//! # Rhailib Engine
//!
//! The central Rhai scripting engine for the heromodels ecosystem. This crate provides
//! a unified interface for creating, configuring, and executing Rhai scripts with access
//! to all business domain modules.
//!
//! ## Features
//!
//! - **Unified Engine Creation**: Pre-configured Rhai engine with all DSL modules
//! - **Script Execution Utilities**: Direct evaluation, file-based execution, and AST compilation
//! - **Mock Database System**: Complete testing environment with seeded data
//! - **Feature-Based Architecture**: Modular compilation based on required domains
//!
//! ## Quick Start
//!
//! ```rust
//! use rhailib_engine::{create_heromodels_engine, eval_script};
//!
//! // Create a fully configured engine
//! let engine = create_heromodels_engine();
//!
//! // Execute a business logic script
//! let result = eval_script(&engine, r#"
//!     let company = new_company()
//!         .name("Acme Corp")
//!         .business_type("global");
//!     company.name
//! "#)?;
//!
//! println!("Company name: {}", result.as_string().unwrap());
//! ```
//!
//! ## Available Features
//!
//! - `calendar` (default): Calendar and event management
//! - `finance` (default): Financial accounts, assets, and marketplace
//! - `flow`: Workflow and approval processes
//! - `legal`: Contract and legal document management
//! - `projects`: Project and task management
//! - `biz`: Business operations and entities

use rhai::{Engine, EvalAltResult, Scope, AST};
use rhailib_dsl;
use std::fs;
use std::path::Path;

/// Mock database module for testing and examples
pub mod mock_db;

/// Creates a fully configured Rhai engine with all available DSL modules.
///
/// This function creates a new Rhai engine instance, configures it with appropriate
/// limits and settings, and registers all available business domain modules based
/// on enabled features.
///
/// # Engine Configuration
///
/// The engine is configured with the following limits:
/// - **Expression Depth**: 128 levels for both expressions and functions
/// - **String Size**: 10 MB maximum
/// - **Array Size**: 10,000 elements maximum
/// - **Map Size**: 10,000 key-value pairs maximum
///
/// # Registered Modules
///
/// All enabled DSL modules are automatically registered, including:
/// - Business operations (companies, products, sales, shareholders)
/// - Financial models (accounts, assets, marketplace)
/// - Content management (collections, images, PDFs, books)
/// - Workflow management (flows, steps, signatures)
/// - And more based on enabled features
///
/// # Returns
///
/// A fully configured `Engine` instance ready for script execution.
///
/// # Example
///
/// ```rust
/// use rhailib_engine::create_heromodels_engine;
///
/// let engine = create_heromodels_engine();
///
/// // Engine is now ready to execute scripts with access to all DSL functions
/// let result = engine.eval::<String>(r#"
///     let company = new_company().name("Test Corp");
///     company.name
/// "#).unwrap();
/// assert_eq!(result, "Test Corp");
/// ```
pub fn create_heromodels_engine() -> Engine {
    let mut engine = Engine::new();

    // Configure engine settings
    engine.set_max_expr_depths(128, 128);
    engine.set_max_string_size(10 * 1024 * 1024); // 10 MB
    engine.set_max_array_size(10 * 1024); // 10K elements
    engine.set_max_map_size(10 * 1024); // 10K elements

    // Register all heromodels Rhai modules
    rhailib_dsl::register_dsl_modules(&mut engine);

    engine
}

// /// Register all heromodels Rhai modules with the engine
// pub fn register_all_modules(engine: &mut Engine, db: Arc<OurDB>) {
//     // Register the calendar module if the feature is enabled
//     heromodels::models::access::register_access_rhai_module(engine, db.clone());
//     #[cfg(feature = "calendar")]
//     heromodels::models::calendar::register_calendar_rhai_module(engine, db.clone());
//     heromodels::models::contact::register_contact_rhai_module(engine, db.clone());
//     heromodels::models::library::register_library_rhai_module(engine, db.clone());
//     heromodels::models::circle::register_circle_rhai_module(engine, db.clone());

//     // Register the flow module if the feature is enabled
//     #[cfg(feature = "flow")]
//     heromodels::models::flow::register_flow_rhai_module(engine, db.clone());

//     // // Register the finance module if the feature is enabled
//     // #[cfg(feature = "finance")]
//     // heromodels::models::finance::register_finance_rhai_module(engine, db.clone());

//     // Register the legal module if the feature is enabled
//     #[cfg(feature = "legal")]
//     heromodels::models::legal::register_legal_rhai_module(engine, db.clone());

//     // Register the projects module if the feature is enabled
//     #[cfg(feature = "projects")]
//     heromodels::models::projects::register_projects_rhai_module(engine, db.clone());

//     // Register the biz module if the feature is enabled
//     #[cfg(feature = "biz")]
//     heromodels::models::biz::register_biz_rhai_module(engine, db.clone());

