#!/usr/bin/env bash
# scripts/common.sh — Shared bash library for HomeAI setup scripts
# Source this file: source "$(dirname "$0")/../scripts/common.sh"
# Do NOT execute directly.

set -euo pipefail

# ─── Colours ───────────────────────────────────────────────────────────────────
if [[ -t 1 ]]; then
  RED='\033[0;31m'; YELLOW='\033[0;33m'; GREEN='\033[0;32m'
  BLUE='\033[0;34m'; CYAN='\033[0;36m'; BOLD='\033[1m'; RESET='\033[0m'
else
  RED=''; YELLOW=''; GREEN=''; BLUE=''; CYAN=''; BOLD=''; RESET=''
fi

# ─── Logging ───────────────────────────────────────────────────────────────────
log_info()    { echo -e "${BLUE}[INFO]${RESET}  $*"; }
log_success() { echo -e "${GREEN}[OK]${RESET}    $*"; }
log_warn()    { echo -e "${YELLOW}[WARN]${RESET}  $*"; }
log_error()   { echo -e "${RED}[ERROR]${RESET} $*" >&2; }
log_section() { echo -e "\n${BOLD}${CYAN}══ $* ══${RESET}"; }
log_step()    { echo -e "${CYAN}  →${RESET} $*"; }

die() { log_error "$*"; exit 1; }

# ─── OS & Architecture Detection ───────────────────────────────────────────────
detect_os() {
  case "$(uname -s)" in
    Linux*)  OS_TYPE=linux  ;;
    Darwin*) OS_TYPE=macos  ;;
    *)       die "Unsupported OS: $(uname -s)" ;;
  esac
  export OS_TYPE
}

detect_arch() {
  case "$(uname -m)" in
    x86_64|amd64) ARCH=amd64   ;;
    arm64|aarch64) ARCH=arm64  ;;
    *)             ARCH=unknown ;;
  esac
  export ARCH
}

detect_distro() {
  DISTRO=unknown
  if [[ "$OS_TYPE" == "linux" ]]; then
    if [[ -f /etc/os-release ]]; then
      # shellcheck disable=SC1091
      source /etc/os-release
      DISTRO="${ID:-unknown}"
    fi
  fi
  export DISTRO
}

detect_platform() {
  detect_os
  detect_arch
  detect_distro
  log_info "Platform: ${OS_TYPE}/${ARCH} (${DISTRO})"
}

# ─── GPU Detection ─────────────────────────────────────────────────────────────
detect_gpu() {
  GPU_TYPE=none
  if [[ "$OS_TYPE" == "macos" && "$ARCH" == "arm64" ]]; then
    GPU_TYPE=metal
  elif command -v nvidia-smi &>/dev/null && nvidia-smi &>/dev/null; then
    GPU_TYPE=cuda
    GPU_INFO=$(nvidia-smi --query-gpu=name --format=csv,noheader 2>/dev/null | head -1 || true)
  elif command -v rocm-smi &>/dev/null; then
    GPU_TYPE=rocm
    GPU_INFO=$(rocm-smi --showproductname 2>/dev/null | head -1 || true)
  fi
  export GPU_TYPE GPU_INFO
  log_info "GPU: ${GPU_TYPE}${GPU_INFO:+ — ${GPU_INFO}}"
}

# ─── Dependency Checking ───────────────────────────────────────────────────────
require_command() {
  local cmd="$1"
  local hint="${2:-install $cmd}"
  if ! command -v "$cmd" &>/dev/null; then
    die "'$cmd' is required but not found. Hint: $hint"
  fi
}

command_exists() { command -v "$1" &>/dev/null; }

require_min_version() {
  local cmd="$1" required="$2"
  local actual
  actual="$("$cmd" --version 2>&1 | grep -oE '[0-9]+\.[0-9]+(\.[0-9]+)?' | head -1)"
  if [[ "$(printf '%s\n' "$required" "$actual" | sort -V | head -1)" != "$required" ]]; then
    die "$cmd version $required+ required, found $actual"
  fi
}

