const { DataTypes } = require('sequelize');

module.exports = (sequelize) => {
  const Task = sequelize.define('Task', {
    id: {
      type: DataTypes.INTEGER,
      primaryKey: true,
      autoIncrement: true
    },
    uuid: {
      type: DataTypes.UUID,
      allowNull: false,
      unique: true,
      defaultValue: DataTypes.UUIDV4
    },
    name: {
      type: DataTypes.STRING,
      allowNull: false
    },
    description: {
      type: DataTypes.TEXT,
      allowNull: true
    },
    due_date: {
      type: DataTypes.DATE,
      allowNull: true
    },
    today: {
      type: DataTypes.BOOLEAN,
      allowNull: false,
      defaultValue: false
    },
    priority: {
      type: DataTypes.INTEGER,
      allowNull: true,
      defaultValue: 0,
      validate: {
        min: 0,
        max: 2
      }
    },
    status: {
      type: DataTypes.INTEGER,
      allowNull: false,
      defaultValue: 0,
      validate: {
        min: 0,
        max: 4
      }
    },
    note: {
      type: DataTypes.TEXT,
      allowNull: true
    },
    recurrence_type: {
      type: DataTypes.STRING,
      allowNull: false,
      defaultValue: 'none'
    },
    recurrence_interval: {
      type: DataTypes.INTEGER,
      allowNull: true
    },
    recurrence_end_date: {
      type: DataTypes.DATE,
      allowNull: true
    },
    last_generated_date: {
      type: DataTypes.DATE,
      allowNull: true
    },
    recurrence_weekday: {
      type: DataTypes.INTEGER,
      allowNull: true,
      validate: {
        min: 0,
        max: 6
      }
    },
    recurrence_month_day: {
      type: DataTypes.INTEGER,
      allowNull: true,
      validate: {
        min: -1,
        max: 31
      }
    },
    recurrence_week_of_month: {
      type: DataTypes.INTEGER,
      allowNull: true,
      validate: {
        min: 1,
        max: 5
      }
    },
    completion_based: {
      type: DataTypes.BOOLEAN,
      allowNull: false,
      defaultValue: false
    },
    user_id: {
      type: DataTypes.INTEGER,
      allowNull: false,
      references: {
        model: 'users',
        key: 'id'
      }
    },
    project_id: {
      type: DataTypes.INTEGER,
      allowNull: true,
      references: {
        model: 'projects',
        key: 'id'
      }
    },
    recurring_parent_id: {
      type: DataTypes.INTEGER,
      allowNull: true,
      references: {
        model: 'tasks',
        key: 'id'
      }
    },
    completed_at: {
      type: DataTypes.DATE,
      allowNull: true
    }
  }, {
    tableName: 'tasks',
    indexes: [
      {
        fields: ['user_id']
      },
      {
        fields: ['project_id']
      },
      {
        fields: ['recurrence_type']
      },
      {
        fields: ['last_generated_date']
      }
    ]
  });

  // Define associations
  Task.associate = function(models) {
    // Self-referencing association for recurring tasks
    Task.belongsTo(models.Task, {
      as: 'RecurringParent',
      foreignKey: 'recurring_parent_id'
    });
    
    Task.hasMany(models.Task, {
      as: 'RecurringChildren',
      foreignKey: 'recurring_parent_id'
    });
  };

  // Define enum constants
  Task.PRIORITY = {
    LOW: 0,
    MEDIUM: 1,
    HIGH: 2
  };

  Task.STATUS = {
    NOT_STARTED: 0,
    IN_PROGRESS: 1,
    DONE: 2,
    ARCHIVED: 3,
    WAITING: 4
  };

  Task.RECURRENCE_TYPE = {
    NONE: 'none',
    DAILY: 'daily',
    WEEKLY: 'weekly',
    MONTHLY: 'monthly',
    MONTHLY_WEEKDAY: 'monthly_weekday',
    MONTHLY_LAST_DAY: 'monthly_last_day'
  };

  // priority and status
  const getPriorityName = (priorityValue) => {
    const priorities = ['low', 'medium', 'high'];
    return priorities[priorityValue] || 'low';
  };

  const getStatusName = (statusValue) => {
    const statuses = ['not_started', 'in_progress', 'done', 'archived', 'waiting'];
    return statuses[statusValue] || 'not_started';
  };

  const getPriorityValue = (priorityName) => {
    const priorities = { 'low': 0, 'medium': 1, 'high': 2 };
    return priorities[priorityName] !== undefined ? priorities[priorityName] : 0;
  };

  const getStatusValue = (statusName) => {
    const statuses = { 
      'not_started': 0, 
      'in_progress': 1, 
      'done': 2, 
      'archived': 3, 
      'waiting': 4 
    };
    return statuses[statusName] !== undefined ? statuses[statusName] : 0;
  };

  // Attach utility functions to model
  Task.getPriorityName = getPriorityName;
  Task.getStatusName = getStatusName;
  Task.getPriorityValue = getPriorityValue;
  Task.getStatusValue = getStatusValue;

  return Task;
};