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

//! The collection of APIs to be able to take `deno_graph` module graphs and
//! populate a cache, emit files, and transform a graph into the structures for
//! loading into an isolate.

use crate::args::config_file::IgnoredCompilerOptions;
use crate::args::ConfigFile;
use crate::args::EmitConfigOptions;
use crate::args::TsConfig;
use crate::args::TypeCheckMode;
use crate::cache::EmitCache;
use crate::cache::FastInsecureHasher;
use crate::cache::ParsedSourceCache;
use crate::cache::TypeCheckCache;
use crate::colors;
use crate::diagnostics::Diagnostics;
use crate::graph_util::GraphData;
use crate::graph_util::ModuleEntry;
use crate::tsc;
use crate::version;

use deno_ast::swc::bundler::Hook;
use deno_ast::swc::bundler::ModuleRecord;
use deno_ast::swc::common::Span;
use deno_core::error::AnyError;
use deno_core::parking_lot::RwLock;
use deno_core::serde::Deserialize;
use deno_core::serde::Deserializer;
use deno_core::serde::Serialize;
use deno_core::serde::Serializer;
use deno_core::serde_json;
use deno_core::serde_json::json;
use deno_core::ModuleSpecifier;
use deno_graph::MediaType;
use deno_graph::ModuleGraphError;
use deno_graph::ModuleKind;
use deno_graph::ResolutionError;
use once_cell::sync::Lazy;
use regex::Regex;
use std::fmt;
use std::sync::Arc;

/// A structure representing stats from an emit operation for a graph.
#[derive(Clone, Debug, Default, Eq, PartialEq)]
pub struct Stats(pub Vec<(String, u32)>);

impl<'de> Deserialize<'de> for Stats {
  fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
  where
    D: Deserializer<'de>,
  {
    let items: Vec<(String, u32)> = Deserialize::deserialize(deserializer)?;
    Ok(Stats(items))
  }
}

impl Serialize for Stats {
  fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
  where
    S: Serializer,
  {
    Serialize::serialize(&self.0, serializer)
  }
}

impl fmt::Display for Stats {
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
    writeln!(f, "Compilation statistics:")?;
    for (key, value) in self.0.clone() {
      writeln!(f, "  {}: {}", key, value)?;
    }

    Ok(())
  }
}

/// Represents the "default" type library that should be used when type
/// checking the code in the module graph.  Note that a user provided config
/// of `"lib"` would override this value.
#[derive(Debug, Clone, Copy, Eq, Hash, PartialEq)]
pub enum TsTypeLib {
  DenoWindow,
  DenoWorker,
  UnstableDenoWindow,
  UnstableDenoWorker,
}

impl Default for TsTypeLib {
  fn default() -> Self {
    Self::DenoWindow
  }
}

impl Serialize for TsTypeLib {
  fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
  where
    S: Serializer,
  {
    let value = match self {
      Self::DenoWindow => vec!["deno.window".to_string()],
      Self::DenoWorker => vec!["deno.worker".to_string()],
      Self::UnstableDenoWindow => {
        vec!["deno.window".to_string(), "deno.unstable".to_string()]
      }
      Self::UnstableDenoWorker => {
        vec!["deno.worker".to_string(), "deno.unstable".to_string()]
      }
    };
    Serialize::serialize(&value, serializer)
  }
}

/// An enum that represents the base tsc configuration to return.
pub enum TsConfigType {
  /// Return a configuration for bundling, using swc to emit the bundle. This is
  /// independent of type checking.
  Bundle,
  /// Return a configuration to use tsc to type check. This
  /// is independent of either bundling or emitting via swc.
  Check { lib: TsTypeLib },
  /// Return a configuration to use swc to emit single module files.
  Emit,
}

pub struct TsConfigWithIgnoredOptions {
  pub ts_config: TsConfig,
  pub maybe_ignored_options: Option<IgnoredCompilerOptions>,
}

