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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183

use std::any::Any;
use std::collections::HashMap;

use crate::expression::Expression;

pub enum StatementKind {
    Select,
    Where,
    Having,
    Limit,
    Offset,
    OrderBy,
    GroupBy,
    AggregateFunction,
    GlobalVariable,
}

pub trait Statement {
    fn kind(&self) -> StatementKind;
    fn as_any(&self) -> &dyn Any;
}

pub enum Query {
    Select(GQLQuery),
    GlobalVariableDeclaration(GlobalVariableStatement),
    Describe(DescribeStatement),
    ShowTables,
}

pub struct GQLQuery {
    pub statements: HashMap<&'static str, Box<dyn Statement>>,
    pub has_aggregation_function: bool,
    pub has_group_by_statement: bool,
    pub hidden_selections: Vec<String>,
}

pub struct SelectStatement {
    pub table_name: String,
    pub fields_names: Vec<String>,
    pub fields_values: Vec<Box<dyn Expression>>,
    pub alias_table: HashMap<String, String>,
    pub is_distinct: bool,
}

impl Statement for SelectStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::Select
    }
}

pub struct WhereStatement {
    pub condition: Box<dyn Expression>,
}

impl Statement for WhereStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::Where
    }
}

pub struct HavingStatement {
    pub condition: Box<dyn Expression>,
}

impl Statement for HavingStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::Having
    }
}

pub struct LimitStatement {
    pub count: usize,
}

impl Statement for LimitStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::Limit
    }
}

pub struct OffsetStatement {
    pub count: usize,
}

impl Statement for OffsetStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::Offset
    }
}

#[derive(PartialEq)]
pub enum SortingOrder {
    Ascending,
    Descending,
}

pub struct OrderByStatement {
    pub arguments: Vec<Box<dyn Expression>>,
    pub sorting_orders: Vec<SortingOrder>,
}

impl Statement for OrderByStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::OrderBy
    }
}

pub struct GroupByStatement {
    pub field_name: String,
}

impl Statement for GroupByStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::GroupBy
    }
}

pub enum AggregateValue {
    Expression(Box<dyn Expression>),
    Function(String, String),
}

pub struct AggregationsStatement {
    pub aggregations: HashMap<String, AggregateValue>,
}

impl Statement for AggregationsStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::AggregateFunction
    }
}

pub struct GlobalVariableStatement {
    pub name: String,
    pub value: Box<dyn Expression>,
}

impl Statement for GlobalVariableStatement {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn kind(&self) -> StatementKind {
        StatementKind::GlobalVariable
    }
}

#[derive(Debug)]
pub struct DescribeStatement {
    pub table_name: String,
}