#!/usr/bin/env bash
#
# Build and install the furst toolset. Safe to re-run: it never overwrites a
# config you have edited, and every system-changing step can be skipped.
#
#   ./install.sh --help

set -euo pipefail

PREFIX="${HOME}/.local/bin"
CONFIG_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/furst"
CACHE_DIR="${XDG_CACHE_HOME:-$HOME/.cache}/furst"
UNIT_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/systemd/user"
DESKTOP="${XDG_DATA_HOME:-$HOME/.local/share}/applications/furst.desktop"

BINARIES=(furst furst-read furst-serve furst-proxy)
HANDLERS=(mpv yt-dlp zathura nsxiv surf firefox)

MODE=install
DO_BUILD=1
DO_LISTS=1
DO_SERVICE=1
DO_BROWSER=ask
PURGE=0

if [ -t 1 ]; then
  B=$'\033[1m'; DIM=$'\033[2m'; GREEN=$'\033[32m'; YELLOW=$'\033[33m'; RED=$'\033[31m'; R=$'\033[0m'
else
  B=; DIM=; GREEN=; YELLOW=; RED=; R=
fi

step() { printf '\n%s==>%s %s%s%s\n' "$GREEN" "$R" "$B" "$1" "$R"; }
info() { printf '    %s\n' "$1"; }
skip() { printf '    %s%s%s\n' "$DIM" "$1" "$R"; }
warn() { printf '    %s!%s %s\n' "$YELLOW" "$R" "$1"; }
die()  { printf '\n%serror:%s %s\n' "$RED" "$R" "$1" >&2; exit 1; }

usage() {
  cat <<'EOF'
install.sh — build and install the furst toolset

USAGE
    ./install.sh [OPTIONS]

OPTIONS
    --prefix <dir>          where to install binaries (default ~/.local/bin)
    --no-build              install from an existing target/release build
    --no-lists              skip downloading the proxy blocklists
    --no-service            skip the systemd user service for the proxy
    --no-default-browser    do not register furst as the default browser
    -y, --yes               answer every prompt with yes
    --uninstall             remove binaries, service and desktop entry
    --purge                 with --uninstall, also remove configs and caches
    -h, --help              this

The install never overwrites an existing config file, so re-running it after
editing your rules is safe.
EOF
}

while [ $# -gt 0 ]; do
  case "$1" in
    --prefix)             PREFIX="${2:?--prefix needs a directory}"; shift 2 ;;
    --no-build)           DO_BUILD=0; shift ;;
    --no-lists)           DO_LISTS=0; shift ;;
    --no-service)         DO_SERVICE=0; shift ;;
    --no-default-browser) DO_BROWSER=no; shift ;;
    -y|--yes)             DO_BROWSER=yes; shift ;;
    --uninstall)          MODE=uninstall; shift ;;
    --purge)              PURGE=1; shift ;;
    -h|--help)            usage; exit 0 ;;
    *) die "unknown option $1 (--help for usage)" ;;
  esac
done

# ---------------------------------------------------------------- uninstall ---

if [ "$MODE" = uninstall ]; then
  step "Removing the service"
  if command -v systemctl >/dev/null 2>&1; then
    systemctl --user disable --now furst-proxy.service 2>/dev/null || true
    rm -f "$UNIT_DIR/furst-proxy.service" "$UNIT_DIR/furst-serve.service"
    systemctl --user daemon-reload 2>/dev/null || true
    info "stopped and removed"
  else
    skip "no systemctl"
  fi

  step "Removing binaries"
  for b in "${BINARIES[@]}"; do
    if [ -e "$PREFIX/$b" ]; then rm -f "$PREFIX/$b"; info "removed $PREFIX/$b"; fi
  done

  step "Removing the desktop entry"
  rm -f "$DESKTOP"
  info "removed $DESKTOP"
  warn "your default browser is now unset — pick one in your desktop settings,"
  warn "or run: xdg-settings set default-web-browser firefox.desktop"

  if [ "$PURGE" = 1 ]; then
    step "Purging configs and caches"
    rm -rf "$CONFIG_DIR" "$CACHE_DIR" "${XDG_CACHE_HOME:-$HOME/.cache}/furst-read"
    info "removed $CONFIG_DIR and caches"
  else
    step "Kept"
    info "$CONFIG_DIR and caches — remove with --uninstall --purge"
  fi
  printf '\n%sUninstalled.%s\n\n' "$B" "$R"
  exit 0
fi