# ─── Package Management ────────────────────────────────────────────────────────
install_package() {
  local pkg="$1"
  log_step "Installing $pkg..."
  case "$OS_TYPE" in
    linux)
      case "$DISTRO" in
        ubuntu|debian|linuxmint|pop)
          sudo apt-get install -y -qq "$pkg" ;;
        fedora|rhel|centos|rocky|almalinux)
          sudo dnf install -y -q "$pkg" ;;
        arch|manjaro|endeavouros)
          sudo pacman -S --noconfirm --quiet "$pkg" ;;
        opensuse*)
          sudo zypper install -y -q "$pkg" ;;
        *)
          die "Unknown distro '$DISTRO' — install $pkg manually" ;;
      esac ;;
    macos)
      if ! command_exists brew; then
        die "Homebrew not found. Install from https://brew.sh"
      fi
      brew install "$pkg" ;;
  esac
}

update_package_index() {
  if [[ "$OS_TYPE" == "linux" ]]; then
    case "$DISTRO" in
      ubuntu|debian|linuxmint|pop) sudo apt-get update -qq ;;
      fedora|rhel|centos|rocky|almalinux) sudo dnf check-update -q || true ;;
    esac
  fi
}

# ─── Docker ────────────────────────────────────────────────────────────────────
check_docker_installed() {
  command_exists docker
}

check_docker_running() {
  docker info &>/dev/null
}

install_docker() {
  if check_docker_installed; then
    log_success "Docker already installed: $(docker --version)"
    return
  fi

  log_info "Installing Docker..."

  if [[ "$OS_TYPE" == "macos" ]]; then
    die "On macOS, install Docker Desktop manually: https://www.docker.com/products/docker-desktop/"
  fi

  # Linux: use the official convenience script
  curl -fsSL https://get.docker.com -o /tmp/get-docker.sh
  sudo sh /tmp/get-docker.sh
  rm /tmp/get-docker.sh

  # Add current user to docker group
  sudo usermod -aG docker "$USER"
  log_warn "Added $USER to docker group. Log out and back in (or run 'newgrp docker') for it to take effect."

  # Start and enable Docker
  sudo systemctl enable --now docker
  log_success "Docker installed: $(docker --version)"
}

ensure_docker_running() {
  if ! check_docker_running; then
    if [[ "$OS_TYPE" == "linux" ]]; then
      log_info "Starting Docker..."
      sudo systemctl start docker
      sleep 2
    else
      die "Docker Desktop is not running. Start it from your Applications folder."
    fi
  fi
  if ! check_docker_running; then
    die "Docker is not running. Start Docker and retry."
  fi
}

ensure_docker_network() {
  local network="${1:-homeai}"
  if ! docker network inspect "$network" &>/dev/null; then
    log_step "Creating Docker network '$network'..."
    docker network create "$network"
    log_success "Network '$network' created."
  else
    log_info "Docker network '$network' already exists."
  fi
}

# ─── Docker Compose ────────────────────────────────────────────────────────────
# Handles both `docker compose` (v2) and `docker-compose` (v1)
docker_compose() {
  if docker compose version &>/dev/null 2>&1; then
    docker compose "$@"
  elif command_exists docker-compose; then
    docker-compose "$@"
  else
    die "docker compose not found. Ensure Docker is up to date."
  fi
}

# ─── Service Management ────────────────────────────────────────────────────────
install_service() {
  # Usage: install_service <name> <systemd_unit_file> <launchd_plist_file>
  local name="$1"
  local systemd_file="$2"
  local launchd_file="$3"

  if [[ "$OS_TYPE" == "linux" ]]; then
    if [[ ! -f "$systemd_file" ]]; then
      log_warn "No systemd unit file at $systemd_file — skipping service install."
      return
    fi
    log_step "Installing systemd service: $name"
    sudo cp "$systemd_file" "/etc/systemd/system/${name}.service"
    sudo systemctl daemon-reload
    sudo systemctl enable --now "$name"
    log_success "Service '$name' enabled and started."

