#!/usr/bin/env bash
set -uo pipefail

STEP_NAMES=()
STEP_STATUS=()
STEP_DETAIL=()

step_ok()   { STEP_NAMES+=("$1"); STEP_STATUS+=("OK");       STEP_DETAIL+=("${2:-}"); echo "[OK]       $1"; }
step_skip() { STEP_NAMES+=("$1"); STEP_STATUS+=("SKIPPED");  STEP_DETAIL+=("${2:-}"); echo "[SKIPPED]  $1 - ${2:-}"; }
step_fail() { STEP_NAMES+=("$1"); STEP_STATUS+=("FAILED");   STEP_DETAIL+=("${2:-}"); echo "[FAILED]   $1 - ${2:-}"; }

section() { echo; echo "== $1 =="; }

print_summary() {
  echo
  echo "===================== summary ====================="
  local any_failed=0
  for i in "${!STEP_NAMES[@]}"; do
    printf '[%-8s] %s\n' "${STEP_STATUS[$i]}" "${STEP_NAMES[$i]}"
    [ -n "${STEP_DETAIL[$i]}" ] && printf '            %s\n' "${STEP_DETAIL[$i]}"
    [ "${STEP_STATUS[$i]}" = "FAILED" ] && any_failed=1
  done
  echo "====================================================="
  if [ "$any_failed" = 1 ]; then
    echo "One or more steps failed. Fix the issue above and re-run this script -"
    echo "already-completed steps are safe to skip and will not be repeated."
    exit 1
  fi
  echo "All steps OK or already satisfied."
}

# ---------- phase 0: environment ----------

preflight_env() {
  section "preflight: environment"
  if [ "$(id -u)" = "0" ]; then
    step_fail "environment check" "do not run as root - script uses sudo for the specific commands that need it"
    print_summary
    exit 1
  fi
  if ! grep -qi '^ID=debian' /etc/os-release 2>/dev/null; then
    step_fail "environment check" "this script targets Debian; /etc/os-release did not report ID=debian"
    print_summary
    exit 1
  fi
  step_ok "environment check"
}

# ---------- phase 0.1: config ----------

gather_config() {
  section "config"
  if [ -z "${FORGEJO_URL:-}" ]; then
    read -rp "Forgejo instance URL (e.g. https://git.example.com): " FORGEJO_URL
  fi
  FORGEJO_URL="${FORGEJO_URL%/}"

  if [ -z "${KEY_NAME:-}" ]; then
    read -rp "Label for this device's SSH key [travel-laptop]: " KEY_NAME
  fi
  KEY_NAME="${KEY_NAME:-travel-laptop}"
  KEYFILE="$HOME/.ssh/id_ed25519_${KEY_NAME}"

  step_ok "config gathered" "FORGEJO_URL=$FORGEJO_URL KEY_NAME=$KEY_NAME"
}

# ---------- phase 0.2: connectivity preflight ----------

check_url() {
  local name="$1" url="$2"
  if curl -fsS --max-time 5 -o /dev/null "$url"; then
    step_ok "reachable: $name"
  else
    step_fail "reachable: $name" "curl could not reach $url"
  fi
}

preflight_connectivity() {
  section "preflight: connectivity"
  check_url "Debian mirrors"      "https://deb.debian.org"
  check_url "Tailscale install"   "https://pkgs.tailscale.com"
  check_url "uv installer"        "https://astral.sh"
  check_url "Firefox extensions"  "https://addons.mozilla.org"
  check_url "VS Code repo"        "https://packages.microsoft.com"
  check_url "Forgejo instance"    "$FORGEJO_URL"

  for i in "${!STEP_NAMES[@]}"; do
    if [ "${STEP_STATUS[$i]}" = "FAILED" ]; then
      echo
      echo "Connectivity check failed for one or more dependencies (see above)."
      echo "Fix connectivity and re-run before continuing."
      print_summary
      exit 1
    fi
  done
}

# ---------- phase 1: base packages ----------

install_packages() {
  section "base packages"

  if command -v tailscale >/dev/null 2>&1; then
    step_skip "tailscale package" "already installed"
  else
    if curl -fsSL https://tailscale.com/install.sh | sh >/tmp/tailscale-install.log 2>&1; then
      step_ok "tailscale package"
    else
      step_fail "tailscale package" "see /tmp/tailscale-install.log"
    fi
  fi

