//! SQL migration runner.
//!
//! Reads migration files from the `migrate/` directory and applies them
//! in lexicographic order using sqlx's built-in migration infrastructure.

use sqlx::PgPool;
use sqlx::migrate::Migrator;
use std::path::Path;

use crate::{ImksError, ImksResult};

/// Run all pending SQL migrations from the `migrate/` directory.
///
/// Migrations are applied in filename order (e.g. `001_…sql` before `002_…sql`).
/// sqlx tracks applied migrations in a `_sqlx_migrations` table so that
/// only new migrations are executed on subsequent runs.
pub async fn run_migrations(pool: &PgPool) -> ImksResult<()> {
    let migrations_dir = Path::new("migrate");

    if !migrations_dir.exists() {
        tracing::warn!("No migrate/ directory found — skipping migrations");
        return Ok(());
    }

    let migrator = Migrator::new(migrations_dir)
        .await
        .map_err(|e| ImksError::Internal(format!("Failed to load migrations: {e}")))?;

    migrator
        .run(pool)
        .await
        .map_err(|e| ImksError::Internal(format!("Migration failed: {e}")))?;

    tracing::info!("Database migrations completed");

    Ok(())
}