// Package netboxapi provides custom functions for the default go-netbox package
// it mostly handles pagination
package netboxapi

import (
	"context"
	"fmt"

	e "git.stinnesbeck.com/nils/errorhandler"
	transport "github.com/go-openapi/runtime/client"
	"github.com/netbox-community/go-netbox/v3/netbox/client"
	"github.com/netbox-community/go-netbox/v3/netbox/client/ipam"
	"github.com/netbox-community/go-netbox/v3/netbox/models"
)

// NetBoxAPI is the type we use to add custom functions
type NetBoxAPI client.NetBoxAPI

// NewNetBoxClient returns a client to NetBox at the given url,
// using the provided token
func NewNetBoxClient(token string, url string) (NetBoxAPI, error) {
	// Construct the API basis and configure authentication
	t := transport.New(url, client.DefaultBasePath, []string{"https"})
	t.DefaultAuthentication = transport.APIKeyAuth(
		"Authorization",
		"header",
		fmt.Sprintf("Token %v", token),
	)

	// create NetBox api variable
	n := client.New(t, nil)

	// create a new variable for our custom functions
	var nb NetBoxAPI = NetBoxAPI(*n)
	return nb, nil
}

// GetPrefixes returns prefixes from the api filtered by the parameter list param
func (nb NetBoxAPI) GetPrefixes(param ipam.IpamPrefixesListParams) ([]*models.Prefix, error) {
	// check if context was set, if not set background
	if param.Context == nil {
		param.Context = context.Background()
	}

	var defaultOffset int64
	var defaultLimit int64 = 50

	// set Offset if not set before
	if param.Limit == nil {
		param.Limit = &defaultLimit
	}

	// set Offset if not set before
	if param.Offset == nil {
		param.Offset = &defaultOffset
	}

	// get prefixes
	prefixes, err := nb.Ipam.IpamPrefixesList(&param, nil)
	if err != nil {
		return nil, e.FormatError("can't get prefixes", err)
	}

	// variable to hold all prefixes to return
	var prefixesToReturn []*models.Prefix

	// append first page of models
	prefixesToReturn = append(prefixesToReturn, prefixes.Payload.Results...)

	// check if there are more prefixes on other pages
	if prefixes.Payload.Next != nil {
		// there are more pages to get

		// calculate new offset
		newOffset := *param.Offset + *param.Limit

		// set new offset
		param.Offset = &newOffset

		// get prefixes from next page
		nextPagePrefixes, err := nb.GetPrefixes(param)
		if err != nil {
			return nil, e.FormatError("can't get prefixes", err)
		}
		// append the results from next page to our prefixes to return
		prefixesToReturn = append(prefixesToReturn, nextPagePrefixes...)
	}

	return prefixesToReturn, nil
}