#!/bin/sh
# Trident HTTP Cache Proxy - Universal Installer
#
# Usage:
#   curl -sSL https://get.trident-cache.com/install.sh | sh
#   curl -sSL https://get.trident-cache.com/install.sh | sh -s -- --prefix /opt/trident
#
# Options:
#   --prefix DIR      Installation prefix (default: /usr/local)
#   --version VER     Install specific version (default: latest)
#   --with-service    Install systemd service and default config
#   --help            Show this help

set -e

REPO="Trident-Cache/trident-cache"
PREFIX="/usr/local"
VERSION=""
INSTALL_SERVICE=false

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

info() {
    printf "\033[1;34m==>\033[0m %s\n" "$1"
}

error() {
    printf "\033[1;31mError:\033[0m %s\n" "$1" >&2
    exit 1
}

need_cmd() {
    if ! command -v "$1" >/dev/null 2>&1; then
        error "Required command not found: $1"
    fi
}

# ---------------------------------------------------------------------------
# Detect platform
# ---------------------------------------------------------------------------

detect_os() {
    case "$(uname -s)" in
        Linux*)  echo "linux" ;;
        Darwin*) echo "macos" ;;
        MINGW*|MSYS*|CYGWIN*) echo "windows" ;;
        *) error "Unsupported operating system: $(uname -s)" ;;
    esac
}

detect_arch() {
    case "$(uname -m)" in
        x86_64|amd64)  echo "x64" ;;
        aarch64|arm64) echo "arm64" ;;
        *) error "Unsupported architecture: $(uname -m)" ;;
    esac
}

# ---------------------------------------------------------------------------
# Fetch latest version from GitHub API
# ---------------------------------------------------------------------------

get_latest_version() {
    if command -v curl >/dev/null 2>&1; then
        curl -sSL "https://api.github.com/repos/${REPO}/releases/latest" \
            | grep '"tag_name"' | head -1 | sed 's/.*"tag_name": *"//;s/".*//'
    elif command -v wget >/dev/null 2>&1; then
        wget -qO- "https://api.github.com/repos/${REPO}/releases/latest" \
            | grep '"tag_name"' | head -1 | sed 's/.*"tag_name": *"//;s/".*//'
    else
        error "Neither curl nor wget found. Please install one of them."
    fi
}

# ---------------------------------------------------------------------------
# Download file
# ---------------------------------------------------------------------------

download() {
    url="$1"
    dest="$2"

    if command -v curl >/dev/null 2>&1; then
        curl -fsSL -o "$dest" "$url"
    elif command -v wget >/dev/null 2>&1; then
        wget -qO "$dest" "$url"
    else
        error "Neither curl nor wget found."
    fi
}

# ---------------------------------------------------------------------------
# Parse arguments
# ---------------------------------------------------------------------------

while [ $# -gt 0 ]; do
    case "$1" in
        --prefix)
            PREFIX="$2"
            shift 2
            ;;
        --version)
            VERSION="$2"
            shift 2
            ;;
        --with-service)
            INSTALL_SERVICE=true
            shift
            ;;
        --help)
            sed -n '2,/^$/s/^# \{0,1\}//p' "$0"
            exit 0
            ;;
        *)
            error "Unknown option: $1"
            ;;
    esac
done

# ---------------------------------------------------------------------------
# Main
# ---------------------------------------------------------------------------

OS="$(detect_os)"
ARCH="$(detect_arch)"

info "Detected platform: ${OS}/${ARCH}"

# Resolve version
if [ -z "$VERSION" ]; then
    info "Fetching latest release version..."
    VERSION="$(get_latest_version)"
    if [ -z "$VERSION" ]; then
        error "Could not determine latest version. Use --version to specify."
    fi
fi

info "Installing Trident ${VERSION}"

# Build artifact name
ARTIFACT="trident-${OS}-${ARCH}"
if [ "$OS" = "windows" ]; then
    EXT="zip"
else
    EXT="tar.gz"
fi

DOWNLOAD_URL="https://github.com/${REPO}/releases/download/${VERSION}/${ARTIFACT}.${EXT}"

# Download
TMPDIR="$(mktemp -d)"
trap 'rm -rf "$TMPDIR"' EXIT

info "Downloading ${DOWNLOAD_URL}"
download "$DOWNLOAD_URL" "${TMPDIR}/trident.${EXT}"

# Extract
info "Extracting..."
if [ "$EXT" = "tar.gz" ]; then
    tar -xzf "${TMPDIR}/trident.${EXT}" -C "$TMPDIR"
else
    need_cmd unzip
    unzip -q "${TMPDIR}/trident.${EXT}" -d "$TMPDIR"
fi

# Install binaries
info "Installing to ${PREFIX}/bin/"
mkdir -p "${PREFIX}/bin"

for bin in trident trident-cli trident-snap; do
    if [ "$OS" = "windows" ]; then
        bin="${bin}.exe"
    fi
    if [ -f "${TMPDIR}/${bin}" ]; then
        install -m 0755 "${TMPDIR}/${bin}" "${PREFIX}/bin/${bin}"
        info "  Installed ${bin}"
    fi
done

# Optionally install systemd service and config
if [ "$INSTALL_SERVICE" = true ] && [ "$OS" = "linux" ]; then
    info "Installing systemd service..."

    # Download dist files from the release tag
    BASE_RAW="https://raw.githubusercontent.com/${REPO}/${VERSION}"

    mkdir -p /etc/trident

    if [ ! -f /etc/trident/config.json ] && [ ! -f /etc/trident/config.toml ]; then
        info "  Installing default config to /etc/trident/config.json"
        download "${BASE_RAW}/dist/config.json" /etc/trident/config.json
    else
        info "  Existing config found, skipping"
    fi

    if [ ! -f /etc/default/trident ]; then
        download "${BASE_RAW}/dist/trident.default" /etc/default/trident
    fi

    download "${BASE_RAW}/dist/trident.service" /usr/lib/systemd/system/trident.service

    # Create system user
    if ! getent group trident >/dev/null 2>&1; then
        groupadd --system trident
    fi
    if ! getent passwd trident >/dev/null 2>&1; then
        useradd --system --gid trident --home-dir /var/lib/trident \
            --shell /usr/sbin/nologin --comment "Trident HTTP Cache Proxy" trident
    fi

    mkdir -p /var/lib/trident /var/log/trident
    chown trident:trident /var/lib/trident /var/log/trident

    systemctl daemon-reload

    info "  Service installed. Enable with: systemctl enable --now trident"
fi

# Verify
if command -v "${PREFIX}/bin/trident" >/dev/null 2>&1; then
    INSTALLED_VERSION="$("${PREFIX}/bin/trident" --version 2>/dev/null || echo "unknown")"
    info "Trident installed successfully: ${INSTALLED_VERSION}"
else
    info "Trident installed successfully to ${PREFIX}/bin/"
fi

info "Run 'trident --help' to get started."