drizzle-postgres 0.2.0

#[cfg(not(feature = "std"))]
use crate::prelude::*;
use crate::traits::PostgresTable;
use crate::values::PostgresValue;
use drizzle_core::{SQL, SQLTableInfo, ToSQL, Token, helpers, traits::SQLModel};

// Re-export core helpers with PostgresValue type for convenience
pub(crate) use helpers::{
    delete, except, except_all, from, group_by_expr, having, intersect, intersect_all, limit,
    offset, order_by, select, select_distinct, set, union, union_all, update, r#where,
};

// Re-export Join from core
pub use drizzle_core::Join;

/// A table-like source accepted by an explicit JOIN tuple.
#[doc(hidden)]
pub trait JoinSource<'a>: join_source_private::Sealed {
    type JoinedTable;

    fn into_join_source_sql(self) -> SQL<'a, PostgresValue<'a>>;
}

mod join_source_private {
    pub trait Sealed {}
}

impl<'a, Table> join_source_private::Sealed for Table where Table: PostgresTable<'a> {}

impl<'a, Name, Projection, Query> join_source_private::Sealed
    for drizzle_core::Derived<'a, PostgresValue<'a>, Name, Projection, Query>
where
    Name: drizzle_core::Tag,
    Projection: drizzle_core::DerivedProjection<Name>,
    Query: ToSQL<'a, PostgresValue<'a>>,
{
}

impl<'a, Table> JoinSource<'a> for Table
where
    Table: PostgresTable<'a>,
{
    type JoinedTable = Table;

    fn into_join_source_sql(self) -> SQL<'a, PostgresValue<'a>> {
        self.into_sql()
    }
}

impl<'a, Name, Projection, Query> JoinSource<'a>
    for drizzle_core::Derived<'a, PostgresValue<'a>, Name, Projection, Query>
where
    Name: drizzle_core::Tag,
    Projection: drizzle_core::DerivedProjection<Name>,
    Query: ToSQL<'a, PostgresValue<'a>>,
{
    type JoinedTable = Self;

    fn into_join_source_sql(self) -> SQL<'a, PostgresValue<'a>> {
        self.into_sql()
    }
}

/// A source or legacy tuple accepted by [`crate::builder::SelectBuilder::cross_join`].
///
/// A bare source renders `CROSS JOIN`. The legacy `(source, predicate)`
/// form renders the equivalent portable `INNER JOIN ... ON ...`, because
/// PostgreSQL does not allow an `ON` clause after `CROSS JOIN`.
#[doc(hidden)]
pub trait CrossJoinArg<'a, FromTable>: cross_join_arg_private::Sealed {
    type JoinedTable;

    fn into_cross_join_sql(self) -> SQL<'a, PostgresValue<'a>>;
}

mod cross_join_arg_private {
    pub trait Sealed {}

    impl<'a, Source> Sealed for Source where Source: super::JoinSource<'a> {}

    impl<'a, Source, Condition> Sealed for (Source, Condition)
    where
        Source: super::JoinSource<'a>,
        Condition: drizzle_core::ToSQL<'a, crate::values::PostgresValue<'a>>,
    {
    }
}

impl<'a, Source, FromTable> CrossJoinArg<'a, FromTable> for Source
where
    Source: JoinSource<'a>,
{
    type JoinedTable = Source::JoinedTable;

    fn into_cross_join_sql(self) -> SQL<'a, PostgresValue<'a>> {
        Join::new()
            .cross()
            .into_sql()
            .append(self.into_join_source_sql())
    }
}

impl<'a, Source, Condition, FromTable> CrossJoinArg<'a, FromTable> for (Source, Condition)
where
    Source: JoinSource<'a>,
    Condition: ToSQL<'a, PostgresValue<'a>>,
{
    type JoinedTable = Source::JoinedTable;

    fn into_cross_join_sql(self) -> SQL<'a, PostgresValue<'a>> {
        let (source, condition) = self;
        Join::new()
            .inner()
            .into_sql()
            .append(source.into_join_source_sql())
            .push(Token::ON)
            .append(condition.into_sql())
    }
}

drizzle_core::impl_join_arg_trait!(
    table_trait: PostgresTable<'a>,
    table_info_trait: SQLTableInfo,
    condition_trait: ToSQL<'a, PostgresValue<'a>>,
    join_source_trait: JoinSource<'a>,
    value_type: PostgresValue<'a>,
);

