//! `PostgresModuleSource` — the Postgres-backed `ModuleSource` impl.
//!
//! Mirrors the structure of [`crate::kv_repo::PostgresKvRepo`] /
//! [`crate::docs_repo::PostgresDocsRepo`]: thin wrapper around a
//! `PgPool` that owns a single statement returning the module by
//! `(cx.app_id, name, kind = 'module')`. The resolver lives in
//! `executor-core` and consumes this trait through the `Services`
//! bundle, so manager-core stays the only crate that touches
//! Postgres.

use async_trait::async_trait;
use chrono::{DateTime, Utc};
use picloud_shared::{ModuleScript, ModuleSource, ModuleSourceError, SdkCallCx};
use sqlx::PgPool;

pub struct PostgresModuleSource {
    pool: PgPool,
}

impl PostgresModuleSource {
    #[must_use]
    pub fn new(pool: PgPool) -> Self {
        Self { pool }
    }
}

#[derive(sqlx::FromRow)]
struct ModuleRow {
    id: uuid::Uuid,
    app_id: uuid::Uuid,
    name: String,
    source: String,
    updated_at: DateTime<Utc>,
}

impl From<ModuleRow> for ModuleScript {
    fn from(r: ModuleRow) -> Self {
        Self {
            script_id: r.id.into(),
            app_id: r.app_id.into(),
            name: r.name,
            source: r.source,
            updated_at: r.updated_at,
        }
    }
}

#[async_trait]
impl ModuleSource for PostgresModuleSource {
    async fn lookup(
        &self,
        cx: &SdkCallCx,
        name: &str,
    ) -> Result<Option<ModuleScript>, ModuleSourceError> {
        // The query is the cross-app isolation boundary: app_id comes
        // from cx (never from the script-passed argument), and the
        // CHECK constraint `kind IN ('endpoint','module')` plus the
        // `kind = 'module'` filter together guarantee endpoint scripts
        // are never importable. The `(app_id, kind)` index from
        // migration 0015 makes this an index scan returning at most
        // one row (per-app uniqueness on `name`).
        let row: Option<ModuleRow> = sqlx::query_as(
            "SELECT id, app_id, name, source, updated_at \
             FROM scripts \
             WHERE app_id = $1 AND kind = 'module' AND name = $2",
        )
        .bind(cx.app_id.into_inner())
        .bind(name)
        .fetch_optional(&self.pool)
        .await
        .map_err(|e| ModuleSourceError::Backend(e.to_string()))?;
        Ok(row.map(Into::into))
    }
}