#!/usr/bin/env sh
# park installer.
#
# Usage:
#   curl -fsSL https://raw.githubusercontent.com/mr-vaibh/park/main/install.sh | sh
#   curl -fsSL https://raw.githubusercontent.com/mr-vaibh/park/main/install.sh | sh -s -- --bin-dir ~/.local/bin
#
# What this does:
#   1. Detects your OS and architecture.
#   2. Downloads the latest release binary from GitHub.
#   3. Drops it into /usr/local/bin (or your chosen --bin-dir), creating
#      it with sudo only if needed.
#   4. Verifies that 'park' is on your PATH and prints a one-line next step.
#
# If no release binary is available for your platform, the script falls back
# to 'go install github.com/mr-vaibh/park/cmd/park@latest' so you still get a
# working binary if you have Go.

set -eu

REPO="mr-vaibh/park"
BIN_NAME="park"
BIN_DIR="/usr/local/bin"
VERSION=""

while [ $# -gt 0 ]; do
	case "$1" in
		--bin-dir) BIN_DIR="$2"; shift 2 ;;
		--version) VERSION="$2"; shift 2 ;;
		-h|--help)
			sed -n '2,18p' "$0" | sed 's/^# \{0,1\}//'
			exit 0
			;;
		*) echo "unknown flag: $1" >&2; exit 2 ;;
	esac
done

say()  { printf '\033[1;34m==>\033[0m %s\n' "$*"; }
warn() { printf '\033[1;33m!!\033[0m  %s\n' "$*" >&2; }
die()  { printf '\033[1;31mxx\033[0m  %s\n' "$*" >&2; exit 1; }

# ---- detect platform -----------------------------------------------------
uname_s=$(uname -s)
uname_m=$(uname -m)

case "$uname_s" in
	Linux)  os=linux ;;
	Darwin) os=darwin ;;
	*) die "unsupported OS: $uname_s (park supports Linux and macOS)" ;;
esac

case "$uname_m" in
	x86_64|amd64) arch=amd64 ;;
	arm64|aarch64) arch=arm64 ;;
	*) die "unsupported architecture: $uname_m" ;;
esac

say "platform: ${os}/${arch}"

# Honest warning so users aren't surprised.
case "${os}/${arch}" in
	linux/amd64)
		: # fully supported
		;;
	darwin/arm64)
		warn "macOS arm64 (Apple Silicon): full park + resume works for"
		warn "asyncio frameworks (uvicorn, FastAPI, Flask, python http.server)."
		warn "Go's net/http and libuv-based servers don't survive resume yet —"
		warn "for those, use 'park release <pid>' to clean up, or use Linux."
		;;
	*)
		warn "Your platform (${os}/${arch}) does not have a working live"
		warn "injection layer. The binary installs fine and 'park list' works,"
		warn "but 'park <port>' will return ErrUnsupported. Patches welcome."
		;;
esac

# ---- resolve version -----------------------------------------------------
if [ -z "$VERSION" ]; then
	say "resolving latest release..."
	if command -v curl >/dev/null 2>&1; then
		VERSION=$(curl -fsSL "https://api.github.com/repos/${REPO}/releases/latest" 2>/dev/null | sed -n 's/.*"tag_name": *"\([^"]*\)".*/\1/p' | head -n1 || true)
	elif command -v wget >/dev/null 2>&1; then
		VERSION=$(wget -qO- "https://api.github.com/repos/${REPO}/releases/latest" 2>/dev/null | sed -n 's/.*"tag_name": *"\([^"]*\)".*/\1/p' | head -n1 || true)
	else
		die "need either curl or wget"
	fi
fi

# ---- try downloading a release binary ------------------------------------
install_from_release() {
	[ -n "$VERSION" ] || return 1

	asset="park_${VERSION#v}_${os}_${arch}.tar.gz"
	url="https://github.com/${REPO}/releases/download/${VERSION}/${asset}"
	tmp=$(mktemp -d)
	trap 'rm -rf "$tmp"' EXIT

	say "downloading ${asset}"
	if command -v curl >/dev/null 2>&1; then
		curl -fsSL "$url" -o "${tmp}/${asset}" || return 1
	else
		wget -q "$url" -O "${tmp}/${asset}" || return 1
	fi

	tar -xzf "${tmp}/${asset}" -C "$tmp" || return 1
	[ -f "${tmp}/${BIN_NAME}" ] || return 1

	install_binary "${tmp}/${BIN_NAME}"
}

# ---- fallback: go install ------------------------------------------------
install_from_source() {
	if ! command -v go >/dev/null 2>&1; then
		die "no release binary found and Go is not installed.

Either:
  1. Wait until a release is published for ${os}/${arch}, or
  2. Install Go (https://go.dev/dl/) and re-run this script."
	fi
	say "no prebuilt binary; falling back to: go install github.com/${REPO}/cmd/park@${VERSION:-latest}"
	GOBIN=$(mktemp -d)
	export GOBIN
	go install "github.com/${REPO}/cmd/park@${VERSION:-latest}"
	install_binary "${GOBIN}/${BIN_NAME}"
	rm -rf "$GOBIN"
}

# ---- copy binary into BIN_DIR (with sudo if necessary) -------------------
install_binary() {
	src="$1"
	chmod +x "$src"

	# On macOS, ad-hoc sign with the debugger entitlement so that
	# task_for_pid() can attach to processes you own. Without this, park
	# is functionally useless on macOS — every attach fails. We do this
	# *before* moving to BIN_DIR so we don't need sudo for the codesign
	# step.
	if [ "$os" = "darwin" ] && command -v codesign >/dev/null 2>&1; then
		say "ad-hoc signing for task_for_pid (macOS)"
		ent=$(mktemp -t park-entitlements.XXXXXX)
		cat > "$ent" <<'PLIST'
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>com.apple.security.cs.debugger</key><true/>
  <key>com.apple.security.get-task-allow</key><true/>
</dict>
</plist>
PLIST
		if ! codesign --entitlements "$ent" -fs - "$src" 2>/dev/null; then
			warn "codesign failed; park <port> will probably hit task_for_pid permission errors."
			warn "you can re-sign manually: codesign --entitlements <plist> -fs - $(command -v park)"
		fi
		rm -f "$ent"
	fi

	if [ ! -d "$BIN_DIR" ]; then
		mkdir -p "$BIN_DIR" 2>/dev/null || sudo mkdir -p "$BIN_DIR"
	fi

	dst="${BIN_DIR}/${BIN_NAME}"
	if [ -w "$BIN_DIR" ]; then
		install -m 0755 "$src" "$dst"
	else
		say "writing to ${dst} requires sudo"
		sudo install -m 0755 "$src" "$dst"
	fi
	say "installed ${dst}"
}

if ! install_from_release; then
	install_from_source
fi

# ---- post-install path check ---------------------------------------------
if ! command -v park >/dev/null 2>&1; then
	case ":$PATH:" in
		*":${BIN_DIR}:"*) ;;
		*)
			warn "${BIN_DIR} is not on your PATH. Add it with one of:"
			warn "  echo 'export PATH=\"\$PATH:${BIN_DIR}\"' >> ~/.zshrc && source ~/.zshrc"
			warn "  echo 'export PATH=\"\$PATH:${BIN_DIR}\"' >> ~/.bashrc && source ~/.bashrc"
			;;
	esac
fi

say "done. try:  park --help"
if [ "$os" = "linux" ] && [ "$arch" = "amd64" ]; then
	echo
	echo "  one-time: lower yama ptrace_scope so park can attach to non-descendants"
	echo "    echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope"
fi