#!/bin/bash
set -e # Exit immediately if a command exits with a non-zero status.

# --- Configuration ---
GITHUB_REPO="kusl/GeminiClient"
INSTALL_DIR="/opt/gemini-client"
# The specific binary name generated by the CI workflow (e.g., gemini-client-linux-x64)
BINARY_BASE_NAME="gemini-client" 
SYMLINK_NAME="gemini-client"
CONFIG_FILE="appsettings.json"

# --- Helper Functions ---
function check_deps() {
    echo "--> Checking for dependencies..."
    local deps=("curl" "jq" "tar")
    local missing=()
    for dep in "${deps[@]}"; do
        if ! command -v "$dep" &> /dev/null; then
            missing+=("$dep")
        fi
    done

    if [ ${#missing[@]} -gt 0 ]; then
        echo "Error: The following dependencies are required: ${missing[*]}"
        echo "Please install them using your package manager."
        echo "  - Fedora/RHEL:   sudo dnf install ${missing[*]}"
        echo "  - Debian/Ubuntu: sudo apt-get update && sudo apt-get install ${missing[*]}"
        exit 1
    fi
}

function detect_arch() {
    echo "--> Detecting system architecture..."
    ARCH=$(uname -m)
    case $ARCH in
        x86_64)
            GH_ARCH="linux-x64"
            ;;
        aarch64)
            GH_ARCH="linux-arm64"
            echo "⚠️  Note: While the project supports ARM64, the current CI pipeline might only publish x64 releases."
            ;;
        armv7l)
            GH_ARCH="linux-arm"
            ;;
        *)
            echo "Error: Unsupported architecture '$ARCH'."
            exit 1
            ;;
    esac
    echo "    Architecture found: $GH_ARCH"
}

# --- Main Script ---

check_deps
detect_arch

# The asset name in GitHub releases (e.g., gemini-client-linux-x64.tar.gz)
ASSET_NAME="${BINARY_BASE_NAME}-${GH_ARCH}.tar.gz"
# The actual executable name inside the tar (e.g., gemini-client-linux-x64)
EXECUTABLE_NAME="${BINARY_BASE_NAME}-${GH_ARCH}"

echo "--> Fetching latest release information from GitHub..."
API_URL="https://api.github.com/repos/$GITHUB_REPO/releases/latest"
RELEASE_JSON=$(curl -s "$API_URL")
DOWNLOAD_URL=$(echo "$RELEASE_JSON" | jq -r ".assets[] | select(.name == \"$ASSET_NAME\") | .browser_download_url")

if [[ -z "$DOWNLOAD_URL" || "$DOWNLOAD_URL" == "null" ]]; then
    echo "Error: Could not find a download URL for asset '$ASSET_NAME' in the latest release."
    echo "This may mean there is no release for your architecture ($GH_ARCH) yet."
    echo "Please check the releases page: https://github.com/$GITHUB_REPO/releases"
    exit 1
fi

VERSION=$(echo "$RELEASE_JSON" | jq -r .tag_name)
echo "    Found version $VERSION at: $DOWNLOAD_URL"

# Create temporary directories
TMP_DIR=$(mktemp -d)
trap 'rm -rf -- "$TMP_DIR"' EXIT

TMP_ARCHIVE="$TMP_DIR/$ASSET_NAME"

echo "--> Downloading..."
curl -L -o "$TMP_ARCHIVE" "$DOWNLOAD_URL"

echo "--> Extracting..."
EXTRACT_DIR="$TMP_DIR/extracted"
mkdir -p "$EXTRACT_DIR"
tar -xzf "$TMP_ARCHIVE" -C "$EXTRACT_DIR"

# --- Configuration Management ---
DEST_CONFIG_PATH="$INSTALL_DIR/$CONFIG_FILE"
TEMP_CONFIG_BACKUP="$TMP_DIR/$CONFIG_FILE.bak"
CONFIG_STRATEGY="none"

# 1. Check if user already has a config
if [ -f "$DEST_CONFIG_PATH" ]; then
    echo "--> Found existing configuration. Preserving it."
    sudo cp "$DEST_CONFIG_PATH" "$TEMP_CONFIG_BACKUP"
    CONFIG_STRATEGY="restore"
else
    # 2. Check if the download included a config (Note: current CI excludes it)
    if [ -f "$EXTRACT_DIR/$CONFIG_FILE" ]; then
        echo "--> Using configuration provided in release."
        CONFIG_STRATEGY="copy_new"
    else
        # 3. Generate default config if missing
        echo "--> No configuration found in release. Generating default $CONFIG_FILE."
        cat <<EOF > "$EXTRACT_DIR/$CONFIG_FILE"
{
    "Logging": {
        "LogLevel": {
            "Default": "Warning",
            "GeminiClient": "Warning",
            "GeminiClientConsole": "Information"
        }
    },
    "GeminiSettings": {
        "ApiKey": "YOUR_GEMINI_API_KEY_HERE",
        "BaseUrl": "https://generativelanguage.googleapis.com/",
        "DefaultModel": "gemini-2.5-flash",
        "StreamingEnabled": true
    }
}
EOF
        CONFIG_STRATEGY="copy_generated"
    fi
fi

echo "--> Installing to $INSTALL_DIR (requires sudo)..."

# Prepare directory
sudo mkdir -p "$INSTALL_DIR"

# Copy executable
sudo cp "$EXTRACT_DIR/$EXECUTABLE_NAME" "$INSTALL_DIR/"

# Handle Config Placement
if [ "$CONFIG_STRATEGY" == "restore" ]; then
    sudo mv "$TEMP_CONFIG_BACKUP" "$DEST_CONFIG_PATH"
elif [ "$CONFIG_STRATEGY" == "copy_generated" ] || [ "$CONFIG_STRATEGY" == "copy_new" ]; then
    sudo cp "$EXTRACT_DIR/$CONFIG_FILE" "$DEST_CONFIG_PATH"
fi

# Set permissions
INSTALLED_EXEC="$INSTALL_DIR/$EXECUTABLE_NAME"
echo "--> Setting executable permissions..."
sudo chmod +x "$INSTALLED_EXEC"
# Ensure config is readable by users
sudo chmod 644 "$DEST_CONFIG_PATH"

# Symlink
echo "--> Updating symbolic link..."
sudo ln -sf "$INSTALLED_EXEC" "/usr/local/bin/$SYMLINK_NAME"

echo ""
echo "✅ Installation complete!"
echo "--------------------------------------------------"
echo "  Executable: $INSTALLED_EXEC"
echo "  Symlink:    /usr/local/bin/$SYMLINK_NAME"
echo "  Config:     $DEST_CONFIG_PATH"
echo "--------------------------------------------------"

if [ "$CONFIG_STRATEGY" == "copy_generated" ]; then
    echo "⚠️  IMPORTANT: A default configuration file was created."
    echo "   You MUST update it with your API Key before running:"
    echo "   sudo nano $DEST_CONFIG_PATH"
    echo ""
    echo "   Get your key here: https://aistudio.google.com/apikey"
elif [ "$CONFIG_STRATEGY" == "restore" ]; then
    echo "   Your previous configuration was preserved."
fi

echo ""
echo "Run the client by typing: $SYMLINK_NAME"