#!/usr/bin/env bash
# shellcheck disable=SC2086

# Downloads and installs the latest superfile from
# https://github.com/yorukot/superfile/releases
#
# Supported platforms:
#   macOS    : Apple Silicon (arm64), Intel (x86_64) — via Homebrew or direct download
#   Linux    : x86_64 (amd64), aarch64/arm64 — via direct download
#   Windows  : Not supported — use install-superfile.ps1 (PowerShell)

set -euo pipefail

# ────────────────────────────────────────────
# Constants
# ────────────────────────────────────────────
REPO="yorukot/superfile"
API_URL="https://api.github.com/repos/${REPO}/releases"
INSTALL_DIR="${HOME}/.local/bin"

# ────────────────────────────────────────────
# Utility functions (all stderr output)
# ────────────────────────────────────────────
info()    { echo "[INFO]  $*" >&2; }
warn()    { echo "[WARN]  $*" >&2; }
error()   { echo "[ERROR] $*" >&2; exit 1; }
success() { echo "[OK]    $*" >&2; }

# ────────────────────────────────────────────
# Ensure Homebrew is available on macOS
# ────────────────────────────────────────────
ensure_brew() {
	if command -v brew &>/dev/null; then
		return 0
	fi
	info "Homebrew is not installed. Installing Homebrew..."
	/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
	if [ -d /opt/homebrew/bin ]; then
		export PATH="/opt/homebrew/bin:$PATH"
	fi
	if [ -d /usr/local/bin ]; then
		export PATH="/usr/local/bin:$PATH"
	fi
	command -v brew &>/dev/null || error "Homebrew installation failed. Install it manually: https://brew.sh/"
	success "Homebrew installed"
}

# ────────────────────────────────────────────
# Check required commands
# ────────────────────────────────────────────
for cmd in curl uname; do
	command -v "$cmd" &>/dev/null || error "'$cmd' command is required."
done

# Fallback: use python3 if jq is not available
if command -v jq &>/dev/null; then
	_json_latest_tag() {
		jq -r '[.[] | select(.prerelease==false)] | .[0].tag_name'
	}
else
	command -v python3 &>/dev/null || error "'jq' or 'python3' is required."
	_json_latest_tag() {
		python3 -c "
import sys, json
data = json.load(sys.stdin)
for r in data:
    if not r.get('prerelease'):
        print(r['tag_name'])
        break
"
	}
fi

# ────────────────────────────────────────────
# OS / Architecture detection
# ────────────────────────────────────────────
OS="$(uname -s)"
ARCH="$(uname -m)"

case "$OS" in
Darwin | Linux) ;;
*)
	error "Unsupported OS: $OS. This script only supports macOS and Linux."
	;;
esac

# Returns: "<platform>:<archive_format>"
detect_platform() {
	case "$OS" in
	Darwin)
		case "$ARCH" in
			arm64)  echo "darwin-arm64:tar.gz" ;;
			x86_64) echo "darwin-amd64:tar.gz" ;;
			*)      error "Unsupported macOS architecture: $ARCH" ;;
		esac
		;;
	Linux)
		case "$ARCH" in
			x86_64|amd64) echo "linux-amd64:tar.gz" ;;
			aarch64|arm64) echo "linux-arm64:tar.gz" ;;
			*)             error "Unsupported Linux architecture: $ARCH" ;;
		esac
		;;
esac
}

# ────────────────────────────────────────────
# Get latest stable release tag
# ────────────────────────────────────────────
get_latest_tag() {
	info "Fetching latest release from GitHub API..."

	local releases
	releases="$(curl -fsSL "${API_URL}")" || error "Failed to call GitHub API."

	local tag
	tag="$(echo "$releases" | _json_latest_tag)"

	[[ -z "$tag" || "$tag" == "null" ]] && error "Could not find latest release tag."
	echo "$tag"
}

