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

# Downloads and installs the latest lazydocker from
# https://github.com/jesseduffield/lazydocker/releases
#
# Supported platforms:
#   macOS    : Apple Silicon (arm64), Intel (x86_64)
#   Linux    : x86_64, aarch64/arm64, armv6, armv7, x86 (32-bit)
#   Windows  : Not supported — use install-lazydocker.ps1 (PowerShell)

set -euo pipefail

# ────────────────────────────────────────────
# Constants
# ────────────────────────────────────────────
REPO="jesseduffield/lazydocker"
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
# ────────────────────────────────────────────
# Returns: "<platform>:<archive_format>"
#   platform matches lazydocker's GitHub release asset naming
detect_platform() {
	local os arch

	os="$(uname -s)"
	arch="$(uname -m)"

	case "$os" in
	# ── macOS ──────────────────────────────────────────────
	Darwin)
		case "$arch" in
		arm64) echo "Darwin_arm64:tar.gz" ;;
		x86_64) echo "Darwin_x86_64:tar.gz" ;;
		*) error "Unsupported macOS architecture: $arch" ;;
		esac
		;;

	# ── Linux ──────────────────────────────────────────────
	Linux)
		case "$arch" in
		x86_64 | amd64) echo "Linux_x86_64:tar.gz" ;;
		aarch64 | arm64) echo "Linux_arm64:tar.gz" ;;
		armv7l) echo "Linux_armv7:tar.gz" ;;
		armv6l) echo "Linux_armv6:tar.gz" ;;
		i686 | i386) echo "Linux_x86:tar.gz" ;;
		*) error "Unsupported Linux architecture: $arch" ;;
		esac
		;;

	# ── Windows (Git Bash / MSYS2 / Cygwin) ───────────────
	MINGW* | MSYS* | CYGWIN*)
		error "Windows is not supported by this script. Use install-lazydocker.ps1 instead."
		;;

	*)
		error "Unsupported OS: $os  (uname -a: $(uname -a))"
		;;
	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
# ────────────────────────────────────────────
build_download_url() {
	local tag="$1"
	local platform="$2"      # e.g. Darwin_arm64, Linux_x86_64
	local ext="$3"           # tar.gz | zip
	local version="${tag#v}" # Remove 'v' prefix

	local filename="lazydocker_${version}_${platform}.${ext}"
	echo "https://github.com/${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 to extract .zip files."
		fi
		;;
	*)
		error "Unknown archive format: $ext"
		;;
	esac

	# Binary name
	local bin_name="lazydocker"

	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 is_macos tag url

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

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

	is_macos="false"
	[[ "$platform" == "Darwin"* ]] && is_macos="true"

	# macOS: try Homebrew first
	if [[ "$is_macos" == "true" ]]; then
		if command -v lazydocker &>/dev/null; then
			local current_ver
			current_ver="$(lazydocker --version 2>/dev/null || echo 'unknown')"
			info "lazydocker is already installed ($current_ver). Skipping installation."
		else
			ensure_brew
			brew install lazydocker
			success "lazydocker installed via Homebrew"
		fi
	else
		if command -v lazydocker &>/dev/null; then
			local current_ver
			current_ver="$(lazydocker --version 2>/dev/null || echo 'unknown')"
			info "lazydocker 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 lazydocker is available
	if command -v lazydocker &>/dev/null; then
		success "lazydocker is available: $(command -v lazydocker)"
	else
		warn "lazydocker was not found in PATH after installation. You may need to open a new terminal."
	fi
}

main "$@"