// Copyright 2018 Grove Enterprises LLC
//
// Licensed 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.

#[derive(Debug,Clone,PartialEq)]
pub enum ASTNode {
    SQLIdentifier(String),
    SQLBinaryExpr { left: Box<ASTNode>, op: SQLOperator, right: Box<ASTNode> },
    SQLNested(Box<ASTNode>),
    SQLUnary { operator: SQLOperator, rex: Box<ASTNode> },
    SQLLiteralLong(i64),
    SQLLiteralDouble(f64),
    SQLFunction { id: String, args: Vec<ASTNode> },
    SQLOrderBy { expr: Box<ASTNode>, asc: bool },
    SQLSelect{
        projection: Vec<ASTNode>,
        relation: Option<Box<ASTNode>>,
        selection: Option<Box<ASTNode>>,
        order_by: Option<Vec<ASTNode>>,
        group_by: Option<Vec<ASTNode>>,
        having: Option<Box<ASTNode>>,
        limit: Option<Box<ASTNode>>,
    },
    SQLCreateTable {
        name: String,
        columns: Vec<SQLColumnDef>
    }
}

#[derive(Debug,Clone,PartialEq)]
pub struct SQLColumnDef {
    pub name: String,
    pub data_type: SQLType,
    pub allow_null: bool
}

#[derive(Debug,Clone,PartialEq)]
pub enum SQLType {
    Varchar(usize),
    Float,
    Double,
    Int,
    Long,
}

#[derive(Debug, PartialEq, Clone)]
pub enum SQLOperator {
    Plus,
    Minus,
    Multiply,
    Divide,
    Modulus,
    Gt,
    Lt,
    GtEq,
    LtEq,
    Eq,
    NotEq
}