#!/usr/bin/env bash
#
# vocat install / update script for binary + systemd deployments.
#
# Usage:
#   sudo bash install.sh [version]        # install a specific version
#   sudo bash install.sh                  # install latest release
#   sudo bash install.sh --force          # reinstall even at the same version
#   curl -fsSL <raw url> | sudo bash      # one-liner (latest)
#
# Behavior:
#   - Prompts for script language (中文 / English) as soon as it runs.
#   - If the installed version equals the target version, does nothing (unless --force).
#   - On first install, generates a random 32-char admin password, writes it to
#     /etc/vocat/env (0600, loaded by the systemd unit), and prints it ONCE.
#   - On update, preserves the existing env file and credentials.
#   - (Re)writes the systemd unit and restarts the service.
#
# Published script: must contain no secrets, IPs, or passwords.

set -euo pipefail

# --- Publisher configuration -------------------------------------------------
# Default GitHub repository in owner/name form. Publishers: set this to your
# own repo, or override per-run with VOCAT_REPO.
REPO="${VOCAT_REPO:-MengMengCode/VoCat}"

INSTALL_DIR="/opt/vocat/bin"
BINARY_PATH="${INSTALL_DIR}/vocat"
ENV_DIR="/etc/vocat"
ENV_FILE="${ENV_DIR}/env"
UNIT_PATH="/etc/systemd/system/vocat.service"
VOCAT_USER="vocat"

# --- Language ----------------------------------------------------------------
LANG_CHOICE=""

msg() {
    # $1 = zh text, $2 = en text
    if [ "$LANG_CHOICE" = "en" ]; then
        printf '%s\n' "$2"
    else
        printf '%s\n' "$1"
    fi
}

prompt_language() {
    while true; do
        echo "选择语言 / Select language:  1) 中文   2) English"
        printf '> '
        read -r choice
        case "$choice" in
            1|"") LANG_CHOICE="zh"; return ;;
            2) LANG_CHOICE="en"; return ;;
        esac
    done
}

die() {
    msg "$1" "$2" >&2
    exit 1
}

# --- Root --------------------------------------------------------------------
[ "$(id -u)" -eq 0 ] || die "请以 root 身份运行此脚本。" "Run this script as root."

prompt_language

# --- Parse args --------------------------------------------------------------
FORCE=0
TARGET_VERSION=""
for arg in "$@"; do
    case "$arg" in
        --force) FORCE=1 ;;
        -h|--help)
            msg "用法: sudo bash install.sh [--force] [版本]" "Usage: sudo bash install.sh [--force] [version]"
            exit 0
            ;;
        *) TARGET_VERSION="${arg#v}" ;;
    esac
done

# --- Resolve target version --------------------------------------------------
resolve_target_version() {
    if [ -n "$TARGET_VERSION" ]; then
        TARGET_VERSION="${TARGET_VERSION#v}"
        return
    fi
    local api_url="https://api.github.com/repos/${REPO}/releases/latest"
    local auth_hdr=()
    if [ -n "${GITHUB_TOKEN:-}" ]; then
        auth_hdr=(-H "Authorization: Bearer ${GITHUB_TOKEN}")
    fi
    local resp
    resp=$(curl -fsSL "${auth_hdr[@]}" "$api_url") || die "无法获取最新版本信息。检查网络或 REPO 设置。" "Failed to fetch latest release. Check network or REPO."
    # Parse "tag_name": "vX.Y.Z" without jq.
    local tag
    tag=$(printf '%s\n' "$resp" | grep -m1 '"tag_name"' | sed -E 's/.*"tag_name"[[:space:]]*:[[:space:]]*"([^"]+)".*/\1/')
    [ -n "$tag" ] || die "无法解析最新版本的 tag_name。" "Could not parse tag_name from the release response."
    TARGET_VERSION="${tag#v}"
}

# --- Skip if already installed at the same version ---------------------------
skip_if_equal() {
    [ -x "$BINARY_PATH" ] || return 0
    [ "$FORCE" -eq 1 ] && return 0
    local installed
    installed=$("$BINARY_PATH" version 2>/dev/null | awk '{print $2}' | sed -E 's/[[:space:]]*\(.*$//') || return 0
    [ -z "$installed" ] && return 0
    if [ "$installed" = "$TARGET_VERSION" ]; then
        msg "已安装版本 $installed，与目标版本相同，跳过更新。" "Installed version $installed equals target; skipping."
        exit 0
    fi
    msg "当前 $installed -> $TARGET_VERSION，开始更新。" "Updating $installed -> $TARGET_VERSION."
}

# --- Detect architecture -----------------------------------------------------
detect_arch() {
    case "$(uname -m)" in
        x86_64) ARCH="amd64" ;;
        i386|i486|i586|i686) ARCH="386" ;;
        aarch64|arm64) ARCH="arm64" ;;
        armv7l|armv7*) ARCH="armv7" ;;
        *) die "不支持的架构: $(uname -m)" "Unsupported architecture: $(uname -m)" ;;
    esac
}

