#!/usr/bin/env python3
import os
import json
import logging
import sqlite3
from datetime import datetime
from flask import Flask, request, jsonify, render_template, redirect, url_for
from flask_sqlalchemy import SQLAlchemy
import plotly.express as px
import pandas as pd

# Setup logging
logging.basicConfig(
    level=os.environ.get("LOG_LEVEL", "INFO"),
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
)
logger = logging.getLogger("expense_tracker")

# Load configuration
try:
    with open("/data/options.json", "r") as options_file:
        config = json.load(options_file)
except Exception as e:
    logger.warning(f"Failed to load options.json, using defaults: {e}")
    config = {
        "database_path": "expense_tracker.db",  # Local file in current directory
        "log_level": "info",
    }

# Set log level from config
log_level = getattr(logging, config["log_level"].upper(), logging.INFO)
logger.setLevel(log_level)

# Initialize Flask app
app = Flask(__name__)
app.config["SECRET_KEY"] = os.urandom(24)
app.config["SQLALCHEMY_DATABASE_URI"] = f"sqlite:///{config['database_path']}"
app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False

# Initialize database
db = SQLAlchemy(app)

# Define database models
class Category(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(50), nullable=False, unique=True)
    description = db.Column(db.String(200))
    expenses = db.relationship("Expense", backref="category", lazy=True)

class Expense(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    amount = db.Column(db.Float, nullable=False)
    description = db.Column(db.String(200))
    date = db.Column(db.DateTime, nullable=False, default=datetime.now)
    category_id = db.Column(db.Integer, db.ForeignKey("category.id"), nullable=False)

# Create database tables
with app.app_context():
    db.create_all()
    
    # Add default categories if none exist
    if Category.query.count() == 0:
        default_categories = [
            Category(name="Lebensmittel", description="Ausgaben für Lebensmittel und Getränke"),
            Category(name="Transport", description="Ausgaben für öffentliche Verkehrsmittel, Taxi, etc."),
            Category(name="Freizeit", description="Ausgaben für Unterhaltung, Hobbys, etc."),
            Category(name="Wohnen", description="Miete, Nebenkosten, Reparaturen"),
            Category(name="Gesundheit", description="Medikamente, Arztbesuche"),
            Category(name="Sonstiges", description="Sonstige Ausgaben")
        ]
        for category in default_categories:
            db.session.add(category)
        db.session.commit()
        logger.info("Added default categories")

# Routes
@app.route("/")
def index():
    categories = Category.query.all()
    expenses = Expense.query.order_by(Expense.date.desc()).limit(10).all()
    
    # Calculate total expenses
    total_expenses = db.session.query(db.func.sum(Expense.amount)).scalar() or 0
    
    # Calculate expenses by category
    category_expenses = db.session.query(
        Category.name, db.func.sum(Expense.amount)
    ).join(Expense).group_by(Category.name).all()
    
    # Prepare data for charts
    category_names = [item[0] for item in category_expenses]
    category_amounts = [float(item[1]) for item in category_expenses]
    
    return render_template(
        "index.html",
        categories=categories,
        expenses=expenses,
        total_expenses=total_expenses,
        category_names=json.dumps(category_names),
        category_amounts=json.dumps(category_amounts),
        now=datetime.now()
    )

@app.route("/expenses", methods=["GET", "POST"])
def expenses():
    if request.method == "POST":
        # Add new expense
        amount = float(request.form["amount"])
        description = request.form["description"]
        category_id = int(request.form["category_id"])
        date_str = request.form["date"]
        
        # Parse date from form
        date = datetime.strptime(date_str, "%Y-%m-%d")
        
        # Create new expense
        expense = Expense(
            amount=amount,
            description=description,
            category_id=category_id,
            date=date
        )
        
        db.session.add(expense)
        db.session.commit()
        
        return redirect(url_for("expenses"))
    
