// Copyright 2022 Princess B33f Heavy Industries / Dave Shanley
// SPDX-License-Identifier: MIT

package model

import (
    v2 "github.com/pb33f/libopenapi/datamodel/low/v2"
    v3 "github.com/pb33f/libopenapi/datamodel/low/v3"
)

// ItemsChanges represent changes found between a left (original) and right (modified) object. Items is only
// used by Swagger documents.
type ItemsChanges struct {
    *PropertyChanges
    ItemsChanges *ItemsChanges `json:"items,omitempty" yaml:"items,omitempty"`
}

// TotalChanges returns the total number of changes found between two Items objects
// This is a recursive function because Items can contain Items. Be careful!
func (i *ItemsChanges) TotalChanges() int {
    c := i.PropertyChanges.TotalChanges()
    if i.ItemsChanges != nil {
        c += i.ItemsChanges.TotalChanges()
    }
    return c
}

// TotalBreakingChanges returns the total number of breaking changes found between two Swagger Items objects
// This is a recursive method, Items are recursive, be careful!
func (i *ItemsChanges) TotalBreakingChanges() int {
    c := i.PropertyChanges.TotalBreakingChanges()
    if i.ItemsChanges != nil {
        c += i.ItemsChanges.TotalBreakingChanges()
    }
    return c
}

// CompareItems compares two sets of Swagger Item objects. If there are any changes found then a pointer to
// ItemsChanges will be returned, otherwise nil is returned.
//
// It is worth nothing that Items can contain Items. This means recursion is possible and has the potential for
// runaway code if not using the resolver's circular reference checking.
func CompareItems(l, r *v2.Items) *ItemsChanges {

    var changes []*Change
    var props []*PropertyCheck

    ic := new(ItemsChanges)

    // header is identical to items, except for a description.
    props = append(props, addSwaggerHeaderProperties(l, r, &changes)...)
    CheckProperties(props)

    if !l.Items.IsEmpty() && !r.Items.IsEmpty() {
        // inline, check hashes, if they don't match, compare.
        if l.Items.Value.Hash() != r.Items.Value.Hash() {
            // compare.
            ic.ItemsChanges = CompareItems(l.Items.Value, r.Items.Value)
        }

    }
    if l.Items.IsEmpty() && !r.Items.IsEmpty() {
        // added items
        CreateChange(&changes, PropertyAdded, v3.ItemsLabel,
            nil, r.Items.GetValueNode(), true, nil, r.Items.GetValue())
    }
    if !l.Items.IsEmpty() && r.Items.IsEmpty() {
        // removed items
        CreateChange(&changes, PropertyRemoved, v3.ItemsLabel,
            l.Items.GetValueNode(), nil, true, l.Items.GetValue(),
            nil)
    }
    ic.PropertyChanges = NewPropertyChanges(changes)
    if ic.TotalChanges() <= 0 {
        return nil
    }
    return ic
}