// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.

use std::path::Path;
use std::path::PathBuf;
use std::sync::Arc;

use deno_ast::ModuleSpecifier;
use deno_core::anyhow::bail;
use deno_core::anyhow::Context;
use deno_core::error::AnyError;
use deno_core::resolve_url_or_path;
use log::warn;

use crate::args::CliOptions;
use crate::args::Flags;
use crate::args::FmtOptionsConfig;
use crate::args::VendorFlags;
use crate::proc_state::ProcState;
use crate::tools::fmt::format_json;
use crate::util::fs::canonicalize_path;
use crate::util::fs::resolve_from_cwd;
use crate::util::path::relative_specifier;
use crate::util::path::specifier_to_file_path;

mod analyze;
mod build;
mod import_map;
mod mappings;
mod specifiers;
#[cfg(test)]
mod test;

pub async fn vendor(
  flags: Flags,
  vendor_flags: VendorFlags,
) -> Result<(), AnyError> {
  let mut cli_options = CliOptions::from_flags(flags)?;
  let raw_output_dir = match &vendor_flags.output_path {
    Some(output_path) => output_path.to_owned(),
    None => PathBuf::from("vendor/"),
  };
  let output_dir = resolve_from_cwd(&raw_output_dir)?;
  validate_output_dir(&output_dir, &vendor_flags)?;
  validate_options(&mut cli_options, &output_dir)?;
  let ps = ProcState::from_options(Arc::new(cli_options)).await?;
  let graph = create_graph(&ps, &vendor_flags).await?;
  let vendored_count = build::build(
    graph,
    &ps.parsed_source_cache,
    &output_dir,
    ps.maybe_import_map.as_deref(),
    ps.lockfile.clone(),
    &build::RealVendorEnvironment,
  )?;

  log::info!(
    concat!("Vendored {} {} into {} directory.",),
    vendored_count,
    if vendored_count == 1 {
      "module"
    } else {
      "modules"
    },
    raw_output_dir.display(),
  );
  if vendored_count > 0 {
    let import_map_path = raw_output_dir.join("import_map.json");
    if maybe_update_config_file(&output_dir, &ps) {
      log::info!(
        concat!(
          "\nUpdated your local Deno configuration file with a reference to the ",
          "new vendored import map at {}. Invoking Deno subcommands will now ",
          "automatically resolve using the vendored modules. You may override ",
          "this by providing the `--import-map <other-import-map>` flag or by ",
          "manually editing your Deno configuration file.",
        ),
        import_map_path.display(),
      );
    } else {
      log::info!(
        concat!(
          "\nTo use vendored modules, specify the `--import-map {}` flag when ",
          r#"invoking Deno subcommands or add an `"importMap": "<path_to_vendored_import_map>"` "#,
          "entry to a deno.json file.",
        ),
        import_map_path.display(),
      );
    }
  }

  Ok(())
}

fn validate_output_dir(
  output_dir: &Path,
  flags: &VendorFlags,
) -> Result<(), AnyError> {
  if !flags.force && !is_dir_empty(output_dir)? {
    bail!(concat!(
      "Output directory was not empty. Please specify an empty directory or use ",
      "--force to ignore this error and potentially overwrite its contents.",
    ));
  }
  Ok(())
}

fn validate_options(
  options: &mut CliOptions,
  output_dir: &Path,
) -> Result<(), AnyError> {
  // check the import map
  if let Some(import_map_path) = options
    .resolve_import_map_specifier()?
    .and_then(|p| specifier_to_file_path(&p).ok())
    .and_then(|p| canonicalize_path(&p).ok())
  {
    // make the output directory in order to canonicalize it for the check below
    std::fs::create_dir_all(output_dir)?;
    let output_dir = canonicalize_path(output_dir).with_context(|| {
      format!("Failed to canonicalize: {}", output_dir.display())
    })?;

    if import_map_path.starts_with(output_dir) {
      // canonicalize to make the test for this pass on the CI
      let cwd = canonicalize_path(&std::env::current_dir()?)?;
      // We don't allow using the output directory to help generate the
      // new state because this may lead to cryptic error messages.
      log::warn!(
        concat!(
          "Ignoring import map. Specifying an import map file ({}) in the ",
          "deno vendor output directory is not supported. If you wish to use ",
          "an import map while vendoring, please specify one located outside ",
          "this directory."
        ),
        import_map_path
          .strip_prefix(&cwd)
          .unwrap_or(&import_map_path)
          .display()
          .to_string(),
      );

      // don't use an import map in the config
      options.set_import_map_specifier(None);
    }
  }

