const { Instance, InstanceSnapshot, InstanceEvent, Customer, Product, AuditLog } = require('../models');
const { Op } = require('sequelize');

// Get all instances for reseller
const getInstances = async (req, res) => {
  try {
    const { page = 1, limit = 20, status, type, customerId, region } = req.query;
    const resellerId = req.user.resellerId;
    const offset = (page - 1) * limit;

    const where = { resellerId };
    if (status) where.status = status;
    if (type) where.type = type;
    if (customerId) where.customerId = customerId;
    if (region) where.region = region;

    const { count, rows: instances } = await Instance.findAndCountAll({
      where,
      include: [
        {
          model: Customer,
          as: 'customer',
          attributes: ['id', 'companyName', 'contactPerson']
        }
      ],
      limit: parseInt(limit),
      offset: parseInt(offset),
      order: [['createdAt', 'DESC']]
    });

    res.json({
      success: true,
      data: {
        instances,
        pagination: {
          total: count,
          page: parseInt(page),
          pages: Math.ceil(count / limit),
          limit: parseInt(limit)
        }
      }
    });
  } catch (error) {
    console.error('Get instances error:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to fetch instances'
    });
  }
};

// Create new instance
const createInstance = async (req, res) => {
  try {
    const {
      customerId,
      name,
      template,
      size,
      region,
      zone,
      specifications,
      configuration = {},
      tags = []
    } = req.body;
    const resellerId = req.user.resellerId;

    // Verify customer belongs to reseller
    const customer = await Customer.findOne({
      where: { id: customerId, resellerId }
    });

    if (!customer) {
      return res.status(404).json({
        success: false,
        message: 'Customer not found'
      });
    }

    // Create instance record
    const instance = await Instance.create({
      customerId,
      resellerId,
      name,
      template,
      size,
      region,
      zone,
      specifications,
      configuration,
      tags,
      status: 'pending'
    });

    // Log creation event
    await InstanceEvent.create({
      instanceId: instance.id,
      eventType: 'created',
      status: 'completed',
      message: 'Instance created successfully',
      triggeredBy: req.user.id,
      source: 'user',
      startedAt: new Date(),
      completedAt: new Date()
    });

    // Log audit
    await AuditLog.create({
      userId: req.user.id,
      action: 'INSTANCE_CREATED',
      resource: 'instance',
      resourceId: instance.id,
      newValues: instance.toJSON(),
      ipAddress: req.ip,
      userAgent: req.get('User-Agent')
    });

    // TODO: Integrate with Cloudtopiaa IaaS API to actually provision the instance
    // This would be an async operation that updates the instance status

    res.status(201).json({
      success: true,
      message: 'Instance creation initiated',
      data: { instance }
    });
  } catch (error) {
    console.error('Create instance error:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to create instance'
    });
  }
};

// Start instance
const startInstance = async (req, res) => {
  try {
    const { instanceId } = req.params;
    const resellerId = req.user.resellerId;

    const instance = await Instance.findOne({
      where: { id: instanceId, resellerId }
    });

    if (!instance) {
      return res.status(404).json({
        success: false,
        message: 'Instance not found'
      });
    }

    if (!instance.canStart()) {
      return res.status(400).json({
        success: false,
        message: 'Instance cannot be started in current state'
      });
    }

    // Update instance status
    await instance.update({ status: 'starting' });

    // Log event
    await InstanceEvent.create({
      instanceId: instance.id,
      eventType: 'started',
      status: 'in_progress',
      message: 'Starting instance',
      triggeredBy: req.user.id,
      source: 'user',
      startedAt: new Date()
    });

    // TODO: Call Cloudtopiaa IaaS API to start the instance
    // This would be an async operation

    res.json({
      success: true,
      message: 'Instance start initiated',
      data: { instance }
    });
  } catch (error) {
    console.error('Start instance error:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to start instance'
    });
  }
};

// Stop instance
const stopInstance = async (req, res) => {
  try {
    const { instanceId } = req.params;
    const resellerId = req.user.resellerId;

    const instance = await Instance.findOne({
      where: { id: instanceId, resellerId }
    });

    if (!instance) {
      return res.status(404).json({
        success: false,
        message: 'Instance not found'
      });
    }

    if (!instance.canStop()) {
      return res.status(400).json({
        success: false,
        message: 'Instance cannot be stopped in current state'
      });
    }

    // Update instance status
    await instance.update({ status: 'stopping' });

    // Log event
    await InstanceEvent.create({
      instanceId: instance.id,
      eventType: 'stopped',
      status: 'in_progress',
      message: 'Stopping instance',
      triggeredBy: req.user.id,
      source: 'user',
      startedAt: new Date()
    });

    res.json({
      success: true,
      message: 'Instance stop initiated',
      data: { instance }
    });
  } catch (error) {
    console.error('Stop instance error:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to stop instance'
    });
  }
};

// Create snapshot
const createSnapshot = async (req, res) => {
  try {
    const { instanceId } = req.params;
    const { name, description, type = 'manual' } = req.body;
    const resellerId = req.user.resellerId;

    const instance = await Instance.findOne({
      where: { id: instanceId, resellerId }
    });

    if (!instance) {
      return res.status(404).json({
        success: false,
        message: 'Instance not found'
      });
    }

    // Create snapshot record
    const snapshot = await InstanceSnapshot.create({
      instanceId,
      name,
      description,
      type,
      status: 'creating'
    });

    // Log event
    await InstanceEvent.create({
      instanceId: instance.id,
      eventType: 'snapshot_created',
      status: 'in_progress',
      message: `Creating snapshot: ${name}`,
      triggeredBy: req.user.id,
      source: 'user',
      startedAt: new Date()
    });

    res.status(201).json({
      success: true,
      message: 'Snapshot creation initiated',
      data: { snapshot }
    });
  } catch (error) {
    console.error('Create snapshot error:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to create snapshot'
    });
  }
};

// Get instance events
const getInstanceEvents = async (req, res) => {
  try {
    const { instanceId } = req.params;
    const { page = 1, limit = 20 } = req.query;
    const resellerId = req.user.resellerId;
    const offset = (page - 1) * limit;

    // Verify instance belongs to reseller
    const instance = await Instance.findOne({
      where: { id: instanceId, resellerId }
    });

    if (!instance) {
      return res.status(404).json({
        success: false,
        message: 'Instance not found'
      });
    }

    const { count, rows: events } = await InstanceEvent.findAndCountAll({
      where: { instanceId },
      include: [
        {
          model: require('../models').User,
          as: 'user',
          attributes: ['id', 'firstName', 'lastName']
        }
      ],
      limit: parseInt(limit),
      offset: parseInt(offset),
      order: [['createdAt', 'DESC']]
    });

    res.json({
      success: true,
      data: {
        events,
        pagination: {
          total: count,
          page: parseInt(page),
          pages: Math.ceil(count / limit),
          limit: parseInt(limit)
        }
      }
    });
  } catch (error) {
    console.error('Get instance events error:', error);
    res.status(500).json({
      success: false,
      message: 'Failed to fetch instance events'
    });
  }
};

module.exports = {
  getInstances,
  createInstance,
  startInstance,
  stopInstance,
  createSnapshot,
  getInstanceEvents
};