// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.

//! This module provides file formating utilities using
//! [`dprint`](https://github.com/dsherret/dprint).
//!
//! At the moment it is only consumed using CLI but in
//! the future it can be easily extended to provide
//! the same functions as ops available in JS runtime.

use crate::fs::files_in_subtree;
use crate::op_error::OpError;
use deno_core::ErrBox;
use dprint_plugin_typescript as dprint;
use std::fs;
use std::io::stdin;
use std::io::stdout;
use std::io::Read;
use std::io::Write;
use std::path::Path;
use std::path::PathBuf;

fn is_supported(path: &Path) -> bool {
  if let Some(ext) = path.extension() {
    if ext == "tsx" || ext == "js" || ext == "jsx" {
      true
    } else if ext == "ts" {
      // Currently dprint does not support d.ts files.
      // https://github.com/dsherret/dprint/issues/100
      !path.as_os_str().to_string_lossy().ends_with(".d.ts")
    } else {
      false
    }
  } else {
    false
  }
}

fn get_config() -> dprint::configuration::Configuration {
  use dprint::configuration::*;
  ConfigurationBuilder::new().prettier().build()
}

fn check_source_files(
  config: dprint::configuration::Configuration,
  paths: Vec<PathBuf>,
) -> Result<(), ErrBox> {
  let mut not_formatted_files = vec![];

  for file_path in paths {
    let file_path_str = file_path.to_string_lossy();
    let file_contents = fs::read_to_string(&file_path)?;
    let r = dprint::format_text(&file_path_str, &file_contents, &config);
    match r {
      Ok(None) => {
        // nothing to format, pass
      }
      Ok(Some(formatted_text)) => {
        if formatted_text != file_contents {
          not_formatted_files.push(file_path);
        }
      }
      Err(e) => {
        eprintln!("Error checking: {}", &file_path_str);
        eprintln!("   {}", e);
      }
    }
  }

  if not_formatted_files.is_empty() {
    Ok(())
  } else {
    Err(
      OpError::other(format!(
        "Found {} not formatted {}",
        not_formatted_files.len(),
        files_str(not_formatted_files.len()),
      ))
      .into(),
    )
  }
}

fn files_str(len: usize) -> &'static str {
  if len == 1 {
    "file"
  } else {
    "files"
  }
}

fn format_source_files(
  config: dprint::configuration::Configuration,
  paths: Vec<PathBuf>,
) -> Result<(), ErrBox> {
  let mut not_formatted_files = vec![];

  for file_path in paths {
    let file_path_str = file_path.to_string_lossy();
    let file_contents = fs::read_to_string(&file_path)?;
    let r = dprint::format_text(&file_path_str, &file_contents, &config);
    match r {
      Ok(None) => {
        // nothing to format, pass
      }
      Ok(Some(formatted_text)) => {
        if formatted_text != file_contents {
          println!("{}", file_path_str);
          fs::write(&file_path, formatted_text)?;
          not_formatted_files.push(file_path);
        }
      }
      Err(e) => {
        eprintln!("Error formatting: {}", &file_path_str);
        eprintln!("   {}", e);
      }
    }
  }
  debug!(
    "Formatted {} {}",
    not_formatted_files.len(),
    files_str(not_formatted_files.len()),
  );
  Ok(())
}

/// Format JavaScript/TypeScript files.
///
/// First argument supports globs, and if it is `None`
/// then the current directory is recursively walked.
pub fn format(args: Vec<String>, check: bool) -> Result<(), ErrBox> {
  if args.len() == 1 && args[0] == "-" {
    return format_stdin(check);
  }

  let mut target_files: Vec<PathBuf> = vec![];

  if args.is_empty() {
    target_files.extend(files_in_subtree(
      std::env::current_dir().unwrap(),
      is_supported,
    ));
  } else {
    for arg in args {
      let p = PathBuf::from(arg);
      if p.is_dir() {
        target_files.extend(files_in_subtree(p, is_supported));
      } else {
        target_files.push(p);
      };
    }
  }
  let config = get_config();
  if check {
    check_source_files(config, target_files)?;
  } else {
    format_source_files(config, target_files)?;
  }
  Ok(())
}

/// Format stdin and write result to stdout.
/// Treats input as TypeScript.
/// Compatible with `--check` flag.
fn format_stdin(check: bool) -> Result<(), ErrBox> {
  let mut source = String::new();
  if stdin().read_to_string(&mut source).is_err() {
    return Err(OpError::other("Failed to read from stdin".to_string()).into());
  }
  let config = get_config();

  match dprint::format_text("_stdin.ts", &source, &config) {
    Ok(None) => unreachable!(),
    Ok(Some(formatted_text)) => {
      if check {
        if formatted_text != source {
          println!("Not formatted stdin");
        }
      } else {
        stdout().write_all(formatted_text.as_bytes())?;
      }
    }
    Err(e) => {
      return Err(OpError::other(e).into());
    }
  }
  Ok(())
}

#[test]
fn test_is_supported() {
  assert!(!is_supported(Path::new("tests/subdir/redirects")));
  assert!(!is_supported(Path::new("README.md")));
  assert!(!is_supported(Path::new("lib/typescript.d.ts")));
  assert!(is_supported(Path::new("cli/tests/001_hello.js")));
  assert!(is_supported(Path::new("cli/tests/002_hello.ts")));
  assert!(is_supported(Path::new("foo.jsx")));
  assert!(is_supported(Path::new("foo.tsx")));
}

#[test]
fn check_tests_dir() {
  // Because of cli/tests/error_syntax.js the following should fail but not
  // crash.
  let r = format(vec!["./tests".to_string()], true);
  assert!(r.is_err());
}