//     println!("Heromodels Rhai modules registered successfully.");
// }

/// Evaluates a Rhai script string and returns the result.
///
/// This function provides a convenient way to execute Rhai script strings directly
/// using the provided engine. It's suitable for one-off script execution or when
/// the script content is dynamically generated.
///
/// # Arguments
///
/// * `engine` - The Rhai engine to use for script execution
/// * `script` - The Rhai script content as a string
///
/// # Returns
///
/// * `Ok(Dynamic)` - The result of script execution
/// * `Err(Box<EvalAltResult>)` - Script compilation or execution error
///
/// # Example
///
/// ```rust
/// use rhailib_engine::{create_heromodels_engine, eval_script};
///
/// let engine = create_heromodels_engine();
/// let result = eval_script(&engine, r#"
///     let x = 42;
///     let y = 8;
///     x + y
/// "#)?;
/// assert_eq!(result.as_int().unwrap(), 50);
/// ```
pub fn eval_script(
    engine: &Engine,
    script: &str,
) -> Result<rhai::Dynamic, Box<rhai::EvalAltResult>> {
    engine.eval::<rhai::Dynamic>(script)
}

/// Evaluates a Rhai script from a file and returns the result.
///
/// This function reads a Rhai script from the filesystem and executes it using
/// the provided engine. It handles file reading errors gracefully and provides
/// meaningful error messages.
///
/// # Arguments
///
/// * `engine` - The Rhai engine to use for script execution
/// * `file_path` - Path to the Rhai script file
///
/// # Returns
///
/// * `Ok(Dynamic)` - The result of script execution
/// * `Err(Box<EvalAltResult>)` - File reading, compilation, or execution error
///
/// # Example
///
/// ```rust
/// use rhailib_engine::{create_heromodels_engine, eval_file};
/// use std::path::Path;
///
/// let engine = create_heromodels_engine();
/// let result = eval_file(&engine, Path::new("scripts/business_logic.rhai"))?;
/// println!("Script result: {:?}", result);
/// ```
///
/// # Error Handling
///
/// File reading errors are converted to Rhai `ErrorSystem` variants with
/// descriptive messages including the file path that failed to load.
pub fn eval_file(
    engine: &Engine,
    file_path: &Path,
) -> Result<rhai::Dynamic, Box<rhai::EvalAltResult>> {
    match fs::read_to_string(file_path) {
        Ok(script_content) => engine.eval::<rhai::Dynamic>(&script_content),
        Err(io_err) => Err(Box::new(EvalAltResult::ErrorSystem(
            format!("Failed to read script file: {}", file_path.display()),
            Box::new(io_err),
        ))),
    }
}

/// Compiles a Rhai script string into an Abstract Syntax Tree (AST).
///
/// This function compiles a Rhai script into an AST that can be executed multiple
/// times with different scopes. This is more efficient than re-parsing the script
/// for each execution when the same script needs to be run repeatedly.
///
/// # Arguments
///
/// * `engine` - The Rhai engine to use for compilation
/// * `script` - The Rhai script content as a string
///
/// # Returns
///
/// * `Ok(AST)` - The compiled Abstract Syntax Tree
/// * `Err(Box<EvalAltResult>)` - Script compilation error
///
/// # Example
///
/// ```rust
/// use rhailib_engine::{create_heromodels_engine, compile_script, run_ast};
/// use rhai::Scope;
///
/// let engine = create_heromodels_engine();
/// let ast = compile_script(&engine, r#"
///     let company = new_company().name(company_name);
///     save_company(company)
/// "#)?;
///
/// // Execute the compiled script multiple times with different variables
/// let mut scope1 = Scope::new();
/// scope1.push("company_name", "Acme Corp");
/// let result1 = run_ast(&engine, &ast, &mut scope1)?;
///
/// let mut scope2 = Scope::new();
/// scope2.push("company_name", "Tech Startup");
/// let result2 = run_ast(&engine, &ast, &mut scope2)?;
/// ```
pub fn compile_script(engine: &Engine, script: &str) -> Result<AST, Box<rhai::EvalAltResult>> {
    Ok(engine.compile(script)?)
}

/// Executes a compiled Rhai script AST with the provided scope.
///
/// This function runs a pre-compiled AST using the provided engine and scope.
/// The scope can contain variables and functions that will be available to
/// the script during execution.
///
/// # Arguments
///
/// * `engine` - The Rhai engine to use for execution
/// * `ast` - The compiled Abstract Syntax Tree to execute
/// * `scope` - Mutable scope containing variables and functions for the script
///
/// # Returns
///
/// * `Ok(Dynamic)` - The result of script execution
/// * `Err(Box<EvalAltResult>)` - Script execution error
///
/// # Example
///
/// ```rust
/// use rhailib_engine::{create_heromodels_engine, compile_script, run_ast};
/// use rhai::Scope;
///
/// let engine = create_heromodels_engine();
/// let ast = compile_script(&engine, "x + y")?;
///
/// let mut scope = Scope::new();
/// scope.push("x", 10_i64);
/// scope.push("y", 32_i64);
///
/// let result = run_ast(&engine, &ast, &mut scope)?;
/// assert_eq!(result.as_int().unwrap(), 42);
/// ```
///
/// # Performance Notes
///
/// Using compiled ASTs is significantly more efficient than re-parsing scripts
/// for repeated execution, especially for complex scripts or when executing
/// the same logic with different input parameters.
pub fn run_ast(
    engine: &Engine,
    ast: &AST,
    scope: &mut Scope,
) -> Result<rhai::Dynamic, Box<rhai::EvalAltResult>> {
    engine.eval_ast_with_scope(scope, ast)
}