  if [ ! -f /etc/apt/keyrings/microsoft.gpg ]; then
    sudo mkdir -p /etc/apt/keyrings
    curl -fsSL https://packages.microsoft.com/keys/microsoft.asc \
      | gpg --dearmor \
      | sudo tee /etc/apt/keyrings/microsoft.gpg >/dev/null
  fi
  local vscode_repo_line='deb [arch=amd64 signed-by=/etc/apt/keyrings/microsoft.gpg] https://packages.microsoft.com/repos/code stable main'
  if [ -f /etc/apt/sources.list.d/vscode.list ] && grep -qF "$vscode_repo_line" /etc/apt/sources.list.d/vscode.list; then
    step_skip "vscode apt repo" "already configured"
  else
    echo "$vscode_repo_line" | sudo tee /etc/apt/sources.list.d/vscode.list >/dev/null
    step_ok "vscode apt repo"
  fi

  if sudo apt-get update -qq && sudo apt-get install -y -qq \
      vim tmux mosh git curl ca-certificates jq gnupg firefox-esr code >/tmp/apt-install.log 2>&1; then
    step_ok "apt packages"
  else
    step_fail "apt packages" "see /tmp/apt-install.log"
  fi

  if command -v uv >/dev/null 2>&1; then
    step_skip "uv" "already installed"
  else
    if curl -fsSL https://astral.sh/uv/install.sh | sh >/tmp/uv-install.log 2>&1; then
      step_ok "uv"
    else
      step_fail "uv" "see /tmp/uv-install.log"
    fi
  fi

  if code --list-extensions 2>/dev/null | grep -qx "ms-vscode-remote.remote-ssh"; then
    step_skip "vscode remote-ssh extension" "already installed"
  else
    if code --install-extension ms-vscode-remote.remote-ssh >/tmp/vscode-ext.log 2>&1; then
      step_ok "vscode remote-ssh extension"
    else
      step_fail "vscode remote-ssh extension" "see /tmp/vscode-ext.log"
    fi
  fi
}

# ---------- phase 2: tailscale join ----------

tailscale_join() {
  section "tailscale"
  if sudo tailscale status >/dev/null 2>&1; then
    step_skip "tailscale up" "already connected"
  else
    if sudo tailscale up; then
      step_ok "tailscale up"
    else
      step_fail "tailscale up" "tailscale up failed or was not approved"
    fi
  fi
}

# ---------- phase 3: ssh config from tailnet ----------

regen_ssh_config() {
  section "ssh config (tailnet hosts)"
  local sshconf="$HOME/.ssh/config"
  local begin="# BEGIN travel-bootstrap"
  local end="# END travel-bootstrap"

  mkdir -p "$HOME/.ssh"
  chmod 700 "$HOME/.ssh"
  touch "$sshconf"
  chmod 600 "$sshconf"

  local status_json
  if ! status_json=$(tailscale status --json 2>/dev/null); then
    step_fail "ssh config (tailnet hosts)" "tailscale status --json failed"
    return
  fi

  local self_dns suffix user
  self_dns=$(echo "$status_json" | jq -r '.Self.DNSName' | sed 's/\.$//')
  suffix=${self_dns#*.}
  user=$(whoami)

  if [ -z "$suffix" ] || [ "$suffix" = "$self_dns" ]; then
    step_fail "ssh config (tailnet hosts)" "could not determine tailnet suffix from $self_dns"
    return
  fi

  local new_block
  new_block=$(cat <<EOF
$begin
Host *.$suffix
  User $user
  IdentityFile ~/.ssh/id_ed25519_${KEY_NAME}
EOF
)
  while read -r name dns; do
    [ -z "$name" ] && continue
    new_block+=$(cat <<EOF

Host $name
  HostName $dns
  User $user
  IdentityFile ~/.ssh/id_ed25519_${KEY_NAME}
EOF
)
  done < <(echo "$status_json" | jq -r '.Peer[] | "\(.HostName) \(.DNSName | rtrimstr("."))"')
  new_block+=$'\n'"$end"

  local old_block
  old_block=$(awk -v b="$begin" -v e="$end" '$0==b{f=1} f{print} $0==e{f=0}' "$sshconf")

  if [ "$old_block" = "$new_block" ]; then
    step_skip "ssh config (tailnet hosts)" "no change - tailnet peers unchanged"
    return
  fi

  local tmp
  tmp=$(mktemp)
  awk -v b="$begin" -v e="$end" '$0==b{skip=1} !skip{print} $0==e{skip=0}' "$sshconf" > "$tmp"
  printf '%s\n' "$new_block" >> "$tmp"
  mv "$tmp" "$sshconf"
  chmod 600 "$sshconf"

  if [ -z "$old_block" ]; then
    step_ok "ssh config (tailnet hosts)" "wrote wildcard + $(echo "$status_json" | jq '.Peer | length') peer entries"
  else
    step_ok "ssh config (tailnet hosts)" "updated - peer list changed"
  fi
}

