icydb-core 0.69.3

//! Module: db::session::sql::dispatch::lowered
//! Responsibility: module-local ownership and contracts for db::session::sql::dispatch::lowered.
//! Does not own: cross-module orchestration outside this module.
//! Boundary: exposes this module API while keeping implementation details internal.

use crate::{
    db::{
        DbSession, MissingRowPolicy, QueryError,
        executor::{EntityAuthority, execute_sql_delete_projection_for_canister},
        session::sql::{
            SqlDispatchResult,
            projection::{
                SqlProjectionPayload, projection_labels_from_entity_model,
                sql_projection_rows_from_kernel_rows,
            },
            surface::{SqlSurface, session_sql_lane, unsupported_sql_lane_message},
        },
        sql::lowering::{
            LoweredBaseQueryShape, LoweredSelectShape, LoweredSqlCommand, LoweredSqlQuery,
            apply_lowered_select_shape, bind_lowered_sql_delete_query_structural,
        },
    },
    traits::CanisterKind,
    value::Value,
};

type SqlQuerySurfaceRowParts = (Vec<String>, Vec<Vec<Value>>, u32);

impl<C: CanisterKind> DbSession<C> {
    // Execute one lowered SQL SELECT command entirely through the shared
    // structural projection path and keep the result in projection form.
    #[inline(never)]
    fn execute_lowered_sql_projection_core(
        &self,
        select: &LoweredSelectShape,
        authority: EntityAuthority,
    ) -> Result<SqlProjectionPayload, QueryError> {
        let structural = apply_lowered_select_shape(
            crate::db::query::intent::StructuralQuery::new(
                authority.model(),
                MissingRowPolicy::Ignore,
            ),
            select.clone(),
        )
        .map_err(QueryError::from_sql_lowering_error)?;

        self.execute_structural_sql_projection(structural, authority)
    }

    // Execute one lowered SQL SELECT command entirely through the shared
    // structural projection path and package it for the shared dispatch lane.
    #[inline(never)]
    pub(in crate::db::session::sql::dispatch) fn execute_lowered_sql_dispatch_select_core(
        &self,
        select: &LoweredSelectShape,
        authority: EntityAuthority,
    ) -> Result<SqlDispatchResult, QueryError> {
        self.execute_lowered_sql_projection_core(select, authority)
            .map(SqlProjectionPayload::into_dispatch_result)
    }

    // Execute one lowered SQL DELETE command through the shared structural
    // delete projection path.
    fn execute_lowered_sql_dispatch_delete_core(
        &self,
        delete: &LoweredBaseQueryShape,
        authority: EntityAuthority,
    ) -> Result<SqlDispatchResult, QueryError> {
        let structural = bind_lowered_sql_delete_query_structural(
            authority.model(),
            delete.clone(),
            MissingRowPolicy::Ignore,
        );
        let deleted = execute_sql_delete_projection_for_canister(
            &self.db,
            authority,
            structural.build_plan()?,
        )
        .map_err(QueryError::execute)?;
        let (rows, row_count) = deleted.into_parts();
        let rows = sql_projection_rows_from_kernel_rows(rows);

        Ok(SqlProjectionPayload::new(
            projection_labels_from_entity_model(authority.model()),
            rows,
            row_count,
        )
        .into_dispatch_result())
    }

    /// Execute one already-lowered shared SQL query shape for resolved authority.
    #[doc(hidden)]
    pub fn execute_lowered_sql_dispatch_query_for_authority(
        &self,
        lowered: &LoweredSqlCommand,
        authority: EntityAuthority,
    ) -> Result<SqlDispatchResult, QueryError> {
        self.execute_lowered_sql_dispatch_query_core(lowered, authority)
    }

    /// Execute one already-lowered shared SQL `SELECT` shape for resolved authority.
    ///
    /// This narrower boundary exists specifically for generated canister query
    /// surfaces that need row-shaped SQL payloads without retaining the full
    /// typed dispatch enum in the outer query facade.
    #[doc(hidden)]
    pub fn execute_lowered_sql_projection_for_authority(
        &self,
        lowered: &LoweredSqlCommand,
        authority: EntityAuthority,
    ) -> Result<SqlQuerySurfaceRowParts, QueryError> {
        let Some(query) = lowered.query() else {
            return Err(QueryError::unsupported_query(unsupported_sql_lane_message(
                SqlSurface::QueryFrom,
                session_sql_lane(lowered),
            )));
        };

        match query {
            LoweredSqlQuery::Select(select) => self
                .execute_lowered_sql_projection_core(select, authority)
                .map(SqlProjectionPayload::into_parts),
            LoweredSqlQuery::Delete(delete) => self
                .execute_lowered_sql_dispatch_delete_core(delete, authority)
                .and_then(|dispatch| match dispatch {
                    SqlDispatchResult::Projection {
                        columns,
                        rows,
                        row_count,
                    } => Ok((columns, rows, row_count)),
                    SqlDispatchResult::Explain(_)
                    | SqlDispatchResult::Describe(_)
                    | SqlDispatchResult::ShowIndexes(_)
                    | SqlDispatchResult::ShowColumns(_)
                    | SqlDispatchResult::ShowEntities(_) => Err(QueryError::unsupported_query(
                        "generated SQL query dispatch requires row-shaped SELECT or DELETE",
                    )),
                }),
        }
    }

    // Execute one lowered SQL query command through the shared structural core
    // and delegate only true typed DELETE fallback to the caller.
    fn execute_lowered_sql_dispatch_query_core(
        &self,
        lowered: &LoweredSqlCommand,
        authority: EntityAuthority,
    ) -> Result<SqlDispatchResult, QueryError> {
        let Some(query) = lowered.query() else {
            return Err(QueryError::unsupported_query(unsupported_sql_lane_message(
                SqlSurface::QueryFrom,
                session_sql_lane(lowered),
            )));
        };

        match query {
            LoweredSqlQuery::Select(select) => {
                self.execute_lowered_sql_dispatch_select_core(select, authority)
            }
            LoweredSqlQuery::Delete(delete) => {
                self.execute_lowered_sql_dispatch_delete_core(delete, authority)
            }
        }
    }
}