#!/bin/sh
# Copyright © 2026 Akyros Labs LLC. All rights reserved.
# SPDX-License-Identifier: BUSL-1.1
#
# PromptGate installer for Linux and macOS:
#
#   curl -fsSL https://install.promptgate.dev/install.sh | sh
#
# Environment:
#   PROMPTGATE_VERSION      tag to install, e.g. v0.1.0 (default: latest)
#   PROMPTGATE_INSTALL_DIR  target directory (default: /usr/local/bin if
#                           writable, else ~/.local/bin)
#   PROMPTGATE_BASE_URL     download root (default: https://install.promptgate.dev)
set -eu

BASE_URL="${PROMPTGATE_BASE_URL:-https://install.promptgate.dev}"
VERSION="${PROMPTGATE_VERSION:-latest}"

say() { printf '%s\n' "$*"; }
fail() { printf 'promptgate install: %s\n' "$*" >&2; exit 1; }

detect_platform() {
	case "$(uname -s)" in
		Linux) os=linux ;;
		Darwin) os=darwin ;;
		*) fail "unsupported OS $(uname -s) — on Windows use install.ps1" ;;
	esac
	case "$(uname -m)" in
		x86_64 | amd64) arch=amd64 ;;
		aarch64 | arm64) arch=arm64 ;;
		*) fail "unsupported architecture $(uname -m)" ;;
	esac
}

download() { # url file
	if command -v curl >/dev/null 2>&1; then
		curl -fsSL --retry 3 -o "$2" "$1"
	elif command -v wget >/dev/null 2>&1; then
		wget -q -O "$2" "$1"
	else
		fail "need curl or wget"
	fi
}

sha256_of() {
	if command -v sha256sum >/dev/null 2>&1; then
		sha256sum "$1" | cut -d' ' -f1
	elif command -v shasum >/dev/null 2>&1; then
		shasum -a 256 "$1" | cut -d' ' -f1
	else
		fail "need sha256sum or shasum to verify the download"
	fi
}

choose_dir() {
	if [ -n "${PROMPTGATE_INSTALL_DIR:-}" ]; then
		dir="$PROMPTGATE_INSTALL_DIR"
	elif [ -w /usr/local/bin ]; then
		dir=/usr/local/bin
	else
		dir="$HOME/.local/bin"
	fi
	mkdir -p "$dir"
}

main() {
	detect_platform
	name="promptgate-$os-$arch"
	tmp="$(mktemp -d)"
	trap 'rm -rf "$tmp"' EXIT INT TERM

	say "Downloading PromptGate ($VERSION, $os/$arch)…"
	download "$BASE_URL/$VERSION/$name" "$tmp/promptgate"
	download "$BASE_URL/$VERSION/checksums.txt" "$tmp/checksums.txt"

	want="$(awk -v n="$name" '$2 == n { print $1 }' "$tmp/checksums.txt")"
	[ -n "$want" ] || fail "$name is not listed in checksums.txt"
	got="$(sha256_of "$tmp/promptgate")"
	[ "$want" = "$got" ] || fail "checksum mismatch for $name — refusing to install"

	choose_dir
	chmod 755 "$tmp/promptgate"
	mv "$tmp/promptgate" "$dir/promptgate"
	say "Installed $("$dir/promptgate" version) to $dir/promptgate"

	case ":$PATH:" in
		*":$dir:"*) ;;
		*) say "Note: $dir is not on your PATH — add: export PATH=\"$dir:\$PATH\"" ;;
	esac
	say ""
	say "Next steps:"
	say "  promptgate setup     # writes a config, creates your first pg_ key"
	say "  promptgate start"
}

main "$@"