  elif [[ "$OS_TYPE" == "macos" ]]; then
    if [[ ! -f "$launchd_file" ]]; then
      log_warn "No launchd plist at $launchd_file — skipping service install."
      return
    fi
    local plist_dest="${HOME}/Library/LaunchAgents/$(basename "$launchd_file")"
    log_step "Installing launchd agent: $name"
    cp "$launchd_file" "$plist_dest"
    launchctl load -w "$plist_dest"
    log_success "LaunchAgent '$name' installed and loaded."
  fi
}

uninstall_service() {
  local name="$1"
  local plist_label="${2:-$name}"

  if [[ "$OS_TYPE" == "linux" ]]; then
    sudo systemctl disable --now "$name" 2>/dev/null || true
    sudo rm -f "/etc/systemd/system/${name}.service"
    sudo systemctl daemon-reload
  elif [[ "$OS_TYPE" == "macos" ]]; then
    local plist_path="${HOME}/Library/LaunchAgents/${plist_label}.plist"
    launchctl unload -w "$plist_path" 2>/dev/null || true
    rm -f "$plist_path"
  fi
}

# ─── Environment Files ─────────────────────────────────────────────────────────
load_env() {
  local env_file="${1:-.env}"
  if [[ -f "$env_file" ]]; then
    # shellcheck disable=SC1090
    set -a; source "$env_file"; set +a
  fi
}

load_env_services() {
  local services_file="${HOME}/.env.services"
  if [[ -f "$services_file" ]]; then
    set -a; source "$services_file"; set +a
  fi
}

write_env_service() {
  # Append or update KEY=VALUE in ~/.env.services
  local key="$1" value="$2"
  local file="${HOME}/.env.services"
  touch "$file"
  if grep -q "^${key}=" "$file" 2>/dev/null; then
    # Update existing
    sed -i "s|^${key}=.*|${key}=${value}|" "$file"
  else
    echo "${key}=${value}" >> "$file"
  fi
}

# Bootstrap .env from .env.example if not present
bootstrap_env() {
  local dir="${1:-.}"
  if [[ ! -f "${dir}/.env" && -f "${dir}/.env.example" ]]; then
    cp "${dir}/.env.example" "${dir}/.env"
    log_warn "Created ${dir}/.env from .env.example — fill in secrets before continuing."
  fi
}

# ─── Network Helpers ───────────────────────────────────────────────────────────
wait_for_http() {
  local url="$1" name="${2:-service}" timeout="${3:-60}"
  log_step "Waiting for $name at $url (up to ${timeout}s)..."
  local elapsed=0
  while ! curl -sf "$url" -o /dev/null; do
    sleep 3; elapsed=$((elapsed + 3))
    if [[ $elapsed -ge $timeout ]]; then
      log_warn "$name did not respond within ${timeout}s. It may still be starting."
      return 1
    fi
  done
  log_success "$name is up."
}

check_port_free() {
  local port="$1"
  if ss -tlnp "sport = :${port}" 2>/dev/null | grep -q ":${port}"; then
    return 1  # port in use
  fi
  return 0
}

# ─── Utility ───────────────────────────────────────────────────────────────────
confirm() {
  local msg="${1:-Continue?}"
  read -rp "$(echo -e "${YELLOW}${msg} [y/N]${RESET} ")" response
  [[ "${response,,}" == "y" ]]
}

print_summary() {
  local title="$1"; shift
  echo ""
  log_section "$title"
  while [[ $# -gt 0 ]]; do
    local key="$1" val="$2"; shift 2
    printf "  ${BOLD}%-24s${RESET} %s\n" "$key" "$val"
  done
  echo ""
}