1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161

pub use super::vec_mapper::Iter;
use super::{StorageClearable, StorageMapper, VecMapper};
use crate::{
    abi::{TypeAbi, TypeDescriptionContainer, TypeName},
    api::{EndpointFinishApi, ErrorApi, ManagedTypeApi, StorageReadApi, StorageWriteApi},
    finish_all,
    storage::StorageKey,
    storage_clear, storage_get, storage_set,
    types::MultiResultVec,
    EndpointResult,
};
use dharitri_codec::{NestedDecode, NestedEncode, TopDecode, TopEncode};

const ITEM_INDEX: &[u8] = b".index";
const NULL_ENTRY: usize = 0;

pub struct UnorderedSetMapper<SA, T>
where
    SA: StorageReadApi + StorageWriteApi + ManagedTypeApi + ErrorApi + Clone + 'static,
    T: TopEncode + TopDecode + NestedEncode + NestedDecode + 'static,
{
    api: SA,
    base_key: StorageKey<SA>,
    vec_mapper: VecMapper<SA, T>,
}

impl<SA, T> StorageMapper<SA> for UnorderedSetMapper<SA, T>
where
    SA: StorageReadApi + StorageWriteApi + ManagedTypeApi + ErrorApi + Clone + 'static,
    T: TopEncode + TopDecode + NestedEncode + NestedDecode,
{
    fn new(api: SA, base_key: StorageKey<SA>) -> Self {
        UnorderedSetMapper {
            api: api.clone(),
            base_key: base_key.clone(),
            vec_mapper: VecMapper::<SA, T>::new(api, base_key),
        }
    }
}

impl<SA, T> StorageClearable for UnorderedSetMapper<SA, T>
where
    SA: StorageReadApi + StorageWriteApi + ManagedTypeApi + ErrorApi + Clone + 'static,
    T: TopEncode + TopDecode + NestedEncode + NestedDecode,
{
    fn clear(&mut self) {
        for value in self.vec_mapper.iter() {
            self.clear_index(&value);
        }
        self.vec_mapper.clear();
    }
}

impl<SA, T> UnorderedSetMapper<SA, T>
where
    SA: StorageReadApi + StorageWriteApi + ManagedTypeApi + ErrorApi + Clone + 'static,
    T: TopEncode + TopDecode + NestedEncode + NestedDecode,
{
    fn item_index_key(&self, value: &T) -> StorageKey<SA> {
        let mut item_key = self.base_key.clone();
        item_key.append_bytes(ITEM_INDEX);
        item_key.append_item(value);
        item_key
    }

    pub fn get_index(&self, value: &T) -> usize {
        storage_get(self.api.clone(), &self.item_index_key(value))
    }

    fn set_index(&self, value: &T, index: usize) {
        storage_set(self.api.clone(), &self.item_index_key(value), &index);
    }

    fn clear_index(&self, value: &T) {
        storage_clear(self.api.clone(), &self.item_index_key(value));
    }

    /// Returns `true` if the set contains no elements.
    pub fn is_empty(&self) -> bool {
        self.vec_mapper.is_empty()
    }

    /// Returns the number of elements in the set.
    pub fn len(&self) -> usize {
        self.vec_mapper.len()
    }

    /// Returns `true` if the set contains a value.
    pub fn contains(&self, value: &T) -> bool {
        self.get_index(value) != NULL_ENTRY
    }

    /// Adds a value to the set.
    ///
    /// If the set did not have this value present, `true` is returned.
    ///
    /// If the set did have this value present, `false` is returned.
    pub fn insert(&mut self, value: T) -> bool {
        if self.contains(&value) {
            return false;
        }
        self.vec_mapper.push(&value);
        self.set_index(&value, self.len());
        true
    }

    /// Removes a value from the set. Returns whether the value was
    /// present in the set.
    pub fn swap_remove(&mut self, value: &T) -> bool {
        let index = self.get_index(value);
        if index == NULL_ENTRY {
            return false;
        }
        if let Some(last_item) = self.vec_mapper.swap_remove_and_get_old_last(index) {
            self.set_index(&last_item, index);
        }
        self.clear_index(value);
        true
    }

    /// An iterator visiting all elements in arbitrary order.
    /// The iterator element type is `&'a T`.
    pub fn iter(&self) -> Iter<SA, T> {
        self.vec_mapper.iter()
    }
}

/// Behaves like a MultiResultVec when an endpoint result.
impl<SA, T> EndpointResult for UnorderedSetMapper<SA, T>
where
    SA: StorageReadApi + StorageWriteApi + ManagedTypeApi + ErrorApi + Clone + 'static,
    T: TopEncode + TopDecode + NestedEncode + NestedDecode + EndpointResult,
{
    type DecodeAs = MultiResultVec<T::DecodeAs>;

    fn finish<FA>(&self, api: FA)
    where
        FA: ManagedTypeApi + EndpointFinishApi + Clone + 'static,
    {
        finish_all(api, self.iter());
    }
}

/// Behaves like a MultiResultVec when an endpoint result.
impl<SA, T> TypeAbi for UnorderedSetMapper<SA, T>
where
    SA: StorageReadApi + StorageWriteApi + ManagedTypeApi + ErrorApi + Clone + 'static,
    T: TopEncode + TopDecode + NestedEncode + NestedDecode + TypeAbi,
{
    fn type_name() -> TypeName {
        crate::types::MultiResultVec::<T>::type_name()
    }

    fn provide_type_descriptions<TDC: TypeDescriptionContainer>(accumulator: &mut TDC) {
        T::provide_type_descriptions(accumulator);
    }

    fn is_multi_arg_or_result() -> bool {
        true
    }
}