    # GET request - show expenses and form
    categories = Category.query.all()
    expenses = Expense.query.order_by(Expense.date.desc()).all()
    
    return render_template(
        "expenses.html",
        categories=categories,
        expenses=expenses,
        today=datetime.now().strftime("%Y-%m-%d")
    )

@app.route("/categories", methods=["GET", "POST"])
def categories():
    if request.method == "POST":
        # Add new category
        name = request.form["name"]
        description = request.form["description"]
        
        # Check if category already exists
        existing = Category.query.filter_by(name=name).first()
        if existing:
            return render_template(
                "categories.html",
                categories=Category.query.all(),
                error="Kategorie existiert bereits"
            )
        
        # Create new category
        category = Category(name=name, description=description)
        db.session.add(category)
        db.session.commit()
        
        return redirect(url_for("categories"))
    
    # GET request - show categories and form
    categories = Category.query.all()
    return render_template("categories.html", categories=categories)

@app.route("/api/expenses", methods=["GET", "POST"])
def api_expenses():
    if request.method == "POST":
        # Add new expense via API
        data = request.json
        
        if not data or "amount" not in data or "category_id" not in data:
            return jsonify({"error": "Invalid data"}), 400
        
        # Create new expense
        expense = Expense(
            amount=float(data["amount"]),
            description=data.get("description", ""),
            category_id=int(data["category_id"]),
            date=datetime.now() if "date" not in data else datetime.fromisoformat(data["date"])
        )
        
        db.session.add(expense)
        db.session.commit()
        
        return jsonify({"id": expense.id, "status": "success"}), 201
    
    # GET request - return expenses as JSON
    expenses = Expense.query.order_by(Expense.date.desc()).all()
    result = []
    
    for expense in expenses:
        result.append({
            "id": expense.id,
            "amount": expense.amount,
            "description": expense.description,
            "date": expense.date.isoformat(),
            "category_id": expense.category_id,
            "category_name": expense.category.name
        })
    
    return jsonify(result)

@app.route("/api/categories", methods=["GET"])
def api_categories():
    categories = Category.query.all()
    result = []
    
    for category in categories:
        result.append({
            "id": category.id,
            "name": category.name,
            "description": category.description
        })
    
    return jsonify(result)

@app.route("/reports")
def reports():
    # Get date range filter
    start_date = request.args.get("start_date")
    end_date = request.args.get("end_date")
    
    query = db.session.query(
        Expense.date,
        Category.name.label("category"),
        Expense.amount
    ).join(Category)
    
    # Apply date filters if provided
    if start_date:
        query = query.filter(Expense.date >= datetime.strptime(start_date, "%Y-%m-%d"))
    if end_date:
        query = query.filter(Expense.date <= datetime.strptime(end_date, "%Y-%m-%d"))
    
    # Execute query and convert to DataFrame
    expenses_data = query.all()
    df = pd.DataFrame(expenses_data, columns=["date", "category", "amount"])
    
    # Generate charts
    if not df.empty:
        # Expenses by category pie chart
        fig_category = px.pie(
            df, 
            values="amount", 
            names="category", 
            title="Ausgaben nach Kategorie"
        )
        category_chart = fig_category.to_html(full_html=False)
        
        # Expenses over time line chart
        df["date"] = pd.to_datetime(df["date"])
        df_by_date = df.groupby([df["date"].dt.date]).sum().reset_index()
        fig_timeline = px.line(
            df_by_date, 
            x="date", 
            y="amount", 
            title="Ausgaben im Zeitverlauf"
        )
        timeline_chart = fig_timeline.to_html(full_html=False)
    else:
        category_chart = "<p>Keine Daten verfügbar</p>"
        timeline_chart = "<p>Keine Daten verfügbar</p>"
    
    return render_template(
        "reports.html",
        category_chart=category_chart,
        timeline_chart=timeline_chart,
        start_date=start_date or "",
        end_date=end_date or ""
    )

if __name__ == "__main__":
    # Start the Flask application
    app.run(host="0.0.0.0", port=8099)