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

echo "🚀 AI-Assisted Development Environment Setup"
echo "=============================================="

# Detect OS
OS="unknown"
case "$(uname -s)" in
    Linux*) OS="linux";;
    Darwin*) OS="macos";;
    CYGWIN*|MINGW*|MSYS*) OS="windows";;
esac

echo "Detected OS: $OS"

# --- 1. Check Python ---
echo ""
echo "📦 Checking Python..."
if ! command -v python3 &> /dev/null; then
    echo "❌ Python 3 not found. Please install Python 3.11+."
    exit 1
fi

PYTHON_VERSION=$(python3 --version | grep -oE '[0-9]+\.[0-9]+')
echo "✓ Python $PYTHON_VERSION found"

# --- 2. Create virtual environment ---
echo ""
echo "🌿 Setting up virtual environment..."
if [ ! -d ".venv" ]; then
    python3 -m venv .venv
    echo "✓ Created .venv/"
else
    echo "✓ .venv/ already exists"
fi

source .venv/bin/activate

# --- 3. Install Python dependencies ---
echo ""
echo "📥 Installing Python dependencies..."
pip install --upgrade pip

# Core
pip install fastapi uvicorn pydantic pydantic-settings sqlalchemy pytest pytest-asyncio \
    pytest-mock pytest-cov black ruff mypy httpx factory-boy

# AI Agent libraries (optional but recommended)
pip install smolagents openai

echo "✓ Core dependencies installed"

# --- 4. Check Ollama ---
echo ""
echo "🦙 Checking Ollama..."
if command -v ollama &> /dev/null; then
    echo "✓ Ollama found"
    
    # Check if gemma4:4b is available
    if ollama list | grep -q "gemma4"; then
        echo "✓ Gemma 4 model available"
    else
        echo "⚠ Gemma 4 not found. Pull it with: ollama pull gemma4:4b"
        echo "  (Optional: ollama pull gemma4:9b for stronger reasoning)"
    fi
else
    echo "⚠ Ollama not found. Install from https://ollama.com"
    echo "  After install, run: ollama pull gemma4:4b"
fi

# --- 5. Check Node.js (for MCP servers) ---
echo ""
echo "⬢ Checking Node.js..."
if command -v node &> /dev/null; then
    NODE_VERSION=$(node --version)
    echo "✓ Node.js $NODE_VERSION found"
else
    echo "⚠ Node.js not found. Install for MCP server support."
fi

# --- 6. Check Git ---
echo ""
echo "🔀 Checking Git..."
if [ -d ".git" ]; then
    echo "✓ Git repository initialized"
else
    git init
    echo "✓ Initialized git repository"
fi

# --- 7. Install pre-commit hooks ---
echo ""
echo "🪝 Setting up pre-commit..."
pip install pre-commit
pre-commit install || true

# --- 8. Create .env file ---
echo ""
echo "🔐 Creating .env template..."
if [ ! -f ".env" ]; then
    cat > .env << 'EOF'
# Environment Configuration
# Copy this to .env and fill in real values

APP_NAME="MyApp"
DEBUG=true
DATABASE_URL="sqlite:///./app.db"
SECRET_KEY="change-me-in-production"
ALGORITHM="HS256"
ACCESS_TOKEN_EXPIRE_MINUTES=30

# Hugging Face (optional, for HF model fallback)
HF_TOKEN=""

# Ollama (local)
OLLAMA_BASE_URL="http://localhost:11434"
OLLAMA_MODEL="gemma4:4b"
EOF
    echo "✓ Created .env (edit with your values)"
else
    echo "✓ .env already exists"
fi

# --- 9. Initialize project structure ---
echo ""
echo "📁 Initializing project structure..."
touch src/__init__.py
touch src/core/__init__.py
touch src/api/__init__.py
touch src/services/__init__.py
touch src/utils/__init__.py
touch tests/__init__.py
touch tests/unit/__init__.py
touch tests/integration/__init__.py

echo "✓ Structure initialized"

# --- 10. Create initial files ---
echo ""
echo "📝 Creating starter files..."

# core/config.py
cat > src/core/config.py << 'EOF'
"""Application configuration using pydantic-settings."""

from functools import lru_cache
from pydantic_settings import BaseSettings


class Settings(BaseSettings):
    """Application settings loaded from environment variables."""

    app_name: str = "MyApp"
    debug: bool = False
    database_url: str = "sqlite:///./app.db"
    secret_key: str = "change-me"
    algorithm: str = "HS256"
    access_token_expire_minutes: int = 30

    class Config:
        env_file = ".env"
        env_file_encoding = "utf-8"


