#!/bin/bash
set -euo pipefail  # Fail on errors, undefined vars, and pipeline failures

# Function to handle errors
error_exit() {
    echo "[X] Error: $1" >&2
    exit 1
}

# Check if uv is installed
command -v uv >/dev/null 2>&1 || error_exit "uv is not installed"

# Check write permissions in current directory
if [ ! -w "." ]; then
    error_exit "No write permission in current directory"
fi

# SECTION 1: CHECKING THE USER INPUT AND SANITY CHECKS
echo "[*] Checking the user input and sanity checks"

# If .venv exists, ask the user if they want to remove it
if [ -d ".venv" ]; then
    echo "[*] Directory .venv exists: do you want to remove it? (y/n)"
    read -r answer
    case "${answer,,}" in  # Convert to lowercase
        y|yes) 
            rm -rf .venv || error_exit "Failed to remove .venv directory"
            echo "[OK] Directory .venv removed"
            ;;
        *)
            echo "[X] Directory .venv exists and was not removed: exiting"
            exit 1
            ;;
    esac
else
    echo "[OK] Directory .venv does not exist: we can proceed"
fi

# Checking if the user specified a file to add to the project
# If no argument is passed, add requirements.txt as a default
if [ -z "$1" ]; then
    echo "[*] No file specified: adding requirements.txt as a default"
    FILE="requirements.txt"
# If an argument is passed, add it to the project instead of requirements.txt
else
    echo "[*] File specified: adding $1"
    FILE="$1"
fi
# Also, the specified file should exist
if [ ! -f "$FILE" ]; then
    echo "[X] File $FILE does not exist: exiting"
    exit 1
fi
echo "[OK] File $FILE exists"

echo "[OK] All sanity checks passed"

# SECTION 2: INITIALIZING THE UV PROJECT
echo "[*] Initializing the uv project"

# Create backup with timestamp to avoid conflicts
BACKUP_SUFFIX=".bak.$(date +%Y%m%d%H%M%S)"
if [ -f hello.py ]; then
    echo "[*] File hello.py exists: backing up"
    mv "hello.py" "hello.py${BACKUP_SUFFIX}" || error_exit "Failed to backup hello.py"
fi

# Initialize the uv project with error handling
if ! uv init; then
    error_exit "Failed to initialize uv project"
fi

# Remove the hello.py file (if it exists)
echo "[*] Removing hello.py created by uv init"
rm -rf hello.py || true
# If a hello.py.bak file exists, restore it (use BACKUP_SUFFIX)
if [ -f "hello.py${BACKUP_SUFFIX}" ]; then
    echo "[*] Restoring hello.py from backup"
    mv "hello.py${BACKUP_SUFFIX}" hello.py
fi
echo "[OK] Initialized the uv project"

# SECTION 3: ADDING THE REQUIREMENTS.TXT OR SPECIFIED FILE TO THE PROJECT
echo "[*] Adding $FILE to the project"
uv add -r "$FILE"
echo "[OK] Added $FILE to the project"

echo "[OK] All uv commands passed! You can now run the project with uv run."