# ------------------------------------------------------------------- build ---

cd "$(dirname "$0")"

if [ "$DO_BUILD" = 1 ]; then
  step "Building"
  command -v cargo >/dev/null 2>&1 || die "cargo not found — install rust first"
  info "$(cargo --version)"
  # --workspace matters: the root package is only furst, so a bare build would
  # silently skip the other three.
  cargo build --release --workspace
  info "built 4 binaries"
else
  step "Skipping build"
fi

for b in "${BINARIES[@]}"; do
  [ -x "target/release/$b" ] || die "target/release/$b missing — run without --no-build"
done

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

step "Installing to $PREFIX"
mkdir -p "$PREFIX"
for b in "${BINARIES[@]}"; do
  install -m755 "target/release/$b" "$PREFIX/$b"
  info "$b  $(du -h "$PREFIX/$b" | cut -f1)"
done

case ":$PATH:" in
  *":$PREFIX:"*) ;;
  *) warn "$PREFIX is not on your \$PATH — add this to ~/.zshrc:"
     warn "  export PATH=\"$PREFIX:\$PATH\"" ;;
esac

export PATH="$PREFIX:$PATH"

# ----------------------------------------------------------------- configs ---

step "Writing starter configs"
mkdir -p "$CONFIG_DIR"
init_config() {
  local file="$1" cmd="$2"
  if [ -e "$CONFIG_DIR/$file" ]; then
    skip "$file already exists, left alone"
  else
    "$PREFIX/$cmd" --init >/dev/null && info "$file"
  fi
}
init_config rules.toml furst
init_config home.toml  furst-serve
init_config proxy.toml furst-proxy

# ---------------------------------------------------------------- handlers ---

step "Checking handlers"
missing=()
for h in "${HANDLERS[@]}"; do
  command -v "$h" >/dev/null 2>&1 || missing+=("$h")
done
if [ ${#missing[@]} -eq 0 ]; then
  info "all present"
else
  warn "not installed: ${missing[*]}"
  warn "rules naming them fall through to the next handler; install with:"
  warn "  sudo pacman -S mpv yt-dlp zathura zathura-pdf-mupdf nsxiv surf"
fi

# --------------------------------------------------------------- blocklists ---

if [ "$DO_LISTS" = 1 ]; then
  step "Fetching blocklists"
  if "$PREFIX/furst-proxy" --update 2>&1 | sed 's/^/    /'; then :; else
    warn "could not fetch — the proxy will run with only its built-in rules"
  fi
else
  step "Skipping blocklists"
  skip "run 'furst-proxy --update' later"
fi

# ------------------------------------------------------------------ service ---

if [ "$DO_SERVICE" = 1 ] && command -v systemctl >/dev/null 2>&1; then
  step "Installing the proxy service"
  mkdir -p "$UNIT_DIR"
  cat > "$UNIT_DIR/furst-proxy.service" <<EOF
[Unit]
Description=furst filtering proxy
After=network-online.target

[Service]
ExecStart=$PREFIX/furst-proxy
Restart=on-failure
RestartSec=5

[Install]
WantedBy=default.target
EOF
  # The reader starts itself on demand, so this one is offered, not enabled.
  cat > "$UNIT_DIR/furst-serve.service" <<EOF
[Unit]
Description=furst reader server (optional; it also starts on demand)

[Service]
ExecStart=$PREFIX/furst-serve
Restart=on-failure
RestartSec=5

[Install]
WantedBy=default.target
EOF
  systemctl --user daemon-reload 2>/dev/null || true
  if systemctl --user enable --now furst-proxy.service 2>/dev/null; then
    info "furst-proxy.service enabled and started"
  else
    warn "could not start the service — run it yourself with: furst-proxy &"
  fi
  skip "furst-serve.service written but not enabled (the reader autostarts)"
else
  step "Skipping the service"
  skip "start the proxy yourself: furst-proxy &"
fi

# ---------------------------------------------------------- default browser ---

step "Default browser"
if [ "$DO_BROWSER" = ask ]; then
  if [ -t 0 ]; then
    printf '    Register furst as your default browser? [y/N] '
    read -r reply
    case "$reply" in [yY]*) DO_BROWSER=yes ;; *) DO_BROWSER=no ;; esac
  else
    DO_BROWSER=no
  fi
fi

if [ "$DO_BROWSER" = yes ]; then
  "$PREFIX/furst" --install 2>&1 | sed 's/^/    /'
else
  skip "not changed — run 'furst --install' when you want it"
fi

# -------------------------------------------------------------------- done ---

cat <<EOF

${B}Installed.${R}

  Add to ~/.zshrc so everything uses the proxy:
      eval "\$(furst-proxy --env)"

  Firefox needs it set manually: Settings > Network Settings > Manual,
  127.0.0.1 port 8228, and tick "Also use this proxy for HTTPS".

  Reader home   http://127.0.0.1:7714/
  Proxy status  http://furst.proxy/

  Read ${B}GUIDE.md${R} next. The command to remember is:
      furst --explain <url>

EOF