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

# Installs dua (Disk Usage Analyzer) — https://github.com/byron/dua-cli
#
# Supported platforms:
#   macOS    : Apple Silicon (arm64), Intel (x86_64) — via Homebrew
#   Linux    : x86_64, aarch64 — via package manager or curl installer
#
# Prerequisites:
#   - macOS: Homebrew (brew) — auto-installed if missing
#   - Linux: curl — for curl-based installer

set -euo pipefail

# ────────────────────────────────────────────
# Constants
# ────────────────────────────────────────────
REPO="Byron/dua-cli"

# ────────────────────────────────────────────
# 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"
}

# ────────────────────────────────────────────
# Detect OS
# ────────────────────────────────────────────
OS="$(uname -s)"
ARCH="$(uname -m)"

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

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

# ────────────────────────────────────────────
# Step 1: Install dua
# ────────────────────────────────────────────
info "Installing dua (Disk Usage Analyzer)..."

if command -v dua &>/dev/null; then
	CURRENT_VER="$(dua --version 2>/dev/null || echo 'unknown')"
	info "dua is already installed ($CURRENT_VER). Skipping installation."
else
	case "$OS" in
	Darwin)
		ensure_brew
		brew install dua-cli
		success "dua installed via Homebrew"
		;;
	Linux)
		# Try package managers first, fall back to curl installer
		if command -v apt-get &>/dev/null; then
			# dua-cli is available in newer Ubuntu/Debian repos
			info "Installing via apt-get..."
			sudo apt-get update -y 2>/dev/null || true
			if sudo apt-get install -y dua-cli 2>/dev/null; then
				success "dua installed via apt-get"
			else
				info "dua-cli not in apt repos. Using curl installer..."
				curl -LSfs https://raw.githubusercontent.com/Byron/dua-cli/master/ci/install.sh |
					sh -s -- --git Byron/dua-cli --crate dua --target x86_64-unknown-linux-musl
				success "dua installed via curl installer"
			fi
		elif command -v dnf &>/dev/null; then
			sudo dnf install -y dua-cli
			success "dua installed via dnf"
		elif command -v pacman &>/dev/null; then
			sudo pacman -S --noconfirm dua-cli
			success "dua installed via pacman"
		elif command -v zypper &>/dev/null; then
			sudo zypper -n install dua-cli
			success "dua installed via zypper"
		else
			info "No supported package manager found. Using curl installer..."
			# Determine target
			case "$ARCH" in
			x86_64 | amd64) TARGET="x86_64-unknown-linux-musl" ;;
			aarch64 | arm64) TARGET="aarch64-unknown-linux-musl" ;;
			*) error "Unsupported Linux architecture: $ARCH" ;;
			esac
			curl -LSfs https://raw.githubusercontent.com/Byron/dua-cli/master/ci/install.sh |
				sh -s -- --git Byron/dua-cli --crate dua --target "$TARGET"
			success "dua installed via curl installer"
		fi
		;;
	esac
fi

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

# ────────────────────────────────────────────
# Step 2: Post-install notes
# ────────────────────────────────────────────
info ""
info "=================================================="
success "dua installation complete!"
info "=================================================="
info ""
info "Getting started:"
info "  dua                     - Show disk usage of current directory"
info "  dua /path/to/dir        - Show disk usage of specific directory"
info "  dua i                   - Interactive mode (explore & delete)"
info "  dua --help              - Show help"
info ""
info "Interactive mode shortcuts:"
info "  Arrow keys / h/j/k/l   - Navigate"
info "  ?                       - Show help"
info "  d                       - Delete selected entry"
info "  q / Esc                 - Quit"