// Copyright 2018-2021 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_core::error::AnyError;
use deno_core::serde_json;
use deno_core::url;
use deno_core::ModuleResolutionError;
use deno_fetch::reqwest;
use std::env;
use std::error::Error;
use std::io;

fn get_dlopen_error_class(error: &dlopen::Error) -> &'static str {
  use dlopen::Error::*;
  match error {
    NullCharacter(_) => "InvalidData",
    OpeningLibraryError(ref e) => get_io_error_class(e),
    SymbolGettingError(ref e) => get_io_error_class(e),
    AddrNotMatchingDll(ref e) => get_io_error_class(e),
    NullSymbol => "NotFound",
  }
}

fn get_env_var_error_class(error: &env::VarError) -> &'static str {
  use env::VarError::*;
  match error {
    NotPresent => "NotFound",
    NotUnicode(..) => "InvalidData",
  }
}

fn get_io_error_class(error: &io::Error) -> &'static str {
  use io::ErrorKind::*;
  match error.kind() {
    NotFound => "NotFound",
    PermissionDenied => "PermissionDenied",
    ConnectionRefused => "ConnectionRefused",
    ConnectionReset => "ConnectionReset",
    ConnectionAborted => "ConnectionAborted",
    NotConnected => "NotConnected",
    AddrInUse => "AddrInUse",
    AddrNotAvailable => "AddrNotAvailable",
    BrokenPipe => "BrokenPipe",
    AlreadyExists => "AlreadyExists",
    InvalidInput => "TypeError",
    InvalidData => "InvalidData",
    TimedOut => "TimedOut",
    Interrupted => "Interrupted",
    WriteZero => "WriteZero",
    UnexpectedEof => "UnexpectedEof",
    Other => "Error",
    WouldBlock => unreachable!(),
    // Non-exhaustive enum - might add new variants
    // in the future
    _ => unreachable!(),
  }
}

fn get_module_resolution_error_class(
  _: &ModuleResolutionError,
) -> &'static str {
  "URIError"
}

fn get_notify_error_class(error: &notify::Error) -> &'static str {
  use notify::ErrorKind::*;
  match error.kind {
    Generic(_) => "Error",
    Io(ref e) => get_io_error_class(e),
    PathNotFound => "NotFound",
    WatchNotFound => "NotFound",
    InvalidConfig(_) => "InvalidData",
    MaxFilesWatch => "Error",
  }
}

fn get_regex_error_class(error: &regex::Error) -> &'static str {
  use regex::Error::*;
  match error {
    Syntax(_) => "SyntaxError",
    CompiledTooBig(_) => "RangeError",
    _ => "Error",
  }
}

fn get_request_error_class(error: &reqwest::Error) -> &'static str {
  error
    .source()
    .and_then(|inner_err| {
      (inner_err
        .downcast_ref::<io::Error>()
        .map(get_io_error_class))
      .or_else(|| {
        inner_err
          .downcast_ref::<serde_json::error::Error>()
          .map(get_serde_json_error_class)
      })
      .or_else(|| {
        inner_err
          .downcast_ref::<url::ParseError>()
          .map(get_url_parse_error_class)
      })
    })
    .unwrap_or("Http")
}

fn get_serde_json_error_class(
  error: &serde_json::error::Error,
) -> &'static str {
  use deno_core::serde_json::error::*;
  match error.classify() {
    Category::Io => error
      .source()
      .and_then(|e| e.downcast_ref::<io::Error>())
      .map(get_io_error_class)
      .unwrap(),
    Category::Syntax => "SyntaxError",
    Category::Data => "InvalidData",
    Category::Eof => "UnexpectedEof",
  }
}

fn get_url_parse_error_class(_error: &url::ParseError) -> &'static str {
  "URIError"
}

fn get_hyper_error_class(_error: &hyper::Error) -> &'static str {
  "Http"
}

#[cfg(unix)]
fn get_nix_error_class(error: &nix::Error) -> &'static str {
  use nix::errno::Errno::*;
  match error {
    nix::Error::Sys(ECHILD) => "NotFound",
    nix::Error::Sys(EINVAL) => "TypeError",
    nix::Error::Sys(ENOENT) => "NotFound",
    nix::Error::Sys(ENOTTY) => "BadResource",
    nix::Error::Sys(EPERM) => "PermissionDenied",
    nix::Error::Sys(ESRCH) => "NotFound",
    nix::Error::Sys(UnknownErrno) => "Error",
    nix::Error::Sys(_) => "Error",
    nix::Error::InvalidPath => "TypeError",
    nix::Error::InvalidUtf8 => "InvalidData",
    nix::Error::UnsupportedOperation => unreachable!(),
  }
}

pub fn get_error_class_name(e: &AnyError) -> Option<&'static str> {
  deno_core::error::get_custom_error_class(e)
    .or_else(|| deno_webgpu::error::get_error_class_name(e))
    .or_else(|| {
      e.downcast_ref::<dlopen::Error>()
        .map(get_dlopen_error_class)
    })
    .or_else(|| e.downcast_ref::<hyper::Error>().map(get_hyper_error_class))
    .or_else(|| {
      e.downcast_ref::<deno_core::Canceled>().map(|e| {
        let io_err: io::Error = e.to_owned().into();
        get_io_error_class(&io_err)
      })
    })
    .or_else(|| {
      e.downcast_ref::<env::VarError>()
        .map(get_env_var_error_class)
    })
    .or_else(|| e.downcast_ref::<io::Error>().map(get_io_error_class))
    .or_else(|| {
      e.downcast_ref::<ModuleResolutionError>()
        .map(get_module_resolution_error_class)
    })
    .or_else(|| {
      e.downcast_ref::<notify::Error>()
        .map(get_notify_error_class)
    })
    .or_else(|| {
      e.downcast_ref::<reqwest::Error>()
        .map(get_request_error_class)
    })
    .or_else(|| e.downcast_ref::<regex::Error>().map(get_regex_error_class))
    .or_else(|| {
      e.downcast_ref::<serde_json::error::Error>()
        .map(get_serde_json_error_class)
    })
    .or_else(|| {
      e.downcast_ref::<url::ParseError>()
        .map(get_url_parse_error_class)
    })
    .or_else(|| {
      #[cfg(unix)]
      let maybe_get_nix_error_class =
        || e.downcast_ref::<nix::Error>().map(get_nix_error_class);
      #[cfg(not(unix))]
      let maybe_get_nix_error_class = || Option::<&'static str>::None;
      (maybe_get_nix_error_class)()
    })
}