// Generate all join helper functions using the shared macro
drizzle_core::impl_join_helpers!(
    table_trait: PostgresTable<'a>,
    condition_trait: ToSQL<'a, PostgresValue<'a>>,
    sql_type: SQL<'a, PostgresValue<'a>>,
);

/// Helper function to create a SELECT DISTINCT ON statement (PostgreSQL-specific)
pub(crate) fn select_distinct_on<'a, On, Columns>(
    on: On,
    columns: Columns,
) -> SQL<'a, PostgresValue<'a>>
where
    On: ToSQL<'a, PostgresValue<'a>>,
    Columns: ToSQL<'a, PostgresValue<'a>>,
{
    SQL::from_iter([Token::SELECT, Token::DISTINCT, Token::ON, Token::LPAREN])
        .append(on.into_sql())
        .push(Token::RPAREN)
        .append(columns.into_sql())
}

//------------------------------------------------------------------------------
// USING clause internal helper (PostgreSQL-specific)
//------------------------------------------------------------------------------

fn join_using_internal<'a, Table>(
    table: Table,
    join: Join,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join.into_sql()
        .append(table.into_sql())
        .push(Token::USING)
        .push(Token::LPAREN)
        .append(columns.into_sql())
        .push(Token::RPAREN)
}

//------------------------------------------------------------------------------
// USING clause versions of JOIN functions (PostgreSQL-specific)
//------------------------------------------------------------------------------

/// Creates a JOIN ... USING clause, matching rows where the named columns are equal.
pub fn join_using<'a, Table>(
    table: Table,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join_using_internal(table, Join::new(), columns)
}

/// Creates an INNER JOIN ... USING clause.
pub fn inner_join_using<'a, Table>(
    table: Table,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join_using_internal(table, Join::new().inner(), columns)
}

/// Creates a LEFT JOIN ... USING clause.
pub fn left_join_using<'a, Table>(
    table: Table,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join_using_internal(table, Join::new().left(), columns)
}

/// Creates a LEFT OUTER JOIN ... USING clause.
pub fn left_outer_join_using<'a, Table>(
    table: Table,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join_using_internal(table, Join::new().left().outer(), columns)
}

/// Creates a RIGHT JOIN ... USING clause.
pub fn right_join_using<'a, Table>(
    table: Table,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join_using_internal(table, Join::new().right(), columns)
}

/// Creates a RIGHT OUTER JOIN ... USING clause.
pub fn right_outer_join_using<'a, Table>(
    table: Table,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join_using_internal(table, Join::new().right().outer(), columns)
}

/// Creates a FULL JOIN ... USING clause.
pub fn full_join_using<'a, Table>(
    table: Table,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join_using_internal(table, Join::new().full(), columns)
}

/// Creates a FULL OUTER JOIN ... USING clause.
pub fn full_outer_join_using<'a, Table>(
    table: Table,
    columns: impl ToSQL<'a, PostgresValue<'a>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    join_using_internal(table, Join::new().full().outer(), columns)
}

// Note: NATURAL JOINs don't use USING clause as they automatically match column names
// CROSS JOIN also doesn't use USING clause as it produces Cartesian product

/// Creates an INSERT INTO statement with the specified table - `PostgreSQL` specific
pub(crate) fn insert<'a, Table>(table: &Table) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    SQL::from_iter([Token::INSERT, Token::INTO]).append(table)
}

/// Creates the rows of an INSERT statement.
///
/// Rows usually set the same columns. A `None` passed to a `with_*` setter
/// leaves that column to its default without changing the row's type, so
/// rows can differ; then every row lists the union of the columns, with
/// `DEFAULT` where it sets none.
pub(crate) fn values<'a, Table, T>(
    rows: impl IntoIterator<Item = Table::Insert<T>>,
) -> SQL<'a, PostgresValue<'a>>
where
    Table: PostgresTable<'a>,
{
    let rows: Vec<_> = rows.into_iter().collect();

