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// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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::any::Any;
use std::sync::Arc;

use arrow::array::{ArrayRef, GenericStringArray, OffsetSizeTrait};
use arrow::datatypes::DataType;

use datafusion_common::cast::as_generic_string_array;
use datafusion_common::{exec_err, Result};
use datafusion_expr::TypeSignature::*;
use datafusion_expr::{ColumnarValue, Volatility};
use datafusion_expr::{ScalarUDFImpl, Signature};

use crate::utils::{make_scalar_function, utf8_to_str_type};

#[derive(Debug)]
pub struct ReplaceFunc {
    signature: Signature,
}

impl Default for ReplaceFunc {
    fn default() -> Self {
        Self::new()
    }
}

impl ReplaceFunc {
    pub fn new() -> Self {
        use DataType::*;
        Self {
            signature: Signature::one_of(
                vec![Exact(vec![Utf8, Utf8, Utf8])],
                Volatility::Immutable,
            ),
        }
    }
}

impl ScalarUDFImpl for ReplaceFunc {
    fn as_any(&self) -> &dyn Any {
        self
    }

    fn name(&self) -> &str {
        "replace"
    }

    fn signature(&self) -> &Signature {
        &self.signature
    }

    fn return_type(&self, arg_types: &[DataType]) -> Result<DataType> {
        utf8_to_str_type(&arg_types[0], "replace")
    }

    fn invoke(&self, args: &[ColumnarValue]) -> Result<ColumnarValue> {
        match args[0].data_type() {
            DataType::Utf8 => make_scalar_function(replace::<i32>, vec![])(args),
            DataType::LargeUtf8 => make_scalar_function(replace::<i64>, vec![])(args),
            other => {
                exec_err!("Unsupported data type {other:?} for function replace")
            }
        }
    }
}

/// Replaces all occurrences in string of substring from with substring to.
/// replace('abcdefabcdef', 'cd', 'XX') = 'abXXefabXXef'
fn replace<T: OffsetSizeTrait>(args: &[ArrayRef]) -> Result<ArrayRef> {
    let string_array = as_generic_string_array::<T>(&args[0])?;
    let from_array = as_generic_string_array::<T>(&args[1])?;
    let to_array = as_generic_string_array::<T>(&args[2])?;

    let result = string_array
        .iter()
        .zip(from_array.iter())
        .zip(to_array.iter())
        .map(|((string, from), to)| match (string, from, to) {
            (Some(string), Some(from), Some(to)) => Some(string.replace(from, to)),
            _ => None,
        })
        .collect::<GenericStringArray<T>>();

    Ok(Arc::new(result) as ArrayRef)
}

mod test {}