dev/null 2>&1 || sudo sysadminctl -addUser "$W" -home "/Users/$W" -password "$(openssl rand -hex 24)" >/dev/null 2>&1 || die "Could not create the user."
    sudo createhomedir -c -u "$W" >/dev/null 2>&1
  else
    die "This system isn't supported yet."
  fi
  echo "$(id -un) ALL=($W) NOPASSWD: ALL" | sudo tee "/etc/sudoers.d/$W" >/dev/null; sudo chmod 440 "/etc/sudoers.d/$W"
  as_w bash -c 'curl -fsSL https://claude.ai/install.sh | bash' >/dev/null 2>&1 || die "Could not install Claude Code for the $W user."
}
as_w true 2>/dev/null && as_w test -x .local/bin/claude || install_worker
if ! as_w .local/bin/claude auth status >/dev/null 2>&1; then
  say "Log in once for the $W user. It's the same Claude account, but your own files stay out of reach."
  sudo -iu "$W" .local/bin/claude auth login || die "Login didn't finish."
fi
SETTINGS='{"sandbox":{"enabled":true,"failIfUnavailable":true,"allowUnsandboxedCommands":false,"autoAllowBashIfSandboxed":true,"filesystem":{"denyRead":["~/"],"allowRead":["."]},"network":{"allowedDomains":["registry.npmjs.org","pypi.org","files.pythonhosted.org","crates.io","static.crates.io","index.crates.io","proxy.golang.org"]}}}'
RUN="runs/$SLUG-$$"
git clone --quiet --depth 50 "https://github.com/$REPO" "$P" || die "Could not download the project."
cd "$P" || exit 1
# Connects your GitHub account with a temporary gist. Your GitHub login is never sent to us.
TF_ID="$HOME/.config/tokenfund/key"
if [ ! -s "$TF_ID" ]; then
  NONCE="$(curl -fsS -X POST "$API/api/id/start")" || die "The site can't be reached."
  GIST_URL="$(printf '%s\n' "$NONCE" | gh gist create -f tokenfund-proof.txt - 2>/dev/null)" || die "Please run: gh auth refresh -s gist. Then try again."
  GIST="${GIST_URL##*/}"
  sleep 2
  KEY="$(curl -fsS -X POST "$API/api/id/verify?gist=$GIST&nonce=$NONCE&login=$(gh api user -q .login)")"; RC=$?
  gh api -X DELETE "gists/$GIST" >/dev/null 2>&1
  [ "$RC" = 0 ] && [ -n "$KEY" ] || die "Could not verify your GitHub account. Try again in a minute."
  mkdir -p "$(dirname "$TF_ID")"; (umask 077; printf '%s' "$KEY" > "$TF_ID")
  say "GitHub account connected."
fi
TF_KEY="$(cat "$TF_ID")"

S=""
release() { [ -n "$S" ] && curl -fsS -m 10 -X POST "$API/api/release/$S" >/dev/null 2>&1; S=""; }
trap 'release; as_w rm -rf "$RUN"; say "Stopped. Tokens used: $USED"; exit 0' INT TERM
USED=0; PRS=0; EMPTY=0; FAILS=0
FORK=""
if [ "$BUDGET" -gt 0 ]; then say "Working on $REPO up to $BUDGET tokens. Press Ctrl-C to stop."; else say "Working on $REPO with no limit. Press Ctrl-C to stop."; fi
while :; do
  TURNS=40
  if [ "$BUDGET" -gt 0 ]; then
    LEFT=$((BUDGET-USED))
    [ "$LEFT" -lt 30000 ] && break
    TURNS=$((LEFT/8000)); [ "$TURNS" -lt 4 ] && TURNS=4; [ "$TURNS" -gt 40 ] && TURNS=40
  fi
  git fetch --quiet --depth 50 origin HEAD && git reset --quiet --hard FETCH_HEAD && git clean -fdxq
  # The agent gets a fresh copy in its own account, so nothing it writes runs or lands here unchecked.
  as_w bash -c "rm -rf '$RUN' && mkdir -p runs && git clone --quiet --depth 1 'https://github.com/$REPO' '$RUN' && find '$RUN' -type l -not -path '*/.git/*' -delete" || die "Could not prepare the project."
  S="$(curl -fsS -X POST -H "x-tf-key: $TF_KEY" "$API/api/session/$SLUG?sha=$(git rev-parse HEAD)")" || die "This project is closed, your account is banned, or the site can't be reached."