@lru_cache
def get_settings() -> Settings:
    """Return cached Settings instance."""
    return Settings()
EOF

# core/models.py
cat > src/core/models.py << 'EOF'
"""SQLAlchemy ORM models."""

from sqlalchemy import Column, Integer, String, DateTime, create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.sql import func

Base = declarative_base()


class BaseModel:
    """Base model with timestamps."""

    id = Column(Integer, primary_key=True, index=True)
    created_at = Column(DateTime(timezone=True), server_default=func.now())
    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
EOF

# core/database.py
cat > src/core/database.py << 'EOF'
"""Database connection and session management."""

from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, Session

from .config import get_settings

settings = get_settings()
engine = create_engine(
    settings.database_url,
    connect_args={"check_same_thread": False} if "sqlite" in settings.database_url else {},
)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


def get_db() -> Session:
    """Yield a database session. Use as FastAPI dependency."""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()
EOF

# utils/exceptions.py
cat > src/utils/exceptions.py << 'EOF'
"""Custom application exceptions."""


class AppException(Exception):
    """Base application exception."""

    def __init__(self, message: str, status_code: int = 500) -> None:
        self.message = message
        self.status_code = status_code
        super().__init__(message)


class ValidationError(AppException):
    """Input validation failed."""

    def __init__(self, message: str) -> None:
        super().__init__(message, status_code=400)


class NotFoundError(AppException):
    """Resource not found."""

    def __init__(self, message: str) -> None:
        super().__init__(message, status_code=404)


class AuthenticationError(AppException):
    """Authentication failed."""

    def __init__(self, message: str = "Authentication failed") -> None:
        super().__init__(message, status_code=401)
EOF

# utils/logger.py
cat > src/utils/logger.py << 'EOF'
"""Structured logging configuration."""

import logging
import sys
from typing import Any


def get_logger(name: str) -> logging.Logger:
    """Return a configured logger."""
    logger = logging.getLogger(name)
    if not logger.handlers:
        handler = logging.StreamHandler(sys.stdout)
        formatter = logging.Formatter(
            "%(asctime)s | %(name)s | %(levelname)s | %(message)s"
        )
        handler.setFormatter(formatter)
        logger.addHandler(handler)
        logger.setLevel(logging.INFO)
    return logger
EOF

# main.py
cat > src/main.py << 'EOF'
"""FastAPI application entry point."""

from fastapi import FastAPI
from contextlib import asynccontextmanager

from .core.config import get_settings
from .utils.logger import get_logger

logger = get_logger(__name__)
settings = get_settings()


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan events."""
    logger.info(f"Starting {settings.app_name}")
    yield
    logger.info(f"Shutting down {settings.app_name}")


app = FastAPI(
    title=settings.app_name,
    debug=settings.debug,
    lifespan=lifespan,
)


@app.get("/health")
async def health_check() -> dict[str, str]:
    """Health check endpoint."""
    return {"status": "ok", "app": settings.app_name}
EOF

# tests/conftest.py
cat > tests/conftest.py << 'EOF'
"""pytest fixtures shared across all tests."""

import pytest
from fastapi.testclient import TestClient

from src.main import app


@pytest.fixture
def client() -> TestClient:
    """Return a FastAPI test client."""
    return TestClient(app)


@pytest.fixture
def sample_user() -> dict:
    """Return sample user data."""
    return {
        "email": "test@example.com",
        "password": "securepassword123",
    }
EOF

# tests/unit/test_main.py
cat > tests/unit/test_main.py << 'EOF'
"""Tests for main application."""

from fastapi.testclient import TestClient

from src.main import app


class TestHealthCheck:
    """Test health check endpoint."""

    def test_health_returns_ok(self, client: TestClient) -> None:
        """Health endpoint should return status ok."""
        response = client.get("/health")
        assert response.status_code == 200
        data = response.json()
        assert data["status"] == "ok"
EOF

echo "✓ Starter files created"

# --- 11. Final instructions ---
echo ""
echo "✅ Setup complete!"
echo ""
echo "Next steps:"
echo "  1. Edit .env with your configuration"
echo "  2. Edit docs/PRD.md with your project requirements"
echo "  3. Start Ollama: ./scripts/start-ollama.sh"
echo "  4. Activate venv: source .venv/bin/activate"
echo "  5. Start coding with AI assistance!"
echo ""
echo "Agent commands:"
echo "  python agents/smolagent_runner.py 'your task here'"
echo "  python agents/multiagent_workflow.py 'your project here'"