/// For a given configuration type and optionally a configuration file,
/// return a `TsConfig` struct and optionally any user configuration
/// options that were ignored.
pub fn get_ts_config_for_emit(
  config_type: TsConfigType,
  maybe_config_file: Option<&ConfigFile>,
) -> Result<TsConfigWithIgnoredOptions, AnyError> {
  let mut ts_config = match config_type {
    TsConfigType::Bundle => TsConfig::new(json!({
      "checkJs": false,
      "emitDecoratorMetadata": false,
      "importsNotUsedAsValues": "remove",
      "inlineSourceMap": false,
      "inlineSources": false,
      "sourceMap": false,
      "jsx": "react",
      "jsxFactory": "React.createElement",
      "jsxFragmentFactory": "React.Fragment",
    })),
    TsConfigType::Check { lib } => TsConfig::new(json!({
      "allowJs": true,
      "allowSyntheticDefaultImports": true,
      "checkJs": false,
      "emitDecoratorMetadata": false,
      "experimentalDecorators": true,
      "incremental": true,
      "jsx": "react",
      "importsNotUsedAsValues": "remove",
      "inlineSourceMap": true,
      "inlineSources": true,
      "isolatedModules": true,
      "lib": lib,
      "module": "esnext",
      "moduleDetection": "force",
      "noEmit": true,
      "resolveJsonModule": true,
      "sourceMap": false,
      "strict": true,
      "target": "esnext",
      "tsBuildInfoFile": "deno:///.tsbuildinfo",
      "useDefineForClassFields": true,
      // TODO(@kitsonk) remove for Deno 2.0
      "useUnknownInCatchVariables": false,
    })),
    TsConfigType::Emit => TsConfig::new(json!({
      "checkJs": false,
      "emitDecoratorMetadata": false,
      "importsNotUsedAsValues": "remove",
      "inlineSourceMap": true,
      "inlineSources": true,
      "sourceMap": false,
      "jsx": "react",
      "jsxFactory": "React.createElement",
      "jsxFragmentFactory": "React.Fragment",
      "resolveJsonModule": true,
    })),
  };
  let maybe_ignored_options =
    ts_config.merge_tsconfig_from_config_file(maybe_config_file)?;
  Ok(TsConfigWithIgnoredOptions {
    ts_config,
    maybe_ignored_options,
  })
}

/// Transform the graph into root specifiers that we can feed `tsc`. We have to
/// provide the media type for root modules because `tsc` does not "resolve" the
/// media type like other modules, as well as a root specifier needs any
/// redirects resolved. We need to include all the emittable files in
/// the roots, so they get type checked and optionally emitted,
/// otherwise they would be ignored if only imported into JavaScript.
fn get_tsc_roots(
  graph_data: &GraphData,
  check_js: bool,
) -> Vec<(ModuleSpecifier, MediaType)> {
  graph_data
    .entries()
    .into_iter()
    .filter_map(|(specifier, module_entry)| match module_entry {
      ModuleEntry::Module {
        media_type, code, ..
      } => match media_type {
        MediaType::TypeScript
        | MediaType::Tsx
        | MediaType::Mts
        | MediaType::Cts
        | MediaType::Jsx => Some((specifier.clone(), *media_type)),
        MediaType::JavaScript | MediaType::Mjs | MediaType::Cjs
          if check_js || has_ts_check(*media_type, code) =>
        {
          Some((specifier.clone(), *media_type))
        }
        _ => None,
      },
      _ => None,
    })
    .collect()
}

/// A hashing function that takes the source code, version and optionally a
/// user provided config and generates a string hash which can be stored to
/// determine if the cached emit is valid or not.
pub fn get_source_hash(source_text: &str, emit_options_hash: u64) -> u64 {
  FastInsecureHasher::new()
    .write_str(source_text)
    .write_u64(emit_options_hash)
    .finish()
}

pub fn emit_parsed_source(
  emit_cache: &EmitCache,
  parsed_source_cache: &ParsedSourceCache,
  specifier: &ModuleSpecifier,
  media_type: MediaType,
  source: &Arc<str>,
  emit_options: &deno_ast::EmitOptions,
  emit_config_hash: u64,
) -> Result<String, AnyError> {
  let source_hash = get_source_hash(source, emit_config_hash);

  if let Some(emit_code) =
    emit_cache.get_emit_code(specifier, Some(source_hash))
  {
    Ok(emit_code)
  } else {
    // this will use a cached version if it exists
    let parsed_source = parsed_source_cache.get_or_parse_module(
      specifier,
      source.clone(),
      media_type,
    )?;
    let transpiled_source = parsed_source.transpile(emit_options)?;
    debug_assert!(transpiled_source.source_map.is_none());
    emit_cache.set_emit_code(specifier, source_hash, &transpiled_source.text);
    Ok(transpiled_source.text)
  }
}