# ---------- phase 4: ssh keypair + forgejo registration ----------

forgejo_ssh_key() {
  section "forgejo ssh key"
  local keyfile="$KEYFILE"

  if [ ! -f "$keyfile" ]; then
    ssh-keygen -t ed25519 -f "$keyfile" -N "" -C "${KEY_NAME}-$(date +%Y%m%d)" >/dev/null
  fi

  local pubkey fingerprint
  pubkey=$(cat "${keyfile}.pub")
  fingerprint=$(ssh-keygen -lf "${keyfile}.pub" | awk '{print $2}')

  echo "Need a token: log into $FORGEJO_URL -> avatar (top right) -> Settings ->"
  echo "Applications tab -> Manage Access Tokens -> name it, grant 'write:user'"
  echo "scope (or tick 'user' read+write) -> Generate Token -> copy it now, it's"
  echo "only shown once."
  local token
  read -rsp "Forgejo access token (used once, not stored): " token
  echo

  local tmpbody status
  tmpbody=$(mktemp)
  if ! status=$(curl -sS -o "$tmpbody" -w '%{http_code}' -H "Authorization: token $token" "$FORGEJO_URL/api/v1/user/keys"); then
    step_fail "forgejo ssh key" "GET /api/v1/user/keys - curl could not connect at all (DNS/TLS/network)"
    unset token; rm -f "$tmpbody"
    return
  fi
  if [ "$status" != "200" ]; then
    step_fail "forgejo ssh key" "GET /api/v1/user/keys - HTTP $status: $(cat "$tmpbody") (401=bad token, 403=missing write:user scope, 404=check FORGEJO_URL)"
    unset token; rm -f "$tmpbody"
    return
  fi

  local existing
  existing=$(cat "$tmpbody")
  rm -f "$tmpbody"

  if echo "$existing" | jq -e --arg fp "$fingerprint" '.[] | select(.fingerprint == $fp)' >/dev/null 2>&1; then
    step_skip "forgejo ssh key" "already registered ($fingerprint)"
    unset token
    return
  fi

  local payload
  payload=$(jq -n --arg title "${KEY_NAME}-$(hostname)-$(date +%Y%m%d)" --arg key "$pubkey" \
    '{title: $title, key: $key}')

  tmpbody=$(mktemp)
  if ! status=$(curl -sS -o "$tmpbody" -w '%{http_code}' -X POST \
      -H "Authorization: token $token" \
      -H "Content-Type: application/json" \
      -d "$payload" \
      "$FORGEJO_URL/api/v1/user/keys"); then
    step_fail "forgejo ssh key" "POST /api/v1/user/keys - curl could not connect at all (DNS/TLS/network)"
    unset token; rm -f "$tmpbody"
    return
  fi
  if [ "$status" = "200" ] || [ "$status" = "201" ]; then
    step_ok "forgejo ssh key" "registered ($fingerprint)"
  else
    step_fail "forgejo ssh key" "POST /api/v1/user/keys - HTTP $status: $(cat "$tmpbody") (401=bad token, 403=missing write:user scope, 404=check FORGEJO_URL)"
  fi
  rm -f "$tmpbody"
  unset token
}

# ---------- phase 5: browser hardening ----------

harden_firefox() {
  section "firefox hardening"
  local policy_dir="/etc/firefox/policies"
  local policy_file="$policy_dir/policies.json"

  local desired
  desired=$(cat <<'EOF'
{
  "policies": {
    "DisableTelemetry": true,
    "DisableFirefoxAccounts": true,
    "OfferToSaveLogins": false,
    "NoDefaultBookmarks": true,
    "DisableFormHistory": true,
    "DisablePocket": true,
    "Preferences": {
      "browser.privatebrowsing.autostart": { "Value": true, "Status": "locked" },
      "places.history.enabled": { "Value": false, "Status": "locked" },
      "browser.cache.disk.enable": { "Value": false, "Status": "locked" }
    },
    "ExtensionSettings": {
      "uBlock0@raymondhill.net": {
        "installation_mode": "force_installed",
        "install_url": "https://addons.mozilla.org/firefox/downloads/latest/ublock-origin/latest.xpi"
      }
    }
  }
}
EOF
)

  if [ -f "$policy_file" ] && [ "$(cat "$policy_file")" = "$desired" ]; then
    step_skip "firefox policy" "already up to date"
    return
  fi

  sudo mkdir -p "$policy_dir"
  echo "$desired" | sudo tee "$policy_file" >/dev/null
  step_ok "firefox policy" "wrote $policy_file - VERIFY: private-browsing-autostart + forced uBlock Origin behave as expected on first launch"
}

main() {
  preflight_env
  gather_config
  preflight_connectivity
  install_packages
  tailscale_join
  regen_ssh_config
  forgejo_ssh_key
  harden_firefox
  print_summary
}

if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
  main "$@"
fi