vantage-cmd 0.5.1

Local command-execution persistence backend for Vantage, scripted with Rhai — incubating
Documentation 
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//! `CmdTableShell` — owns the typed `Table<Cmd, EmptyEntity>` and exposes
//! it across the `TableShell` boundary.
//!
//! `Value = CborValue` end-to-end, so `list_vista_values` forwards the
//! table's records unchanged. Relations are followed the built-in way:
//! `get_ref` forwards to the wrapped table's [`Table::get_ref_from_row`],
//! which reads the join value out of the parent row and pins the target
//! table with a plain eq-condition — the same path csv / sqlite use.

use async_trait::async_trait;
use ciborium::Value as CborValue;
use indexmap::IndexMap;
use vantage_core::Result;
use vantage_dataset::traits::ReadableValueSet;
use vantage_table::table::Table;
use vantage_types::{EmptyEntity, Record};
use vantage_vista::{
    Column as VistaColumn, Reference as VistaReference, TableShell, Vista, VistaCapabilities,
    VistaMetadata,
};

use crate::cmd::Cmd;
use crate::condition::CmdCondition;
use crate::vista::factory::CmdVistaFactory;

pub struct CmdTableShell {
    table: Table<Cmd, EmptyEntity>,
    capabilities: VistaCapabilities,
    metadata: VistaMetadata,
}

impl CmdTableShell {
    pub(crate) fn new(
        table: Table<Cmd, EmptyEntity>,
        capabilities: VistaCapabilities,
        metadata: VistaMetadata,
    ) -> Self {
        Self {
            table,
            capabilities,
            metadata,
        }
    }
}

#[async_trait]
impl TableShell for CmdTableShell {
    fn columns(&self) -> &IndexMap<String, VistaColumn> {
        &self.metadata.columns
    }

    fn references(&self) -> &IndexMap<String, VistaReference> {
        &self.metadata.references
    }

    fn id_column(&self) -> Option<&str> {
        self.metadata.id_column.as_deref()
    }

    async fn list_vista_values(
        &self,
        _vista: &Vista,
    ) -> Result<IndexMap<String, Record<CborValue>>> {
        self.table.list_values().await
    }

    async fn get_vista_value(
        &self,
        _vista: &Vista,
        id: &String,
    ) -> Result<Option<Record<CborValue>>> {
        let mut data = self.table.list_values().await?;
        Ok(data.shift_remove(id))
    }

    async fn get_vista_some_value(
        &self,
        _vista: &Vista,
    ) -> Result<Option<(String, Record<CborValue>)>> {
        let data = self.table.list_values().await?;
        Ok(data.into_iter().next())
    }

    async fn get_vista_count(&self, _vista: &Vista) -> Result<i64> {
        Ok(self.table.list_values().await?.len() as i64)
    }

    fn add_eq_condition(&mut self, field: &str, value: &CborValue) -> Result<()> {
        self.table
            .add_condition(CmdCondition::eq(field, value.clone()));
        Ok(())
    }

    fn get_ref(&self, relation: &str, row: &Record<CborValue>) -> Result<Vista> {
        // `Cmd::Value` is `CborValue`, so the row passes through unchanged.
        // The table's reference machinery reads the join value out of the
        // parent row and pins the target with a plain eq-condition.
        let target = self.table.get_ref_from_row::<EmptyEntity>(relation, row)?;
        CmdVistaFactory::new(self.table.data_source().clone()).from_table(target)
    }

    fn get_ref_kinds(&self) -> Vec<(String, vantage_vista::ReferenceKind)> {
        self.table.ref_kinds()
    }

    fn capabilities(&self) -> &VistaCapabilities {
        &self.capabilities
    }

    fn driver_name(&self) -> &'static str {
        "cmd"
    }
}