#!/usr/bin/env bash
set -euo pipefail

# Check for required arguments
if [[ $# -ne 2 ]]; then
    echo "Usage: $0 <bun-version-tag> <install-directory>"
    echo "Example: $0 bun-v0.6.9 /path/to/install/dir"
    exit 1
fi

BUN_VERSION=$1
INSTALL_DIR=$2

# Ensure unzip is installed
command -v unzip >/dev/null ||
    { echo "Error: unzip is required to install Bun"; exit 1; }

# Detect platform
platform=$(uname -ms)
case "$platform" in
    "Darwin x86_64")
        target="darwin-x64"
        ;;
    "Darwin arm64")
        target="darwin-aarch64"
        ;;
    "Linux aarch64" | "Linux arm64")
        target="linux-aarch64"
        ;;
    "Linux x86_64")
        target="linux-x64"
        ;;
    "MINGW64"* | "Windows NT"*)
        target="windows-x64"
        ;;
    *)
        echo "Error: Unsupported platform $platform"
        exit 1
        ;;
esac

# Check for AVX2 support on x64 platforms
if [[ $target == "darwin-x64" || $target == "linux-x64" ]]; then
    if [[ $(uname) == "Darwin" ]]; then
        if ! sysctl -a | grep -q 'machdep.cpu.features.*AVX2'; then
            target="${target}-baseline"
        fi
    elif [[ $(uname) == "Linux" ]]; then
        if ! grep -q avx2 /proc/cpuinfo; then
            target="${target}-baseline"
        fi
    fi
fi

# Set download URL
GITHUB="${GITHUB:-https://github.com}"
github_repo="$GITHUB/oven-sh/bun"
bun_uri="$github_repo/releases/download/$BUN_VERSION/bun-$target.zip"

# Set installation directories
BIN_DIR="$INSTALL_DIR/bin"
EXE="$BIN_DIR/bun"

# Create installation directory
mkdir -p "$BIN_DIR" ||
    { echo "Error: Failed to create install directory \"$BIN_DIR\""; exit 1; }

# Download Bun
echo "Downloading Bun from $bun_uri..."
curl --fail --location --progress-bar --output "$EXE.zip" "$bun_uri" ||
    { echo "Error: Failed to download Bun from \"$bun_uri\""; exit 1; }

# Extract Bun
unzip -oqd "$BIN_DIR" "$EXE.zip" ||
    { echo "Error: Failed to extract Bun"; exit 1; }

# Move executable
if [[ "$target" == windows-* ]]; then
    mv "$BIN_DIR/bun-$target/bun.exe" "$EXE.exe" ||
        { echo "Error: Failed to move extracted Bun to destination"; exit 1; }
else
    mv "$BIN_DIR/bun-$target/bun" "$EXE" ||
        { echo "Error: Failed to move extracted Bun to destination"; exit 1; }
    # Set permissions
    chmod +x "$EXE" ||
        { echo "Error: Failed to set permissions on Bun executable"; exit 1; }
fi

# Clean up
rm -r "$BIN_DIR/bun-$target" "$EXE.zip"

echo "Bun was installed successfully to $EXE"

echo "You can run Bun with:"
if [[ "$target" == windows-* ]]; then
    echo "  \"$EXE.exe\""
else
    echo "  \"$EXE\""
fi