# --- Download + verify -------------------------------------------------------
VOCAT_TMP=""
download_and_verify() {
    VOCAT_TMP=$(mktemp -d)
    trap 'rm -rf "$VOCAT_TMP"' EXIT
    local base="https://github.com/${REPO}/releases/download/v${TARGET_VERSION}"
    local asset="vocat-linux-${ARCH}"
    msg "下载 $asset ..." "Downloading $asset ..."
    curl -fsSL -o "${VOCAT_TMP}/vocat" "${base}/${asset}" || die "下载二进制失败。" "Failed to download the binary."
    curl -fsSL -o "${VOCAT_TMP}/SHA256SUMS" "${base}/SHA256SUMS" || die "下载 SHA256SUMS 失败。" "Failed to download SHA256SUMS."

    local expected actual
    # Match a line whose filename field equals the asset (with optional binary-mode * prefix).
    expected=$(awk -v a="$asset" '$2 == a || $2 == ("*" a) {print $1; exit}' "${VOCAT_TMP}/SHA256SUMS")
    [ -n "$expected" ] || die "SHA256SUMS 中找不到 $asset 的校验行。" "$asset not found in SHA256SUMS."
    actual=$(sha256sum "${VOCAT_TMP}/vocat" | awk '{print $1}')
    [ "$actual" = "$expected" ] || die "SHA-256 校验失败。" "SHA-256 verification failed."
}

# --- Install binary ----------------------------------------------------------
install_binary() {
    install -d -m 0755 "$INSTALL_DIR"
    install -m 0755 "${VOCAT_TMP}/vocat" "$BINARY_PATH"
}

# --- System user (idempotent) ------------------------------------------------
ensure_user() {
    if id "$VOCAT_USER" >/dev/null 2>&1; then
        return
    fi
    useradd --system --no-create-home --shell /usr/sbin/nologin "$VOCAT_USER"
}

# --- Data directory ----------------------------------------------------------
ensure_data_dir() {
    install -d -m 0755 /opt/vocat/data
    chown -R "$VOCAT_USER":"$VOCAT_USER" /opt/vocat || true
}

# --- Env file (first install only) -------------------------------------------
# Generates a random 32-char secret, stores it in the 0600 env file, and flags
# FIRST_INSTALL so we can print the secret once at the end.
FIRST_INSTALL=0
setup_env() {
    if [ -f "$ENV_FILE" ]; then
        return
    fi
    install -d -m 0755 "$ENV_DIR"
    local secret
    secret=$(tr -dc 'A-Za-z0-9' </dev/urandom | head -c 32)
    [ -n "$secret" ] || die "生成随机密钥失败。" "Failed to generate a random secret."
    printf 'VOCAT_ADMIN_PASSWORD=%s\n' "$secret" > "$ENV_FILE"
    chmod 0600 "$ENV_FILE"
    FIRST_INSTALL=1
}

# --- systemd unit ------------------------------------------------------------
write_unit() {
    cat > "$UNIT_PATH" <<EOF
[Unit]
Description=vocat
After=network.target

[Service]
User=${VOCAT_USER}
EnvironmentFile=${ENV_FILE}
Environment=VOCAT_DATABASE_PATH=/opt/vocat/data/vocat.db
ExecStart=${BINARY_PATH}
Restart=on-failure

[Install]
WantedBy=multi-user.target
EOF
    chmod 0644 "$UNIT_PATH"
}

enable_and_start() {
    systemctl daemon-reload
    systemctl enable --now vocat
}

# --- Main --------------------------------------------------------------------
resolve_target_version
detect_arch
skip_if_equal
download_and_verify
install_binary
ensure_user
ensure_data_dir
setup_env
write_unit
enable_and_start

if [ "$FIRST_INSTALL" -eq 1 ]; then
    secret=$(grep -E '^VOCAT_ADMIN_PASSWORD=' "$ENV_FILE" | cut -d= -f2-)
    echo
    msg "================ 安装完成 ================" "================ Install complete ================"
    msg "首次安装已生成管理员初始密码 (仅显示一次):" "First-install admin password (shown once):"
    echo
    echo "    $secret"
    echo
    msg "用户名为 admin。请立即记录此密码。" "Username is admin. Record this password now."
    msg "登录后或运行以下命令修改密码:" "Change it via the web UI or run:"
    echo "    sudo vocat menu"
    msg "==========================================" "=============================================="
else
    echo
    msg "================ 更新完成 ================" "================ Update complete ================"
    msg "已更新到 $TARGET_VERSION，服务已重启。" "Updated to $TARGET_VERSION; service restarted."
    msg "管理员密码保持不变。" "Admin password unchanged."
    msg "==========================================" "=============================================="
fi