  M=(); [ -n "$MODEL" ] && M=(--model "$MODEL")
  ARGS=(-p "Call the tokenfund start_session tool with project $SLUG and session $S, then follow what it returns." ${M[@]+"${M[@]}"} \
    --setting-sources "" --settings "$SETTINGS" --strict-mcp-config --permission-mode dontAsk \
    --mcp-config "{\"mcpServers\":{\"tokenfund\":{\"type\":\"http\",\"url\":\"$API/mcp\"}}}" \
    --tools "Bash,Read,Edit,Write,Glob,Grep" \
    --allowedTools "mcp__tokenfund" "Bash" "Read(./**)" "Edit(./**)" "Write(./**)" \
    --max-turns "$TURNS" --output-format json)
  # Sent over stdin, because a login shell through sudo drops empty arguments.
  { printf 'cd %q && exec ~/.local/bin/claude' "$RUN"; printf ' %q' "${ARGS[@]}"; printf ' < /dev/null > ~/%q 2> ~/%q\n' "$RUN.json" "$RUN.err"; } | as_w bash -s
  as_w cat "$RUN.json" > "$WORK/run.json" 2>/dev/null
  as_w cat "$RUN.err" > "$WORK/run.err" 2>/dev/null
  T="$(curl -fsS -m 30 --data-binary @"$WORK/run.json" "$API/api/usage/$S" 2>/dev/null)"
  case "$T" in ''|*[!0-9]*) T=0 ;; esac
  USED=$((USED+T))
  if [ "$T" = 0 ]; then
    release; FAILS=$((FAILS+1))
    [ "$FAILS" -ge 2 ] && { sed -n 1,5p "$WORK/run.err" >&2; die "The agent couldn't run. Check your Claude Code login."; }
    continue
  fi
  FAILS=0
  if ! as_w test -f "$RUN/.tokenfund-pr.md"; then
    release; EMPTY=$((EMPTY+1)); say "No finished change this round. Tokens used: $USED"
    [ "$EMPTY" -ge 2 ] && { curl -fsS -m 10 -X POST -H "x-tf-key: $TF_KEY" "$API/api/idle/$SLUG" >/dev/null 2>&1; say "Nothing more to do right now."; break; }
    continue
  fi
  EMPTY=0
  as_w cat "$RUN/.tokenfund-pr.md" | head -c 20000 > "$WORK/pr.md"
  TITLE="$(head -n1 "$WORK/pr.md" | cut -c1-70)"; BODY="$(tail -n +2 "$WORK/pr.md")"
  as_w bash -c "cd '$RUN' && rm -f .tokenfund-pr.md && git add -A && git diff --cached --binary" > "$WORK/change.patch"
  if grep -qE '^(new file mode|old mode|new mode|deleted file mode) 120000' "$WORK/change.patch" || ! git apply --index "$WORK/change.patch" 2>/dev/null; then
    git reset --quiet --hard; release; say "Blocked a change that failed the safety check. It was not sent."; continue
  fi
  if git diff --cached --quiet; then release; continue; fi
  # Last check before anything leaves this computer.
  if git diff --cached --name-only | grep -qE '^(\.github/workflows/|\.claude/|\.mcp\.json|\.git)' \
    || [ "$(git diff --cached --numstat | awk '{s+=$1+$2} END {print s+0}')" -gt 3000 ] \
    || git diff --cached | grep -qE 'BEGIN [A-Z ]*PRIVATE KEY|sk-ant-|ghp_[A-Za-z0-9]{20}|github_pat_|AKIA[0-9A-Z]{16}|\.claude/\.credentials'; then
    release; say "Blocked a change that failed the safety check. It was not sent."; continue
  fi
  git -c user.useConfigOnly=false commit --quiet --no-verify -m "${TITLE:-tokenfund contribution}"
  if [ -z "$FORK" ]; then
    gh repo fork "$REPO" --remote --remote-name tokenfund-fork >/dev/null 2>&1
    FORK=origin; git remote | grep -q '^tokenfund-fork$' && FORK=tokenfund-fork
  fi
  ME="$(gh api user -q .login)"
  if git push --quiet "$FORK" "HEAD:refs/heads/tokenfund-$S" 2>/dev/null \
    && URL="$(gh pr create --repo "$REPO" --head "$ME:tokenfund-$S" --title "${TITLE:-tokenfund contribution}" --body "$BODY

Contributed via tokenfund.myclawn.com · session $S")"; then
    curl -fsS -m 30 -X POST "$API/api/receipt/$S?pr=$URL" >/dev/null 2>&1
    S=""; PRS=$((PRS+1)); say "Opened $URL · Tokens used: $USED"
  else
    release; say "Could not open the pull request. Trying the next task."
  fi
done
as_w rm -rf "$RUN" "$RUN.json" "$RUN.err"
say "Done. $PRS pull requests, $USED tokens. Thank you!"