/// Options for performing a check of a module graph. Note that the decision to
/// emit or not is determined by the `ts_config` settings.
pub struct CheckOptions {
  /// The check flag from the option which can effect the filtering of
  /// diagnostics in the emit result.
  pub type_check_mode: TypeCheckMode,
  /// Set the debug flag on the TypeScript type checker.
  pub debug: bool,
  /// The module specifier to the configuration file, passed to tsc so that
  /// configuration related diagnostics are properly formed.
  pub maybe_config_specifier: Option<ModuleSpecifier>,
  /// The derived tsconfig that should be used when checking.
  pub ts_config: TsConfig,
  /// If true, `Check <specifier>` will be written to stdout for each root.
  pub log_checks: bool,
  /// If true, valid `.tsbuildinfo` files will be ignored and type checking
  /// will always occur.
  pub reload: bool,
}

/// The result of a check of a module graph.
#[derive(Debug, Default)]
pub struct CheckResult {
  pub diagnostics: Diagnostics,
  pub stats: Stats,
}

/// Given a set of roots and graph data, type check the module graph.
///
/// It is expected that it is determined if a check and/or emit is validated
/// before the function is called.
pub fn check(
  roots: &[(ModuleSpecifier, ModuleKind)],
  graph_data: Arc<RwLock<GraphData>>,
  cache: &TypeCheckCache,
  options: CheckOptions,
) -> Result<CheckResult, AnyError> {
  let check_js = options.ts_config.get_check_js();
  let segment_graph_data = {
    let graph_data = graph_data.read();
    graph_data.graph_segment(roots).unwrap()
  };
  let check_hash = match get_check_hash(&segment_graph_data, &options) {
    CheckHashResult::NoFiles => return Ok(Default::default()),
    CheckHashResult::Hash(hash) => hash,
  };

  // do not type check if we know this is type checked
  if !options.reload && cache.has_check_hash(check_hash) {
    return Ok(Default::default());
  }

  let root_names = get_tsc_roots(&segment_graph_data, check_js);
  if options.log_checks {
    for (root, _) in roots {
      let root_str = root.to_string();
      // `$deno` specifiers are internal, don't print them.
      if !root_str.contains("$deno") {
        log::info!("{} {}", colors::green("Check"), root);
      }
    }
  }
  // while there might be multiple roots, we can't "merge" the build info, so we
  // try to retrieve the build info for first root, which is the most common use
  // case.
  let maybe_tsbuildinfo = if options.reload {
    None
  } else {
    cache.get_tsbuildinfo(&roots[0].0)
  };
  // to make tsc build info work, we need to consistently hash modules, so that
  // tsc can better determine if an emit is still valid or not, so we provide
  // that data here.
  let hash_data = vec![
    options.ts_config.as_bytes(),
    version::deno().as_bytes().to_owned(),
  ];

  let response = tsc::exec(tsc::Request {
    config: options.ts_config,
    debug: options.debug,
    graph_data,
    hash_data,
    maybe_config_specifier: options.maybe_config_specifier,
    maybe_tsbuildinfo,
    root_names,
  })?;

  let diagnostics = if options.type_check_mode == TypeCheckMode::Local {
    response.diagnostics.filter(|d| {
      if let Some(file_name) = &d.file_name {
        !file_name.starts_with("http")
      } else {
        true
      }
    })
  } else {
    response.diagnostics
  };

  if let Some(tsbuildinfo) = response.maybe_tsbuildinfo {
    cache.set_tsbuildinfo(&roots[0].0, &tsbuildinfo);
  }