  Ok(())
}

fn maybe_update_config_file(output_dir: &Path, ps: &ProcState) -> bool {
  assert!(output_dir.is_absolute());
  let config_file_specifier = match ps.options.maybe_config_file_specifier() {
    Some(f) => f,
    None => return false,
  };
  let fmt_config = ps
    .options
    .to_fmt_config()
    .unwrap_or_default()
    .unwrap_or_default();
  let result = update_config_file(
    &config_file_specifier,
    &ModuleSpecifier::from_file_path(output_dir.join("import_map.json"))
      .unwrap(),
    &fmt_config.options,
  );
  match result {
    Ok(()) => true,
    Err(err) => {
      warn!("Error updating config file. {:#}", err);
      false
    }
  }
}

fn update_config_file(
  config_specifier: &ModuleSpecifier,
  import_map_specifier: &ModuleSpecifier,
  fmt_options: &FmtOptionsConfig,
) -> Result<(), AnyError> {
  if config_specifier.scheme() != "file" {
    return Ok(());
  }

  let config_path = specifier_to_file_path(config_specifier)?;
  let config_text = std::fs::read_to_string(&config_path)?;
  let relative_text =
    match relative_specifier(config_specifier, import_map_specifier) {
      Some(text) => text,
      None => return Ok(()), // ignore
    };
  if let Some(new_text) =
    update_config_text(&config_text, &relative_text, fmt_options)
  {
    std::fs::write(config_path, new_text)?;
  }

  Ok(())
}

fn update_config_text(
  text: &str,
  import_map_specifier: &str,
  fmt_options: &FmtOptionsConfig,
) -> Option<String> {
  use jsonc_parser::ast::ObjectProp;
  use jsonc_parser::ast::Value;
  let ast =
    jsonc_parser::parse_to_ast(text, &Default::default(), &Default::default())
      .ok()?;
  let obj = match ast.value {
    Some(Value::Object(obj)) => obj,
    _ => return None, // shouldn't happen, so ignore
  };
  let import_map_specifier = import_map_specifier.replace('\"', "\\\"");

  match obj.get("importMap") {
    Some(ObjectProp {
      value: Value::StringLit(lit),
      ..
    }) => Some(format!(
      "{}{}{}",
      &text[..lit.range.start + 1],
      import_map_specifier,
      &text[lit.range.end - 1..],
    )),
    None => {
      // insert it crudely at a position that won't cause any issues
      // with comments and format after to make it look nice
      let insert_position = obj.range.end - 1;
      let insert_text = format!(
        r#"{}"importMap": "{}""#,
        if obj.properties.is_empty() { "" } else { "," },
        import_map_specifier
      );
      let new_text = format!(
        "{}{}{}",
        &text[..insert_position],
        insert_text,
        &text[insert_position..],
      );
      format_json(&new_text, fmt_options)
        .ok()
        .map(|formatted_text| formatted_text.unwrap_or(new_text))
    }
    // shouldn't happen, so ignore
    Some(_) => None,
  }
}

fn is_dir_empty(dir_path: &Path) -> Result<bool, AnyError> {
  match std::fs::read_dir(dir_path) {
    Ok(mut dir) => Ok(dir.next().is_none()),
    Err(err) if err.kind() == std::io::ErrorKind::NotFound => Ok(true),
    Err(err) => {
      bail!("Error reading directory {}: {}", dir_path.display(), err)
    }
  }
}

async fn create_graph(
  ps: &ProcState,
  flags: &VendorFlags,
) -> Result<deno_graph::ModuleGraph, AnyError> {
  let entry_points = flags
    .specifiers
    .iter()
    .map(|p| {
      let url = resolve_url_or_path(p)?;
      Ok((url, deno_graph::ModuleKind::Esm))
    })
    .collect::<Result<Vec<_>, AnyError>>()?;

  ps.create_graph(entry_points).await
}

#[cfg(test)]
mod internal_test {
  use super::*;
  use pretty_assertions::assert_eq;

  #[test]
  fn update_config_text_no_existing_props_add_prop() {
    let text = update_config_text(
      "{\n}",
      "./vendor/import_map.json",
      &Default::default(),
    )
    .unwrap();
    assert_eq!(
      text,
      r#"{
  "importMap": "./vendor/import_map.json"
}
"#
    );
  }

  #[test]
  fn update_config_text_existing_props_add_prop() {
    let text = update_config_text(
      r#"{
  "tasks": {
    "task1": "other"
  }
}
"#,
      "./vendor/import_map.json",
      &Default::default(),
    )
    .unwrap();
    assert_eq!(
      text,
      r#"{
  "tasks": {
    "task1": "other"
  },
  "importMap": "./vendor/import_map.json"
}
"#
    );
  }

  #[test]
  fn update_config_text_update_prop() {
    let text = update_config_text(
      r#"{
  "importMap": "./local.json"
}
"#,
      "./vendor/import_map.json",
      &Default::default(),
    )
    .unwrap();
    assert_eq!(
      text,
      r#"{
  "importMap": "./vendor/import_map.json"
}
"#
    );
  }
}