schema-sync 1.0.0

//! Developer: s4gor
//! Github: https://github.com/s4gor
//!
//! Dry-run mode example
//!
//! This example shows how to use schema-sync in dry-run mode
//! to preview changes without applying them.

use schema_sync::prelude::*;

/// Example: Preview schema changes without applying
#[tokio::main]
async fn main() -> Result<()> {
    println!("Schema Sync - Dry-Run Mode Example");
    println!("===================================");
    println!();
    
    // Example tenant
    let _tenant = TenantContext::new("tenant_123");
    
    // Example of dry-run usage:
    /*
    let adapter = PostgresAdapter::new("postgresql://localhost/db").await?;
    let planner = DefaultPlanner::new();
    let executor = DefaultExecutor::new();
    let diff_calculator = DefaultDiffCalculator::new();
    
    let engine = Engine::from_adapter(
        Box::new(adapter),
        Box::new(planner),
        Box::new(executor),
        Box::new(diff_calculator),
        None,
    );
    
    // Get target schema (from snapshot store or provided)
    let target = get_target_snapshot().await?;
    
    // Dry-run: execute=false
    let result = engine.sync_tenant(&tenant, Some(&target), false).await?;
    
    // Print diff in human-readable format
    print_diff(&result.diff);
    
    if !result.diff.is_empty() {
        println!("\nWould apply {} changes", result.diff.change_count());
    } else {
        println!("\nNo changes needed - schemas are in sync");
    }
    */
    
    Ok(())
}

fn print_diff(_diff: &SchemaDiff) {
    // In a real implementation, this would format the diff
    // in a human-readable way
    println!("Diff preview:");
    println!("  - Tables added: []");
    println!("  - Tables removed: []");
    println!("  - Tables modified: []");
}

async fn get_target_snapshot() -> Result<SchemaSnapshot> {
    // In a real implementation, this would load from snapshot store
    // or be provided by the user
    Err(Error::Snapshot("Not implemented in example".to_string()))
}