# ────────────────────────────────────────────
# Build download URL
# ────────────────────────────────────────────
# Asset naming: superfile-{os}-{tag_version}-{arch}.tar.gz
build_download_url() {
	local tag="$1"
	local platform="$2"   # e.g. darwin-arm64
	local ext="$3"        # tar.gz | zip
	local version="${tag#v}"

	local filename="superfile-${platform}-${tag}.${ext}"
	echo "https://github.com/${REPO}/releases/download/${tag}/${filename}"
}

# ────────────────────────────────────────────
# Download, extract & install
# ────────────────────────────────────────────
download_and_install() {
	local url="$1"
	local ext="$2"

	local tmpdir
	tmpdir="$(mktemp -d)"
	trap '[[ -d "${tmpdir:-}" ]] && rm -rf "$tmpdir"' EXIT

	local filename
	filename="${url##*/}"

	info "Downloading: $url"
	curl -fsSL --progress-bar -o "${tmpdir}/${filename}" "$url" \
		|| error "Download failed: $url"

	info "Extracting..."
	case "$ext" in
		tar.gz)
			command -v tar &>/dev/null || error "'tar' command is required."
			tar -xzf "${tmpdir}/${filename}" -C "$tmpdir"
			;;
		zip)
			if command -v unzip &>/dev/null; then
				unzip -q "${tmpdir}/${filename}" -d "$tmpdir"
			elif command -v tar &>/dev/null; then
				tar -xf "${tmpdir}/${filename}" -C "$tmpdir"
			else
				error "'unzip' or 'tar' is required."
			fi
			;;
		*)
			error "Unknown archive format: $ext"
			;;
	esac

	# Binary name
	local bin_name="spf"
	[[ "$OS" == "MINGW"* || "$OS" == "MSYS"* || "$OS" == "CYGWIN"* ]] && bin_name="spf.exe"

	local bin_src
	bin_src="$(find "$tmpdir" -maxdepth 3 -type f -name "$bin_name" | head -1)"
	[[ -z "$bin_src" ]] && error "Cannot find '$bin_name' in the archive."

	# Create install directory
	mkdir -p "$INSTALL_DIR"

	local install_path="${INSTALL_DIR}/${bin_name}"
	info "Installing: ${install_path}"
	cp "$bin_src" "$install_path"
	chmod +x "$install_path"

	success "Installation complete!"
	info "Version check:"
	"$install_path" --version || true

	# PATH instructions
	if ! echo ":${PATH}:" | grep -q ":${INSTALL_DIR}:"; then
		warn "'${INSTALL_DIR}' is not in your PATH."
		warn "Add this line to your ~/.bashrc or ~/.zshrc:"
		warn "  export PATH=\"\$HOME/.local/bin:\$PATH\""
	fi
}

# ────────────────────────────────────────────
# Main
# ────────────────────────────────────────────
main() {
	local platform_info platform ext tag url

	platform_info="$(detect_platform)"
	platform="${platform_info%%:*}"
	ext="${platform_info##*:}"

	info "Detected platform: $platform  (format: $ext)"

	# macOS: try Homebrew first
	if [[ "$OS" == "Darwin" ]]; then
		if command -v spf &>/dev/null; then
			local current_ver
			current_ver="$(spf --version 2>/dev/null || echo 'unknown')"
			info "superfile is already installed ($current_ver). Skipping installation."
		else
			ensure_brew
			brew install superfile
			success "superfile installed via Homebrew"
		fi
	else
		if command -v spf &>/dev/null; then
			local current_ver
			current_ver="$(spf --version 2>/dev/null || echo 'unknown')"
			info "superfile is already installed ($current_ver). Skipping installation."
		else
			tag="$(get_latest_tag)"
			info "Latest release: $tag"

			url="$(build_download_url "$tag" "$platform" "$ext")"
			download_and_install "$url" "$ext"
		fi
	fi

	# Verify spf is available
	if command -v spf &>/dev/null; then
		success "superfile is available: $(command -v spf)"
	else
		warn "superfile was not found in PATH after installation. You may need to open a new terminal."
	fi
}

main "$@"