Files
k-photos/libertas_infra/src/query_builder.rs

113 lines
3.7 KiB
Rust

use libertas_core::{
error::{CoreError, CoreResult},
schema::{ListMediaOptions, SortOrder},
};
use sqlx::QueryBuilder as SqlxQueryBuilder;
pub trait QueryBuilder<T> {
fn apply_options_to_query<'a>(
&self,
query: SqlxQueryBuilder<'a, sqlx::Postgres>,
options: &'a T,
) -> CoreResult<SqlxQueryBuilder<'a, sqlx::Postgres>>;
}
pub struct MediaQueryBuilder {
allowed_sort_columns: Vec<String>,
}
impl MediaQueryBuilder {
pub fn new(allowed_sort_columns: Vec<String>) -> Self {
Self {
allowed_sort_columns,
}
}
fn validate_sort_column<'a>(&self, column: &'a str) -> CoreResult<&'a str> {
if self.allowed_sort_columns.contains(&column.to_string()) {
Ok(column)
} else {
Err(CoreError::Validation(format!(
"Sorting by '{}' is not supported",
column
)))
}
}
pub fn apply_filters_to_query<'a>(
&self,
mut query: SqlxQueryBuilder<'a, sqlx::Postgres>,
options: &'a ListMediaOptions,
) -> CoreResult<(SqlxQueryBuilder<'a, sqlx::Postgres>, i64)> {
let mut metadata_filter_count = 0;
if let Some(filter) = &options.filter {
if let Some(mime) = &filter.mime_type {
query.push(" AND media.mime_type = ");
query.push_bind(mime);
}
if let Some(metadata_filters) = &filter.metadata_filters {
if !metadata_filters.is_empty() {
metadata_filter_count = metadata_filters.len() as i64;
query.push(" JOIN media_metadata mm ON media.id = mm.media_id ");
query.push(" AND ( ");
for (i, filter) in metadata_filters.iter().enumerate() {
if i > 0 {
query.push(" OR ");
}
query.push(" ( mm.tag_name = ");
query.push_bind(&filter.tag_name);
query.push(" AND mm.tag_value = ");
query.push_bind(&filter.tag_value);
query.push(" ) ");
}
query.push(" ) ");
}
}
}
Ok((query, metadata_filter_count))
}
pub fn apply_sorting_to_query<'a>(
&self,
mut query: SqlxQueryBuilder<'a, sqlx::Postgres>,
options: &'a ListMediaOptions,
) -> CoreResult<SqlxQueryBuilder<'a, sqlx::Postgres>> {
if let Some(sort) = &options.sort {
let column = self.validate_sort_column(&sort.sort_by)?;
let direction = match sort.sort_order {
SortOrder::Asc => "ASC",
SortOrder::Desc => "DESC",
};
let nulls_order = if direction == "ASC" {
"NULLS LAST"
} else {
"NULLS FIRST"
};
let order_by_clause = format!("ORDER BY {} {} {}", column, direction, nulls_order);
query.push(order_by_clause);
} else {
query.push(" ORDER BY media.created_at DESC NULLS LAST ");
}
Ok(query)
}
pub fn apply_pagination_to_query<'a>(
&self,
mut query: SqlxQueryBuilder<'a, sqlx::Postgres>,
options: &'a ListMediaOptions,
) -> CoreResult<SqlxQueryBuilder<'a, sqlx::Postgres>> {
if let Some(pagination) = &options.pagination {
let limit = pagination.limit as i64;
let offset = (pagination.page.saturating_sub(1) as i64) * limit;
query.push(" LIMIT ");
query.push_bind(limit);
query.push(" OFFSET ");
query.push_bind(offset);
}
Ok(query)
}
}