use reifydb_core::value::column::{Column, columns::Columns, data::ColumnData};
use reifydb_type::value::{constraint::bytes::MaxBytes, container::utf8::Utf8Container, r#type::Type};
use crate::function::{Function, FunctionCapability, FunctionContext, FunctionInfo, error::FunctionError};
pub struct TextChar {
info: FunctionInfo,
}
impl Default for TextChar {
fn default() -> Self {
Self::new()
}
}
impl TextChar {
pub fn new() -> Self {
Self {
info: FunctionInfo::new("text::char"),
}
}
}
impl Function for TextChar {
fn info(&self) -> &FunctionInfo {
&self.info
}
fn capabilities(&self) -> &[FunctionCapability] {
&[FunctionCapability::Scalar]
}
fn return_type(&self, _input_types: &[Type]) -> Type {
Type::Utf8
}
fn execute(&self, ctx: &FunctionContext, args: &Columns) -> Result<Columns, FunctionError> {
if args.len() != 1 {
return Err(FunctionError::ArityMismatch {
function: ctx.fragment.clone(),
expected: 1,
actual: args.len(),
});
}
let column = &args[0];
let (data, bitvec) = column.data().unwrap_option();
let row_count = data.len();
let result_data = match data {
ColumnData::Int1(c) => {
convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
}
ColumnData::Int2(c) => {
convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
}
ColumnData::Int4(c) => {
convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
}
ColumnData::Int8(c) => {
convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
}
ColumnData::Uint1(c) => {
convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
}
ColumnData::Uint2(c) => {
convert_to_char(row_count, c.data().len(), |i| c.get(i).map(|&v| v as u32))
}
ColumnData::Uint4(c) => convert_to_char(row_count, c.data().len(), |i| c.get(i).copied()),
other => {
return Err(FunctionError::InvalidArgumentType {
function: ctx.fragment.clone(),
argument_index: 0,
expected: vec![Type::Int1, Type::Int2, Type::Int4, Type::Int8],
actual: other.get_type(),
});
}
};
let final_data = match bitvec {
Some(bv) => ColumnData::Option {
inner: Box::new(result_data),
bitvec: bv.clone(),
},
None => result_data,
};
Ok(Columns::new(vec![Column::new(ctx.fragment.clone(), final_data)]))
}
}
fn convert_to_char<F>(row_count: usize, _capacity: usize, get_value: F) -> ColumnData
where
F: Fn(usize) -> Option<u32>,
{
let mut result_data = Vec::with_capacity(row_count);
for i in 0..row_count {
match get_value(i) {
Some(code_point) => {
if let Some(ch) = char::from_u32(code_point) {
result_data.push(ch.to_string());
} else {
result_data.push(String::new());
}
}
None => {
result_data.push(String::new());
}
}
}
ColumnData::Utf8 {
container: Utf8Container::new(result_data),
max_bytes: MaxBytes::MAX,
}
}