#!/bin/bash
set -euo pipefail

# download and install dropshell

# 1. Check prerequisites
# ----------------------------------------------------------------------------- 

if ! command -v curl >/dev/null 2>&1; then
    echo "Error: curl is required but not installed" >&2
    echo "Please install curl: apt-get install curl (Debian/Ubuntu) or yum install curl (RedHat/CentOS)" >&2
    exit 1
fi

# 2. Determine architecture
# ----------------------------------------------------------------------------- 

ARCH=$(uname -m)
case "$ARCH" in
    x86_64|amd64) ARCH="x86_64" ;;
    aarch64|arm64) ARCH="aarch64" ;;
    *)
        echo "Warning: Unsupported architecture: $ARCH" >&2
        echo "Attempting to continue with detected architecture..." >&2
        ;;
esac

TARGET_PATH="${HOME}/.local/bin/dropshell"
TARGET_DIR="$(dirname "${TARGET_PATH}")"

# 3. Backup existing installation
# ----------------------------------------------------------------------------- 

if [ -f "${TARGET_PATH}" ]; then
    BACKUP_PATH="${TARGET_PATH}.backup.$(date +%Y%m%d_%H%M%S)"
    echo "Backing up existing installation to ${BACKUP_PATH}"
    mv "${TARGET_PATH}" "${BACKUP_PATH}"
fi

mkdir -p "${TARGET_DIR}"

# 4. Download with retries
# ----------------------------------------------------------------------------- 

DOWNLOAD_URL="https://getbin.xyz/dropshell:latest-${ARCH}"
TEMP_FILE="${TARGET_PATH}.tmp"
MAX_RETRIES=3
RETRY_DELAY=2

echo "Downloading dropshell for ${ARCH}..."

for i in $(seq 1 $MAX_RETRIES); do
    if curl -L --fail --connect-timeout 10 --max-time 60 \
            -o "${TEMP_FILE}" "${DOWNLOAD_URL}" 2>/dev/null; then
        mv "${TEMP_FILE}" "${TARGET_PATH}"
        break
    else
        if [ $i -eq $MAX_RETRIES ]; then
            echo "Failed to download dropshell after $MAX_RETRIES attempts" >&2
            [ -f "${TEMP_FILE}" ] && rm -f "${TEMP_FILE}"
            
            # Restore backup if available
            if [ -n "${BACKUP_PATH:-}" ] && [ -f "${BACKUP_PATH}" ]; then
                echo "Restoring previous installation from backup"
                mv "${BACKUP_PATH}" "${TARGET_PATH}"
            fi
            exit 1
        fi
        echo "Download failed, retrying in ${RETRY_DELAY} seconds... (attempt $i/$MAX_RETRIES)"
        sleep $RETRY_DELAY
    fi
done

# 5. Verify and set permissions
# ----------------------------------------------------------------------------- 

if [ ! -f "${TARGET_PATH}" ]; then
    echo "Error: Download succeeded but file not found at ${TARGET_PATH}" >&2
    exit 1
fi

# Verify it's a binary (basic check)
if ! file "${TARGET_PATH}" | grep -q "executable\|ELF"; then
    echo "Warning: Downloaded file may not be a valid executable" >&2
fi

chmod +x "${TARGET_PATH}"

# Remove backup on successful installation
[ -n "${BACKUP_PATH:-}" ] && [ -f "${BACKUP_PATH}" ] && rm -f "${BACKUP_PATH}"

echo "dropshell installed successfully to $TARGET_PATH"
echo " "

# 6. Update PATH if needed
# ----------------------------------------------------------------------------- 

if [[ ":$PATH:" != *":${TARGET_DIR}:"* ]]; then
    echo "Note: ${TARGET_DIR} is not in your PATH"
    
    # Check which shell config file to update
    SHELL_RC=""
    if [ -n "${BASH_VERSION:-}" ]; then
        SHELL_RC="${HOME}/.bashrc"
    elif [ -n "${ZSH_VERSION:-}" ]; then
        SHELL_RC="${HOME}/.zshrc"
    fi
    
    if [ -n "$SHELL_RC" ] && [ -f "$SHELL_RC" ]; then
        if ! grep -q "export PATH.*${TARGET_DIR}" "$SHELL_RC"; then
            echo "Consider adding to your $SHELL_RC:"
            echo "  export PATH=\"\$PATH:${TARGET_DIR}\""
        fi
    fi
fi

echo "Please:"
echo "1. run '${TARGET_PATH} edit' to edit the configuration."
echo "2. run '${TARGET_PATH} install' to install dropshell components on this computer."
echo "3. run 'source ~/.bashrc' (or ~/.zshrc) to update PATH for the current shell."