#!/usr/bin/env bash
# Install farm on macOS or Linux:
#
#   curl -fsSL https://farm.kylesoft.com/install.sh | bash
#
# Puts farm in ~/buildfarm (or --dir / $FARM_HOME) and a `farm` command in ~/.local/bin.
# No sudo, nothing outside those two places (plus one PATH line in your shell profile if
# ~/.local/bin isn't on your PATH yet). Running it again updates farm and keeps your
# machines, builds and settings.
set -euo pipefail

VERSION="0.2.0"
SHA256="303d6181bf955b987665fa53ccc8f8cff3de19cd6a4e8371552f4bda2a320928"
SITE="${FARM_SITE:-https://farm.kylesoft.com}"
# Where release files live (this site today; maybe a storage bucket later).
DOWNLOADS="${FARM_DOWNLOADS:-${FARM_SITE:-https://farm.kylesoft.com}}"
DIR="${FARM_HOME:-$HOME/buildfarm}"
SETUP=ask
while [ $# -gt 0 ]; do
  case "$1" in
    --dir) DIR="$2"; shift 2 ;;
    --no-setup) SETUP=no; shift ;;
    --setup) SETUP=yes; shift ;;
    -h|--help) echo "usage: install.sh [--dir DIR] [--setup|--no-setup]"; exit 0 ;;
    *) echo "install.sh: unknown option $1" >&2; exit 2 ;;
  esac
done

say()  { printf '\033[1m==>\033[0m %s\n' "$*"; }
note() { printf '    %s\n' "$*"; }
die()  { printf 'install.sh: %s\n' "$*" >&2; exit 1; }

OS="$(uname -s)"
[ "$OS" = Linux ] || [ "$OS" = Darwin ] || die "this installer is for macOS and Linux; on Windows use install.ps1"
[ "$(id -u)" != 0 ] || die "install farm as your normal user, not root"

# ------------------------------------------------------------------ what farm needs

missing=()
py=""
for c in python3 python; do
  if command -v "$c" >/dev/null && "$c" -c 'import sys; sys.exit(sys.version_info < (3, 8))' 2>/dev/null; then py="$c"; break; fi
done
[ -n "$py" ] || missing+=(python3)
command -v git >/dev/null || missing+=(git)
command -v ssh >/dev/null || missing+=(ssh)
if [ ${#missing[@]} -gt 0 ]; then
  echo "farm needs: ${missing[*]}" >&2
  if [ "$OS" = Darwin ]; then
    echo "Install Apple's command line tools (they include all three), then run this again:" >&2
    echo "  xcode-select --install" >&2
  else
    echo "Install them with your package manager, then run this again. For example:" >&2
    echo "  sudo apt install python3 git openssh-client     # Debian, Ubuntu" >&2
    echo "  sudo dnf install python3 git openssh-clients    # Fedora" >&2
    echo "  sudo pacman -S python git openssh               # Arch" >&2
  fi
  exit 1
fi

if [ -d "$DIR/.git" ]; then
  die "$DIR is a git checkout of farm; update it with git pull instead"
fi

# ------------------------------------------------------------------ download and check

tmp="$(mktemp -d)"
trap 'rm -rf "$tmp"' EXIT
tarball="farm-$VERSION.tar.gz"
say "Downloading farm $VERSION"
curl -fsSL --proto '=https' --tlsv1.2 -o "$tmp/$tarball" "$DOWNLOADS/$tarball"
if command -v sha256sum >/dev/null; then got="$(sha256sum "$tmp/$tarball" | awk '{print $1}')"
else got="$(shasum -a 256 "$tmp/$tarball" | awk '{print $1}')"; fi
[ "$got" = "$SHA256" ] || die "the download doesn't match its checksum (got $got). Nothing was installed."
note "checksum ok"

mkdir -p "$tmp/x"
tar -xzf "$tmp/$tarball" -C "$tmp/x"
src="$tmp/x/farm-$VERSION"
[ -x "$src/bin/farm" ] || die "unexpected archive layout"

# ------------------------------------------------------------------ install

say "Installing into $DIR"
mkdir -p "$DIR"
# Replace farm's own files; hosts.toml, state/, artifacts/ and work/ are yours and stay.
for d in bin lib bootstrap templates join; do rm -rf "${DIR:?}/$d"; cp -R "$src/$d" "$DIR/$d"; done
cp "$src/README.md" "$src/hosts.example.toml" "$DIR/"
[ -f "$src/LICENSE" ] && cp "$src/LICENSE" "$DIR/"
chmod +x "$DIR/bin/farm"
# Use the Python we found, whatever it's called here.
if [ "$py" != python3 ]; then sed -i.bak "1s|.*|#!/usr/bin/env $py|" "$DIR/bin/farm" && rm -f "$DIR/bin/farm.bak"; fi

mkdir -p "$HOME/.local/bin"
ln -sf "$DIR/bin/farm" "$HOME/.local/bin/farm"
note "farm command: ~/.local/bin/farm"

case ":$PATH:" in
  *":$HOME/.local/bin:"*) ;;
  *)
    if [ "$OS" = Darwin ] || [ "${SHELL##*/}" = zsh ]; then rc="$HOME/.zshrc"; else rc="$HOME/.bashrc"; fi
    [ "${SHELL##*/}" = fish ] && rc=""
    if [ -n "$rc" ] && ! grep -qs 'added by farm' "$rc"; then
      # shellcheck disable=SC2016  # written literally, expanded by the shell later
      printf '\nexport PATH="$HOME/.local/bin:$PATH"  # added by farm\n' >> "$rc"
      note "added ~/.local/bin to your PATH in $rc (open a new terminal for it to apply)"
    else
      note "add ~/.local/bin to your PATH to run farm by name"
    fi
    ;;
esac

"$DIR/bin/farm" version >/dev/null || die "farm was copied but doesn't start; please report this"
echo
say "farm $VERSION is installed."

if [ "$SETUP" = ask ] && [ -r /dev/tty ] && [ -t 1 ]; then
  read -r -p "Set it up now (check this computer, add a build machine)? [Y/n] " a < /dev/tty || a=n
  case "$a" in n*|N*) SETUP=no ;; *) SETUP=yes ;; esac
fi
if [ "$SETUP" = yes ]; then
  "$DIR/bin/farm" setup < /dev/tty
else
  echo
  echo "Next:"
  echo "  farm setup     check this computer and add a build machine"
  echo "  farm ui        or do everything from your browser"
fi