//
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.
//

package cloudstack

import (
	"fmt"
	"log"
	"strings"

	"github.com/apache/cloudstack-go/v2/cloudstack"
	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
)

func resourceCloudStackStaticNAT() *schema.Resource {
	return &schema.Resource{
		Create: resourceCloudStackStaticNATCreate,
		Exists: resourceCloudStackStaticNATExists,
		Read:   resourceCloudStackStaticNATRead,
		Delete: resourceCloudStackStaticNATDelete,

		Schema: map[string]*schema.Schema{
			"ip_address_id": {
				Type:     schema.TypeString,
				Required: true,
				ForceNew: true,
			},

			"virtual_machine_id": {
				Type:     schema.TypeString,
				Required: true,
				ForceNew: true,
			},

			"vm_guest_ip": {
				Type:     schema.TypeString,
				Optional: true,
				Computed: true,
				ForceNew: true,
			},

			"project": {
				Type:     schema.TypeString,
				Optional: true,
				Computed: true,
				ForceNew: true,
			},
		},
	}
}

func resourceCloudStackStaticNATCreate(d *schema.ResourceData, meta interface{}) error {
	cs := meta.(*cloudstack.CloudStackClient)

	ipaddressid := d.Get("ip_address_id").(string)

	vm, _, err := cs.VirtualMachine.GetVirtualMachineByID(
		d.Get("virtual_machine_id").(string),
		cloudstack.WithProject(d.Get("project").(string)),
	)
	if err != nil {
		return err
	}

	// Create a new parameter struct
	p := cs.NAT.NewEnableStaticNatParams(ipaddressid, vm.Id)

	if vmGuestIP, ok := d.GetOk("vm_guest_ip"); ok {
		p.SetVmguestip(vmGuestIP.(string))

		// Set the network ID based on the guest IP, needed when the public IP address
		// is not associated with any network yet
	NICS:
		for _, nic := range vm.Nic {
			if vmGuestIP.(string) == nic.Ipaddress {
				p.SetNetworkid(nic.Networkid)
				break NICS
			}
			for _, ip := range nic.Secondaryip {
				if vmGuestIP.(string) == ip.Ipaddress {
					p.SetNetworkid(nic.Networkid)
					break NICS
				}
			}
		}
	} else {
		// If no guest IP is configured, use the primary NIC
		p.SetNetworkid(vm.Nic[0].Networkid)
	}

	_, err = cs.NAT.EnableStaticNat(p)
	if err != nil {
		return fmt.Errorf("Error enabling static NAT: %s", err)
	}

	d.SetId(ipaddressid)

	return resourceCloudStackStaticNATRead(d, meta)
}

func resourceCloudStackStaticNATExists(d *schema.ResourceData, meta interface{}) (bool, error) {
	cs := meta.(*cloudstack.CloudStackClient)

	// Get the IP address details
	ip, count, err := cs.Address.GetPublicIpAddressByID(
		d.Id(),
		cloudstack.WithProject(d.Get("project").(string)),
	)
	if err != nil {
		if count == 0 {
			log.Printf("[DEBUG] IP address with ID %s no longer exists", d.Id())
			return false, nil
		}

		return false, err
	}

	return ip.Isstaticnat, nil
}

func resourceCloudStackStaticNATRead(d *schema.ResourceData, meta interface{}) error {
	cs := meta.(*cloudstack.CloudStackClient)

	// Get the IP address details
	ip, count, err := cs.Address.GetPublicIpAddressByID(
		d.Id(),
		cloudstack.WithProject(d.Get("project").(string)),
	)
	if err != nil {
		if count == 0 {
			log.Printf("[DEBUG] IP address with ID %s no longer exists", d.Id())
			d.SetId("")
			return nil
		}

		return err
	}

	if !ip.Isstaticnat {
		log.Printf("[DEBUG] Static NAT is no longer enabled for IP address with ID %s", d.Id())
		d.SetId("")
		return nil
	}

	d.Set("virtual_machine_id", ip.Virtualmachineid)
	d.Set("vm_guest_ip", ip.Vmipaddress)

	setValueOrID(d, "project", ip.Project, ip.Projectid)

	return nil
}

func resourceCloudStackStaticNATDelete(d *schema.ResourceData, meta interface{}) error {
	cs := meta.(*cloudstack.CloudStackClient)

	// Create a new parameter struct
	p := cs.NAT.NewDisableStaticNatParams(d.Id())

	// Disable static NAT
	_, err := cs.NAT.DisableStaticNat(p)
	if err != nil {
		// This is a very poor way to be told the ID does no longer exist :(
		if strings.Contains(err.Error(), fmt.Sprintf(
			"Invalid parameter id value=%s due to incorrect long value format, "+
				"or entity does not exist", d.Id())) {
			return nil
		}

		return fmt.Errorf("Error disabling static NAT: %s", err)
	}

	return nil
}