  if diagnostics.is_empty() {
    cache.add_check_hash(check_hash);
  }

  Ok(CheckResult {
    diagnostics,
    stats: response.stats,
  })
}

enum CheckHashResult {
  Hash(u64),
  NoFiles,
}

/// Gets a hash of the inputs for type checking. This can then
/// be used to tell
fn get_check_hash(
  graph_data: &GraphData,
  options: &CheckOptions,
) -> CheckHashResult {
  let mut hasher = FastInsecureHasher::new();
  hasher.write_u8(match options.type_check_mode {
    TypeCheckMode::All => 0,
    TypeCheckMode::Local => 1,
    TypeCheckMode::None => 2,
  });
  hasher.write(&options.ts_config.as_bytes());

  let check_js = options.ts_config.get_check_js();
  let mut sorted_entries = graph_data.entries().collect::<Vec<_>>();
  sorted_entries.sort_by_key(|(s, _)| s.as_str()); // make it deterministic
  let mut has_file = false;
  let mut has_file_to_type_check = false;
  for (specifier, module_entry) in sorted_entries {
    if let ModuleEntry::Module {
      code, media_type, ..
    } = module_entry
    {
      let ts_check = has_ts_check(*media_type, code);
      if ts_check {
        has_file_to_type_check = true;
      }

      match media_type {
        MediaType::TypeScript
        | MediaType::Dts
        | MediaType::Dmts
        | MediaType::Dcts
        | MediaType::Mts
        | MediaType::Cts
        | MediaType::Tsx => {
          has_file = true;
          has_file_to_type_check = true;
        }
        MediaType::JavaScript
        | MediaType::Mjs
        | MediaType::Cjs
        | MediaType::Jsx => {
          has_file = true;
          if !check_js && !ts_check {
            continue;
          }
        }
        MediaType::Json
        | MediaType::TsBuildInfo
        | MediaType::SourceMap
        | MediaType::Wasm
        | MediaType::Unknown => continue,
      }
      hasher.write_str(specifier.as_str());
      hasher.write_str(code);
    }
  }

  if !has_file || !check_js && !has_file_to_type_check {
    // no files to type check
    CheckHashResult::NoFiles
  } else {
    CheckHashResult::Hash(hasher.finish())
  }
}

/// An adapter struct to make a deno_graph::ModuleGraphError display as expected
/// in the Deno CLI.
#[derive(Debug)]
pub struct GraphError(pub ModuleGraphError);

impl std::error::Error for GraphError {}

impl From<ModuleGraphError> for GraphError {
  fn from(err: ModuleGraphError) -> Self {
    Self(err)
  }
}

impl fmt::Display for GraphError {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
    match &self.0 {
      ModuleGraphError::ResolutionError(err) => {
        if matches!(
          err,
          ResolutionError::InvalidDowngrade { .. }
            | ResolutionError::InvalidLocalImport { .. }
        ) {
          write!(f, "{}", err.to_string_with_range())
        } else {
          self.0.fmt(f)
        }
      }
      _ => self.0.fmt(f),
    }
  }
}

/// This contains the logic for Deno to rewrite the `import.meta` when bundling.
pub struct BundleHook;

impl Hook for BundleHook {
  fn get_import_meta_props(
    &self,
    span: Span,
    module_record: &ModuleRecord,
  ) -> Result<Vec<deno_ast::swc::ast::KeyValueProp>, AnyError> {
    use deno_ast::swc::ast;

    Ok(vec![
      ast::KeyValueProp {
        key: ast::PropName::Ident(ast::Ident::new("url".into(), span)),
        value: Box::new(ast::Expr::Lit(ast::Lit::Str(ast::Str {
          span,
          value: module_record.file_name.to_string().into(),
          raw: None,
        }))),
      },
      ast::KeyValueProp {
        key: ast::PropName::Ident(ast::Ident::new("main".into(), span)),
        value: Box::new(if module_record.is_entry {
          ast::Expr::Member(ast::MemberExpr {
            span,
            obj: Box::new(ast::Expr::MetaProp(ast::MetaPropExpr {
              span,
              kind: ast::MetaPropKind::ImportMeta,
            })),
            prop: ast::MemberProp::Ident(ast::Ident::new("main".into(), span)),
          })
        } else {
          ast::Expr::Lit(ast::Lit::Bool(ast::Bool { span, value: false }))
        }),
      },
    ])
  }
}

