// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.

//! There are many types of errors in Deno:
//! - AnyError: a generic wrapper that can encapsulate any type of error.
//! - JsError: a container for the error message and stack trace for exceptions
//!   thrown in JavaScript code. We use this to pretty-print stack traces.
//! - Diagnostic: these are errors that originate in TypeScript's compiler.
//!   They're similar to JsError, in that they have line numbers. But
//!   Diagnostics are compile-time type errors, whereas JsErrors are runtime
//!   exceptions.

use deno_ast::Diagnostic;
use deno_core::error::AnyError;
use deno_graph::source::ResolveError;
use deno_graph::ModuleError;
use deno_graph::ModuleGraphError;
use deno_graph::ResolutionError;
use import_map::ImportMapError;
use std::fmt::Write;

fn get_import_map_error_class(_: &ImportMapError) -> &'static str {
  "URIError"
}

fn get_diagnostic_class(_: &Diagnostic) -> &'static str {
  "SyntaxError"
}

fn get_module_graph_error_class(err: &ModuleGraphError) -> &'static str {
  match err {
    ModuleGraphError::ModuleError(err) => match err {
      ModuleError::LoadingErr(_, _, err) => get_error_class_name(err.as_ref()),
      ModuleError::InvalidTypeAssertion { .. } => "SyntaxError",
      ModuleError::ParseErr(_, diagnostic) => get_diagnostic_class(diagnostic),
      ModuleError::UnsupportedMediaType { .. }
      | ModuleError::UnsupportedImportAttributeType { .. } => "TypeError",
      ModuleError::Missing(_, _)
      | ModuleError::MissingDynamic(_, _)
      | ModuleError::UnknownPackage { .. }
      | ModuleError::UnknownPackageReq { .. } => "NotFound",
    },
    ModuleGraphError::ResolutionError(err)
    | ModuleGraphError::TypesResolutionError(err) => {
      get_resolution_error_class(err)
    }
  }
}

fn get_resolution_error_class(err: &ResolutionError) -> &'static str {
  match err {
    ResolutionError::ResolverError { error, .. } => {
      use ResolveError::*;
      match error.as_ref() {
        Specifier(_) => "TypeError",
        Other(e) => get_error_class_name(e),
      }
    }
    _ => "TypeError",
  }
}

pub fn get_error_class_name(e: &AnyError) -> &'static str {
  deno_runtime::errors::get_error_class_name(e)
    .or_else(|| {
      e.downcast_ref::<ImportMapError>()
        .map(get_import_map_error_class)
    })
    .or_else(|| e.downcast_ref::<Diagnostic>().map(get_diagnostic_class))
    .or_else(|| {
      e.downcast_ref::<ModuleGraphError>()
        .map(get_module_graph_error_class)
    })
    .or_else(|| {
      e.downcast_ref::<ResolutionError>()
        .map(get_resolution_error_class)
    })
    .unwrap_or_else(|| {
      if cfg!(debug) {
        log::warn!(
          "Error '{}' contains boxed error of unknown type:{}",
          e,
          e.chain().fold(String::new(), |mut output, e| {
            let _ = write!(output, "\n  {e:?}");
            output
          })
        );
      }
      "Error"
    })
}