from flask import Flask, render_template, request, jsonify
from tinydb import TinyDB, Query
from datetime import datetime, timedelta

app = Flask(__name__)
db = TinyDB('habits.json')
Habit = Query()

# Helper function to get the current date string
def get_current_date():
    return datetime.now().strftime('%Y-%m-%d')

# Helper function to get a list of dates for the last 30 days
def get_last_30_days():
    dates = []
    for i in range(30):
        date = datetime.now() - timedelta(days=i)
        dates.append(date.strftime('%Y-%m-%d'))
    return dates[::-1] # Reverse to have oldest first

@app.route('/')
def index():
    return render_template('index.html')

@app.route('/habits', methods=['GET'])
def get_habits():
    raw_habits = db.all()
    formatted_habits = []
    last_30_days = get_last_30_days()
    
    for habit_doc in raw_habits:
        # Handle migration from old format (list) to new format (dict)
        completed_dates = habit_doc.get('completed_dates', {})
        if isinstance(completed_dates, list):
            # Convert old format to new format
            new_completed_dates = {}
            for date in completed_dates:
                new_completed_dates[date] = 1
            completed_dates = new_completed_dates
            # Update in database
            db.update({'completed_dates': completed_dates}, doc_ids=[habit_doc.doc_id])
        
        current_habit_data = {
            'id': habit_doc.doc_id,
            'name': habit_doc.get('name'),
            'completed_dates': completed_dates,
            'color': habit_doc.get('color', '#4CAF50'),
            'daily_target': habit_doc.get('daily_target', 1)
        }
        
        completion_history = {}
        for date_str in last_30_days:
            completed_count = completed_dates.get(date_str, 0)
            target_count = current_habit_data['daily_target']
            completion_history[date_str] = {
                'completed': completed_count,
                'target': target_count,
                'is_complete': completed_count >= target_count
            }
        
        current_habit_data['completion_history'] = completion_history
        formatted_habits.append(current_habit_data)
        
    return jsonify(formatted_habits)

@app.route('/habits', methods=['POST'])
def add_habit():
    data = request.json
    name = data.get('name')
    color = data.get('color', '#4CAF50')  # Default green color
    daily_target = data.get('daily_target', 1)  # Default 1x per day
    if not name:
        return jsonify({'error': 'Habit name is required'}), 400
    
    habit_id = db.insert({'name': name, 'completed_dates': {}, 'color': color, 'daily_target': daily_target})
    return jsonify({'id': habit_id, 'name': name, 'completed_dates': {}, 'color': color, 'daily_target': daily_target}), 201

@app.route('/habits/<int:habit_id>/complete', methods=['POST'])
def complete_habit(habit_id):
    date_to_complete = request.json.get('date', get_current_date())
    
    habit = db.get(doc_id=habit_id)
    if not habit:
        return jsonify({'error': 'Habit not found'}), 404
    
    # Handle migration from old format (list) to new format (dict)
    completed_dates = habit.get('completed_dates', {})
    if isinstance(completed_dates, list):
        new_completed_dates = {}
        for date in completed_dates:
            new_completed_dates[date] = 1
        completed_dates = new_completed_dates
    
    # Increment completion count for the date
    current_count = completed_dates.get(date_to_complete, 0)
    completed_dates[date_to_complete] = current_count + 1
    
    db.update({'completed_dates': completed_dates}, doc_ids=[habit_id])
    
    return jsonify({
        'message': f'Habit {habit_id} marked as completed for {date_to_complete}', 
        'completed_dates': completed_dates,
        'current_count': completed_dates[date_to_complete]
    })

@app.route('/habits/<int:habit_id>/uncomplete', methods=['POST'])
def uncomplete_habit(habit_id):
    date_to_uncomplete = request.json.get('date', get_current_date())

    habit = db.get(doc_id=habit_id)
    if not habit:
        return jsonify({'error': 'Habit not found'}), 404
    
    # Handle migration from old format (list) to new format (dict)
    completed_dates = habit.get('completed_dates', {})
    if isinstance(completed_dates, list):
        new_completed_dates = {}
        for date in completed_dates:
            new_completed_dates[date] = 1
        completed_dates = new_completed_dates
    
    # Decrement completion count for the date
    if date_to_uncomplete in completed_dates:
        current_count = completed_dates[date_to_uncomplete]
        if current_count > 1:
            completed_dates[date_to_uncomplete] = current_count - 1
        else:
            del completed_dates[date_to_uncomplete]
    
    db.update({'completed_dates': completed_dates}, doc_ids=[habit_id])
    
    return jsonify({
        'message': f'Habit {habit_id} marked as uncompleted for {date_to_uncomplete}', 
        'completed_dates': completed_dates,
        'current_count': completed_dates.get(date_to_uncomplete, 0)
    })

@app.route('/habits/<int:habit_id>', methods=['PUT'])
def update_habit(habit_id):
    data = request.json
    name = data.get('name')
    color = data.get('color')
    daily_target = data.get('daily_target')
    
    if not name and not color and not daily_target:
        return jsonify({'error': 'Habit name, color, or daily target is required'}), 400
    
    habit = db.get(doc_id=habit_id)
    if not habit:
        return jsonify({'error': 'Habit not found'}), 404
    
    update_data = {}
    if name:
        update_data['name'] = name
    if color:
        update_data['color'] = color
    if daily_target:
        update_data['daily_target'] = int(daily_target)
    
    db.update(update_data, doc_ids=[habit_id])
    return jsonify({'message': f'Habit {habit_id} updated', **update_data})

@app.route('/habits/<int:habit_id>', methods=['DELETE'])
def delete_habit(habit_id):
    habit = db.get(doc_id=habit_id)
    if not habit:
        return jsonify({'error': 'Habit not found'}), 404
    
    db.remove(doc_ids=[habit_id])
    return jsonify({'message': f'Habit {habit_id} deleted'})

if __name__ == '__main__':
    app.run(debug=True)