Documentation
// Copyright 2024 The Drasi Authors.
//
// 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.

use std::sync::Arc;

use drasi_query_ast::ast;

use crate::evaluation::context::QueryVariables;
use crate::evaluation::functions::numeric::Rand;
use crate::evaluation::functions::ScalarFunction;
use crate::evaluation::variable_value::integer::Integer;
use crate::evaluation::variable_value::VariableValue;
use crate::evaluation::{
    ExpressionEvaluationContext, FunctionError, FunctionEvaluationError, InstantQueryClock,
};

#[tokio::test]
async fn rand_too_many_args() {
    let rand = Rand {};
    let binding = QueryVariables::new();
    let context =
        ExpressionEvaluationContext::new(&binding, Arc::new(InstantQueryClock::new(0, 0)));

    let args = vec![VariableValue::Integer(Integer::from(0))];
    let func_expr = ast::FunctionExpression {
        name: Arc::from("rand"),
        args: vec![ast::Expression::UnaryExpression(
            ast::UnaryExpression::Literal(ast::Literal::Null),
        )],
        position_in_query: 10,
    };

    let result = rand.call(&context, &func_expr, args.clone()).await;
    assert!(matches!(
        result.unwrap_err(),
        FunctionError {
            function_name: _,
            error: FunctionEvaluationError::InvalidArgumentCount
        }
    ));
}

#[tokio::test]
async fn rand_is_f64() {
    let rand = Rand {};
    let binding = QueryVariables::new();
    let context =
        ExpressionEvaluationContext::new(&binding, Arc::new(InstantQueryClock::new(0, 0)));

    let args = vec![];
    let func_expr = ast::FunctionExpression {
        name: Arc::from("rand"),
        args: vec![],
        position_in_query: 10,
    };

    let result = rand.call(&context, &func_expr, args.clone()).await.unwrap();
    assert!(result.is_f64());
}

#[tokio::test]
async fn rand_in_range() {
    let rand = Rand {};
    let binding = QueryVariables::new();
    let context =
        ExpressionEvaluationContext::new(&binding, Arc::new(InstantQueryClock::new(0, 0)));

    let args = vec![];
    let func_expr = ast::FunctionExpression {
        name: Arc::from("rand"),
        args: vec![],
        position_in_query: 10,
    };

    let result = rand.call(&context, &func_expr, args.clone()).await.unwrap();
    assert!(result.as_f64().unwrap() >= 0_f64);
    assert!(result.as_f64().unwrap() <= 1_f64);
}