#!/bin/sh

set -u

say() {
	printf '%s\n' "$*"
}

warn() {
	printf '错误: %s\n' "$*" >&2
}

usage() {
	cat <<'EOF'
用法:
  ./search_config.sh
  ./search_config.sh --tavily KEY --exa KEY --keenable KEY

选项:
  --tavily KEY    配置 TAVILY_API_KEY
  --exa KEY       配置 EXA_API_KEY
  --keenable KEY  配置 KEENABLE_API_KEY
  --config FILE   覆盖配置文件路径
  -h, --help      显示帮助

不传 key 参数时进入隐藏输入的交互模式；传入任意 key 参数时不交互，
未指定的服务保留已有值。配置文件默认是 ~/.config/my-pi/search.env。
EOF
}

CONFIG_FILE=${MY_PI_SEARCH_CONFIG:-${XDG_CONFIG_HOME:-$HOME/.config}/my-pi/search.env}
mode=interactive
tavily_set=0
exa_set=0
keenable_set=0
tavily_value=
exa_value=
keenable_value=

while [ "$#" -gt 0 ]; do
	case $1 in
		--tavily)
			[ "$#" -ge 2 ] || { warn "--tavily 缺少 KEY"; exit 2; }
			tavily_value=$2; tavily_set=1; mode=noninteractive; shift 2 ;;
		--exa)
			[ "$#" -ge 2 ] || { warn "--exa 缺少 KEY"; exit 2; }
			exa_value=$2; exa_set=1; mode=noninteractive; shift 2 ;;
		--keenable)
			[ "$#" -ge 2 ] || { warn "--keenable 缺少 KEY"; exit 2; }
			keenable_value=$2; keenable_set=1; mode=noninteractive; shift 2 ;;
		--config)
			[ "$#" -ge 2 ] || { warn "--config 缺少 FILE"; exit 2; }
			CONFIG_FILE=$2; shift 2 ;;
		-h|--help) usage; exit 0 ;;
		*) warn "未知参数：$1"; usage >&2; exit 2 ;;
	esac
done

valid_key() {
	case $1 in
		''|*[!A-Za-z0-9._-]*) return 1 ;;
		*) return 0 ;;
	esac
}

read_existing() {
	existing_name=$1
	[ -f "$CONFIG_FILE" ] || return 0
	awk -v name="$existing_name" '
		$1 == "export" { sub(/^export[ \t]+/, "") }
		index($0, name "=") == 1 { print substr($0, length(name) + 2); exit }
	' "$CONFIG_FILE"
}

prompt_key() {
	prompt_label=$1
	prompt_current=$2
	if [ ! -t 0 ]; then
		warn "交互模式需要终端；请改用 --tavily/--exa/--keenable 参数。"
		return 2
	fi
	if [ -n "$prompt_current" ]; then
		printf '%s API key（回车保留现有值）: ' "$prompt_label" >&2
	else
		printf '%s API key（回车跳过）: ' "$prompt_label" >&2
	fi
	stty -echo
	IFS= read -r prompt_value || prompt_status=$?
	stty echo
	printf '\n' >&2
	[ "${prompt_status:-0}" -eq 0 ] || return "$prompt_status"
	printf '%s\n' "$prompt_value"
}

current_tavily=$(read_existing TAVILY_API_KEY)
current_exa=$(read_existing EXA_API_KEY)
current_keenable=$(read_existing KEENABLE_API_KEY)

if [ "$mode" = interactive ]; then
	tavily_value=$(prompt_key Tavily "$current_tavily") || exit $?
	exa_value=$(prompt_key Exa "$current_exa") || exit $?
	keenable_value=$(prompt_key Keenable "$current_keenable") || exit $?
	[ -n "$tavily_value" ] && tavily_set=1
	[ -n "$exa_value" ] && exa_set=1
	[ -n "$keenable_value" ] && keenable_set=1
fi

[ "$tavily_set" -eq 1 ] || tavily_value=$current_tavily
[ "$exa_set" -eq 1 ] || exa_value=$current_exa
[ "$keenable_set" -eq 1 ] || keenable_value=$current_keenable

for key_value in "$tavily_value" "$exa_value" "$keenable_value"; do
	[ -z "$key_value" ] || valid_key "$key_value" || {
		warn "API key 只能包含字母、数字、点、下划线和连字符。"
		exit 2
	}
done

config_dir=${CONFIG_FILE%/*}
[ "$config_dir" = "$CONFIG_FILE" ] && config_dir=.
umask 077
mkdir -p "$config_dir" || exit 1
config_tmp=$(mktemp "$config_dir/.search.env.XXXXXX") || exit 1
trap 'rm -f "$config_tmp"' EXIT HUP INT TERM
{
	printf '# Generated by my-pi/search_config.sh. Do not commit this file.\n'
	[ -z "$tavily_value" ] || printf 'export TAVILY_API_KEY=%s\n' "$tavily_value"
	[ -z "$exa_value" ] || printf 'export EXA_API_KEY=%s\n' "$exa_value"
	[ -z "$keenable_value" ] || printf 'export KEENABLE_API_KEY=%s\n' "$keenable_value"
} > "$config_tmp" || exit 1
chmod 600 "$config_tmp" || exit 1
mv "$config_tmp" "$CONFIG_FILE" || exit 1
trap - EXIT HUP INT TERM

say "搜索 API key 已安全写入 ${CONFIG_FILE}（权限 600）。"
say "重启 Pi 后生效；显式环境变量仍优先于该文件。"