    if rows.is_empty() {
        return SQL::from(Token::VALUES);
    }

    let columns_info = rows[0].columns();
    let columns_slice = columns_info.as_ref();
    if rows[1..]
        .iter()
        .any(|row| row.columns().as_ref() != columns_slice)
    {
        let rows_sql = drizzle_core::helpers::insert_values_with_defaults(
            rows.iter()
                .map(|row| (row.columns(), row.values()))
                .collect(),
        );
        if let Some(rows_sql) = rows_sql {
            return rows_sql;
        }
    }

    if columns_slice.is_empty() {
        // `DEFAULT VALUES` inserts one row. A query without columns inserts
        // one all-default row per result row.
        // Raw text, not SELECT/FROM tokens: the renderer expands a bare
        // `SELECT` token followed by `FROM` into a projection.
        return if rows.len() == 1 {
            SQL::from_iter([Token::DEFAULT, Token::VALUES])
        } else {
            SQL::raw("SELECT FROM").append(SQL::func(
                "generate_series",
                SQL::number(1)
                    .push(Token::COMMA)
                    .append(SQL::number(rows.len())),
            ))
        };
    }

    let columns_sql = SQL::columns(columns_slice);
    let mut values_sql = SQL::with_capacity_chunks(rows.len().saturating_mul(4));
    for (idx, row) in rows.iter().enumerate() {
        if idx > 0 {
            values_sql.push_mut(Token::COMMA);
        }
        values_sql.push_mut(Token::LPAREN);
        values_sql.append_mut(row.values());
        values_sql.push_mut(Token::RPAREN);
    }

    columns_sql.parens().push(Token::VALUES).append(values_sql)
}

/// Helper function to create a RETURNING clause - `PostgreSQL` specific
pub(crate) fn returning<'a, 'b, I>(columns: I) -> SQL<'a, PostgresValue<'a>>
where
    I: ToSQL<'a, PostgresValue<'a>>,
{
    let columns = columns.into_sql();
    let columns = if columns.chunks.is_empty() {
        SQL::from(Token::STAR)
    } else {
        columns
    };
    SQL::from(Token::RETURNING).append(columns)
}

//------------------------------------------------------------------------------
// FOR UPDATE/SHARE row locking (PostgreSQL-specific)
//------------------------------------------------------------------------------

/// Helper function to create a FOR UPDATE clause
pub(crate) fn for_update<'a>() -> SQL<'a, PostgresValue<'a>> {
    SQL::from_iter([Token::FOR, Token::UPDATE])
}

/// Helper function to create a FOR SHARE clause
pub(crate) fn for_share<'a>() -> SQL<'a, PostgresValue<'a>> {
    SQL::from_iter([Token::FOR, Token::SHARE])
}

/// Helper function to create a FOR NO KEY UPDATE clause
pub(crate) fn for_no_key_update<'a>() -> SQL<'a, PostgresValue<'a>> {
    SQL::from_iter([Token::FOR, Token::NO, Token::KEY, Token::UPDATE])
}

/// Helper function to create a FOR KEY SHARE clause
pub(crate) fn for_key_share<'a>() -> SQL<'a, PostgresValue<'a>> {
    SQL::from_iter([Token::FOR, Token::KEY, Token::SHARE])
}

/// Helper function to create a FOR UPDATE OF table clause.
/// Uses unqualified table name as required by `PostgreSQL`.
pub(crate) fn for_update_of<'a>(table_name: &str) -> SQL<'a, PostgresValue<'a>> {
    SQL::from_iter([Token::FOR, Token::UPDATE, Token::OF])
        .append(SQL::ident(String::from(table_name)))
}

/// Helper function to create a FOR SHARE OF table clause.
/// Uses unqualified table name as required by `PostgreSQL`.
pub(crate) fn for_share_of<'a>(table_name: &str) -> SQL<'a, PostgresValue<'a>> {
    SQL::from_iter([Token::FOR, Token::SHARE, Token::OF])
        .append(SQL::ident(String::from(table_name)))
}

/// Helper function to add NOWAIT to a FOR clause
pub(crate) fn nowait<'a>() -> SQL<'a, PostgresValue<'a>> {
    SQL::from(Token::NOWAIT)
}

/// Helper function to add SKIP LOCKED to a FOR clause
pub(crate) fn skip_locked<'a>() -> SQL<'a, PostgresValue<'a>> {
    SQL::from_iter([Token::SKIP, Token::LOCKED])
}