impl From<TsConfig> for deno_ast::EmitOptions {
  fn from(config: TsConfig) -> Self {
    let options: EmitConfigOptions = serde_json::from_value(config.0).unwrap();
    let imports_not_used_as_values =
      match options.imports_not_used_as_values.as_str() {
        "preserve" => deno_ast::ImportsNotUsedAsValues::Preserve,
        "error" => deno_ast::ImportsNotUsedAsValues::Error,
        _ => deno_ast::ImportsNotUsedAsValues::Remove,
      };
    let (transform_jsx, jsx_automatic, jsx_development) =
      match options.jsx.as_str() {
        "react" => (true, false, false),
        "react-jsx" => (true, true, false),
        "react-jsxdev" => (true, true, true),
        _ => (false, false, false),
      };
    deno_ast::EmitOptions {
      emit_metadata: options.emit_decorator_metadata,
      imports_not_used_as_values,
      inline_source_map: options.inline_source_map,
      inline_sources: options.inline_sources,
      source_map: options.source_map,
      jsx_automatic,
      jsx_development,
      jsx_factory: options.jsx_factory,
      jsx_fragment_factory: options.jsx_fragment_factory,
      jsx_import_source: options.jsx_import_source,
      transform_jsx,
      var_decl_imports: false,
    }
  }
}

/// Matches the `@ts-check` pragma.
static TS_CHECK_RE: Lazy<Regex> =
  Lazy::new(|| Regex::new(r#"(?i)^\s*@ts-check(?:\s+|$)"#).unwrap());

fn has_ts_check(media_type: MediaType, file_text: &str) -> bool {
  match &media_type {
    MediaType::JavaScript
    | MediaType::Mjs
    | MediaType::Cjs
    | MediaType::Jsx => get_leading_comments(file_text)
      .iter()
      .any(|text| TS_CHECK_RE.is_match(text)),
    _ => false,
  }
}

fn get_leading_comments(file_text: &str) -> Vec<String> {
  let mut chars = file_text.chars().peekable();

  // skip over the shebang
  if file_text.starts_with("#!") {
    // skip until the end of the line
    for c in chars.by_ref() {
      if c == '\n' {
        break;
      }
    }
  }

  let mut results = Vec::new();
  // now handle the comments
  while chars.peek().is_some() {
    // skip over any whitespace
    while chars
      .peek()
      .map(|c| char::is_whitespace(*c))
      .unwrap_or(false)
    {
      chars.next();
    }

    if chars.next() != Some('/') {
      break;
    }
    match chars.next() {
      Some('/') => {
        let mut text = String::new();
        for c in chars.by_ref() {
          if c == '\n' {
            break;
          } else {
            text.push(c);
          }
        }
        results.push(text);
      }
      Some('*') => {
        let mut text = String::new();
        while let Some(c) = chars.next() {
          if c == '*' && chars.peek() == Some(&'/') {
            chars.next();
            break;
          } else {
            text.push(c);
          }
        }
        results.push(text);
      }
      _ => break,
    }
  }
  results
}

#[cfg(test)]
mod test {
  use deno_ast::MediaType;

  use super::get_leading_comments;
  use super::has_ts_check;

  #[test]
  fn get_leading_comments_test() {
    assert_eq!(
      get_leading_comments(
        "#!/usr/bin/env deno\r\n// test\n/* 1 *//*2*///3\n//\n /**/  /*4 */"
      ),
      vec![
        " test".to_string(),
        " 1 ".to_string(),
        "2".to_string(),
        "3".to_string(),
        "".to_string(),
        "".to_string(),
        "4 ".to_string(),
      ]
    );
    assert_eq!(
      get_leading_comments("//1 /* */ \na;"),
      vec!["1 /* */ ".to_string(),]
    );
    assert_eq!(get_leading_comments("//"), vec!["".to_string()]);
  }

  #[test]
  fn has_ts_check_test() {
    assert!(has_ts_check(
      MediaType::JavaScript,
      "// @ts-check\nconsole.log(5);"
    ));
    assert!(has_ts_check(
      MediaType::JavaScript,
      "// deno-lint-ignore\n// @ts-check\n"
    ));
    assert!(!has_ts_check(
      MediaType::JavaScript,
      "test;\n// @ts-check\n"
    ));
    assert!(!has_ts_check(
      MediaType::JavaScript,
      "// ts-check\nconsole.log(5);"
    ));
  }
}