#!/usr/bin/env bash
# install.sh — set up the agent-watcher Collector on this machine.
#
# Usage:
#   ./install.sh                  # build + install + enable + start
#   ./install.sh --no-start       # everything but `systemctl start`
#
# What it does:
#   1. Builds the agent-watcher binary (requires Go 1.22+).
#   2. Installs to ~/.local/bin/agent-watcher.
#   3. Drops the systemd --user unit into ~/.config/systemd/user/.
#   4. Drops a starter ~/.config/agent-watcher/collector.yaml if missing
#      (copies examples/collector.yaml; you edit it before first start).
#   5. Reloads systemd, enables, and (unless --no-start) starts the unit.
#   6. Adds drop-folder lifecycle patterns to the workspace .stignore so
#      drop files do not Syncthing-replicate during local processing.
#
# Per CLAUDE.md rule #2, this is intended to be run by a human. The
# Collector itself, like agent-ping, never invokes this script.
#
# Layer 2 (MCP Watcher) has its own install path — different language,
# different runtime, different unit. See its README when it lands.

set -euo pipefail

NO_START=0
for arg in "$@"; do
    case "$arg" in
        --no-start) NO_START=1 ;;
        *) echo "unknown arg: $arg" >&2; exit 2 ;;
    esac
done

REPO_DIR="$(cd "$(dirname "$0")" && pwd)"
BIN_DIR="$HOME/.local/bin"
CONF_DIR="$HOME/.config/agent-watcher"
UNIT_DIR="$HOME/.config/systemd/user"
WORKSPACE="$HOME/Nyx/workspace"
STIGNORE="$WORKSPACE/.stignore"

echo "agent-watcher install"
echo "repo: $REPO_DIR"
echo

# 1. Check Go
echo "[1/6] checking Go toolchain"
if ! command -v go >/dev/null 2>&1; then
    echo "  ERROR: 'go' not found. Install Go 1.22+ first." >&2
    echo "  e.g. sudo apt install golang-go" >&2
    exit 1
fi
GO_VERSION=$(go version | awk '{print $3}')
echo "  $GO_VERSION"

# 2. Build
echo "[2/6] building agent-watcher binary"
mkdir -p "$BIN_DIR"
( cd "$REPO_DIR" && go build -o "$BIN_DIR/agent-watcher" ./cmd/agent-watcher )
echo "  installed: $BIN_DIR/agent-watcher"

# 3. systemd unit
echo "[3/6] installing systemd --user unit"
mkdir -p "$UNIT_DIR"
install -m 0644 "$REPO_DIR/systemd/agent-watcher.service" "$UNIT_DIR/agent-watcher.service"
echo "  installed: $UNIT_DIR/agent-watcher.service"

# 4. Config skeleton
echo "[4/6] config skeleton"
mkdir -p "$CONF_DIR"
if [ -f "$CONF_DIR/collector.yaml" ]; then
    echo "  $CONF_DIR/collector.yaml exists — leaving as-is"
else
    install -m 0644 "$REPO_DIR/examples/collector.yaml" "$CONF_DIR/collector.yaml"
    echo "  installed example: $CONF_DIR/collector.yaml — EDIT BEFORE START"
fi

# 5. .stignore — drop folder is replicated, but lifecycle artifacts shouldn't be
echo "[5/6] .stignore (drop-folder lifecycle artifacts are local-only)"
if [ -d "$WORKSPACE" ]; then
    touch "$STIGNORE"
    for pattern in "incoming/.dead-letter/" "incoming/*.json.tmp"; do
        if ! grep -qxF "$pattern" "$STIGNORE"; then
            echo "$pattern" >> "$STIGNORE"
            echo "  added: $pattern"
        fi
    done
else
    echo "  $WORKSPACE not present — skipping (Syncthing not set up here)"
fi

# 6. systemd reload + enable + (optionally) start
echo "[6/6] systemd reload + enable"
systemctl --user daemon-reload
systemctl --user enable agent-watcher.service >/dev/null
echo "  enabled at user login (loginctl enable-linger required to run when logged out)"

if [ "$NO_START" -eq 0 ]; then
    echo "  starting…"
    systemctl --user restart agent-watcher.service
    sleep 1
    systemctl --user status agent-watcher.service --no-pager -n 5 || true
else
    echo "  --no-start: not starting; run 'systemctl --user start agent-watcher' when ready"
fi

echo
echo "installation complete."
echo
echo "next steps:"
echo "  1. EDIT $CONF_DIR/collector.yaml to suit this host."
echo "  2. systemctl --user restart agent-watcher (after edits)."
echo "  3. journalctl --user -u agent-watcher -f  (watch logs)."
echo "  4. curl http://127.0.0.1:18790/health      (sanity check)."
echo "  5. To survive logout: loginctl enable-linger \$USER"