#!/usr/bin/env bash
# Local development setup for gc_index_relay.
# Safe to run multiple times — all steps are idempotent.
#
# Requirements:
#   - Docker must already be installed (https://docs.docker.com/engine/install/)
#   - sudo access for apt-get
#
# Usage:
#   chmod +x setup.sh
#   ./setup.sh

set -euo pipefail

# ---------------------------------------------------------------------------
# Configuration
# ---------------------------------------------------------------------------

ERLANG_VERSION="28.4.1"
ELIXIR_VERSION="1.19.5-otp-28"

POSTGRES_HOST="localhost"
POSTGRES_PORT="5455"
POSTGRES_USER="postgres"
POSTGRES_PASSWORD="postgres"
POSTGRES_DB="gc_index_relay_dev"

DOCKER_CONTAINER_NAME="gc_age_db"
AGE_IMAGE="apache/age:release_PG17_1.6.0"

ASDF_DIR="$HOME/.asdf"
ASDF_VERSION="v0.15.0"

PROJECT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

GREEN='\033[0;32m'
YELLOW='\033[1;33m'
RED='\033[0;31m'
NC='\033[0m'

log()  { echo -e "${GREEN}[setup]${NC} $*"; }
warn() { echo -e "${YELLOW}[ warn]${NC} $*"; }
err()  { echo -e "${RED}[error]${NC} $*" >&2; exit 1; }

require_cmd() {
  command -v "$1" &>/dev/null || err "'$1' is not installed or not on PATH. $2"
}

# ---------------------------------------------------------------------------
# 1. Pre-flight checks
# ---------------------------------------------------------------------------

log "Starting gc_index_relay local setup..."
echo

require_cmd docker "Install Docker first: https://docs.docker.com/engine/install/"
docker info &>/dev/null || err "Docker daemon is not running. Start it and try again."
log "Docker: $(docker --version)"

# ---------------------------------------------------------------------------
# 2. System build dependencies (Debian/Ubuntu/Mint)
# ---------------------------------------------------------------------------

if command -v apt-get &>/dev/null; then
  log "Installing system build dependencies via apt-get..."
  sudo apt-get update -qq
  sudo apt-get install -y \
    build-essential \
    autoconf \
    libtool \
    inotify-tools \
    git \
    curl
else
  warn "apt-get not found — skipping system package install."
  warn "Make sure these are installed manually: build-essential autoconf libtool inotify-tools git curl"
fi

# ---------------------------------------------------------------------------
# 3. asdf version manager
# ---------------------------------------------------------------------------

if [ ! -d "$ASDF_DIR" ]; then
  log "Installing asdf $ASDF_VERSION..."
  git clone https://github.com/asdf-vm/asdf.git "$ASDF_DIR" --branch "$ASDF_VERSION"
else
  log "asdf already installed at $ASDF_DIR"
fi

# Source asdf for this script session
# shellcheck source=/dev/null
source "$ASDF_DIR/asdf.sh"

# Persist asdf sourcing to the user's shell rc (idempotent)
add_asdf_to_rc() {
  local rc="$1"
  local line='. "$HOME/.asdf/asdf.sh"'
  if [ -f "$rc" ] && ! grep -qF 'asdf/asdf.sh' "$rc"; then
    echo "" >> "$rc"
    echo "# asdf version manager" >> "$rc"
    echo "$line" >> "$rc"
    log "Added asdf to $rc (will take effect in new shells)"
  fi
}
add_asdf_to_rc "$HOME/.bashrc"
add_asdf_to_rc "$HOME/.zshrc" 2>/dev/null || true

# ---------------------------------------------------------------------------
# 4. Erlang
# ---------------------------------------------------------------------------

asdf plugin add erlang 2>/dev/null || true

if asdf list erlang 2>/dev/null | grep -qF "$ERLANG_VERSION"; then
  log "Erlang $ERLANG_VERSION already installed"
else
  log "Installing Erlang $ERLANG_VERSION (compiles from source — takes a few minutes)..."
  asdf install erlang "$ERLANG_VERSION"
fi

asdf global erlang "$ERLANG_VERSION"

# ---------------------------------------------------------------------------
# 5. Elixir
# ---------------------------------------------------------------------------

asdf plugin add elixir 2>/dev/null || true

if asdf list elixir 2>/dev/null | grep -qF "$ELIXIR_VERSION"; then
  log "Elixir $ELIXIR_VERSION already installed"
else
  log "Installing Elixir $ELIXIR_VERSION..."
  asdf install elixir "$ELIXIR_VERSION"
fi

asdf global elixir "$ELIXIR_VERSION"
log "$(elixir --version | grep 'Elixir')"

# ---------------------------------------------------------------------------
# 6. Apache AGE database (Docker)
# ---------------------------------------------------------------------------

if docker ps -q --filter "name=^${DOCKER_CONTAINER_NAME}$" | grep -q .; then
  log "Database container '$DOCKER_CONTAINER_NAME' is already running"
elif docker ps -aq --filter "name=^${DOCKER_CONTAINER_NAME}$" | grep -q .; then
  log "Restarting existing database container '$DOCKER_CONTAINER_NAME'..."
  docker start "$DOCKER_CONTAINER_NAME"
else
  log "Starting Apache AGE database container..."
  docker run -d \
    --name "$DOCKER_CONTAINER_NAME" \
    -p "${POSTGRES_PORT}:5432" \
    -e POSTGRES_USER="$POSTGRES_USER" \
    -e POSTGRES_PASSWORD="$POSTGRES_PASSWORD" \
    -e POSTGRES_DB="$POSTGRES_DB" \
    "$AGE_IMAGE"
fi

log "Waiting for database to accept connections..."
until docker exec "$DOCKER_CONTAINER_NAME" pg_isready -U "$POSTGRES_USER" &>/dev/null; do
  sleep 1
done
log "Database is ready"

# ---------------------------------------------------------------------------
# 7. .env file
# ---------------------------------------------------------------------------

ENV_FILE="$PROJECT_DIR/.env"

if [ ! -f "$ENV_FILE" ]; then
  log "Writing .env with database credentials..."
  cat > "$ENV_FILE" <<EOF
export POSTGRES_HOST=$POSTGRES_HOST
export POSTGRES_PORT=$POSTGRES_PORT
export POSTGRES_USER=$POSTGRES_USER
export POSTGRES_PASSWORD=$POSTGRES_PASSWORD
export POSTGRES_DB=$POSTGRES_DB
EOF
else
  log ".env already exists — skipping (delete it to regenerate)"
fi

# Export for the current session so mix setup can connect
export POSTGRES_HOST POSTGRES_PORT POSTGRES_USER POSTGRES_PASSWORD POSTGRES_DB

# ---------------------------------------------------------------------------
# 8. Mix setup (deps + database)
# ---------------------------------------------------------------------------

cd "$PROJECT_DIR"

log "Installing Hex and Rebar (if needed)..."
mix local.hex --force --if-missing
mix local.rebar --force --if-missing

log "Fetching dependencies..."
mix deps.get

log "Running mix setup (compile + create DB + migrate)..."
mix setup

# ---------------------------------------------------------------------------
# Done
# ---------------------------------------------------------------------------

echo
log "Setup complete!"
echo
echo "  To start the server:"
echo "    source .env"
echo "    mix phx.server"
echo
echo "  Then open: http://localhost:4000"
echo "  REST API:  http://localhost:4000/api/events"
echo
warn "Open a new terminal (or run 'source ~/.bashrc') for asdf to work in future sessions."