#!/bin/bash

set -e  # Exit on error

# Detect OS (linux, darwin, windows)
OS_TYPE=$(uname | tr '[:upper:]' '[:lower:]')

# Detect Architecture (amd64, arm64, 386)
ARCH_TYPE=$(uname -m)
case "$ARCH_TYPE" in
    x86_64) ARCH="amd64" ;;
    arm64 | aarch64) ARCH="arm64" ;;
    i386 | i686) ARCH="386" ;;
    *) echo "❌ Unsupported architecture: $ARCH_TYPE"; exit 1 ;;
esac

# Detect shell (bash or zsh)
SHELL_RC="$HOME/.bashrc"
[ -n "$ZSH_VERSION" ] && SHELL_RC="$HOME/.zshrc"

# Get the latest Go version
GO_VERSION=$(curl -s 'https://go.dev/VERSION?m=text' | awk -F 'go' '/^go/ {print $2}')
GO_TAR="go${GO_VERSION}.${OS_TYPE}-${ARCH}.tar.gz"
DOWNLOAD_URL="https://go.dev/dl/${GO_TAR}"

INSTALL_DIR="/usr/local"

echo "🔹 Detected OS: $OS_TYPE"
echo "🔹 Detected Architecture: $ARCH"
echo "🔹 Latest Go Version: $GO_VERSION"
echo "🔹 Downloading: $DOWNLOAD_URL"
echo "🔹 Detected Shell: $SHELL_RC"

# Download Go tarball
curl -LO "$DOWNLOAD_URL"

# Validate the tarball
if ! tar -tzf "$GO_TAR" > /dev/null; then
    echo "❌ Downloaded tarball is corrupted or incorrect."
    exit 1
fi

# Remove any existing Go installation
sudo rm -rf "$INSTALL_DIR/go"

# Ensure the parent directory exists
sudo mkdir -p "$INSTALL_DIR/go"

# Extract Go
sudo tar -C "$INSTALL_DIR" -xzf "$GO_TAR"

# Clean up
rm "$GO_TAR"

# Update PATH
GO_PATH_ENTRY="export PATH=$INSTALL_DIR/go/bin:\$PATH"
if ! grep -qxF "$GO_PATH_ENTRY" "$SHELL_RC"; then
    echo "$GO_PATH_ENTRY" >> "$SHELL_RC"
    echo "✅ PATH updated in $SHELL_RC"
else
    echo "🔹 PATH already exists in $SHELL_RC"
fi

# Apply changes
if [ -f "$SHELL_RC" ]; then
    # shellcheck source=/dev/null
    source "$SHELL_RC"
fi

# Verify
go version

echo "✅ Golang $GO_VERSION installed successfully!"