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

use crate::deno_dir;
use crate::file_fetcher::SourceFileFetcher;
use crate::flags;
use crate::http_cache;
use crate::import_map::ImportMap;
use crate::inspector::InspectorServer;
use crate::lockfile::Lockfile;
use crate::media_type::MediaType;
use crate::module_graph::ModuleGraphFile;
use crate::module_graph::ModuleGraphLoader;
use crate::module_graph2::GraphBuilder2;
use crate::module_graph2::TranspileOptions;
use crate::permissions::Permissions;
use crate::specifier_handler::FetchHandler;
use crate::tsc::CompiledModule;
use crate::tsc::TargetLib;
use crate::tsc::TsCompiler;
use deno_core::error::AnyError;
use deno_core::ModuleSpecifier;
use std::cell::RefCell;
use std::env;
use std::rc::Rc;
use std::sync::Arc;
use std::sync::Mutex;

pub fn exit_unstable(api_name: &str) {
  eprintln!(
    "Unstable API '{}'. The --unstable flag must be provided.",
    api_name
  );
  std::process::exit(70);
}

/// This structure represents state of single "deno" program.
///
/// It is shared by all created workers (thus V8 isolates).
pub struct GlobalState {
  /// Flags parsed from `argv` contents.
  pub flags: flags::Flags,
  /// Permissions parsed from `flags`.
  pub permissions: Permissions,
  pub dir: deno_dir::DenoDir,
  pub file_fetcher: SourceFileFetcher,
  pub ts_compiler: TsCompiler,
  pub lockfile: Option<Mutex<Lockfile>>,
  pub maybe_import_map: Option<ImportMap>,
  pub maybe_inspector_server: Option<Arc<InspectorServer>>,
}

impl GlobalState {
  pub fn new(flags: flags::Flags) -> Result<Arc<Self>, AnyError> {
    let custom_root = env::var("DENO_DIR").map(String::into).ok();
    let dir = deno_dir::DenoDir::new(custom_root)?;
    let deps_cache_location = dir.root.join("deps");
    let http_cache = http_cache::HttpCache::new(&deps_cache_location);
    let ca_file = flags.ca_file.clone().or_else(|| env::var("DENO_CERT").ok());

    let file_fetcher = SourceFileFetcher::new(
      http_cache,
      !flags.reload,
      flags.cache_blocklist.clone(),
      flags.no_remote,
      flags.cached_only,
      ca_file.as_deref(),
    )?;

    let ts_compiler = TsCompiler::new(
      file_fetcher.clone(),
      flags.clone(),
      dir.gen_cache.clone(),
    )?;

    let lockfile = if let Some(filename) = &flags.lock {
      let lockfile = Lockfile::new(filename.clone(), flags.lock_write)?;
      Some(Mutex::new(lockfile))
    } else {
      None
    };

    let maybe_import_map: Option<ImportMap> =
      match flags.import_map_path.as_ref() {
        None => None,
        Some(file_path) => {
          if !flags.unstable {
            exit_unstable("--importmap")
          }
          Some(ImportMap::load(file_path)?)
        }
      };

    let maybe_inspect_host = flags.inspect.or(flags.inspect_brk);
    let maybe_inspector_server = match maybe_inspect_host {
      Some(host) => Some(Arc::new(InspectorServer::new(host))),
      None => None,
    };

    let global_state = GlobalState {
      dir,
      permissions: Permissions::from_flags(&flags),
      flags,
      file_fetcher,
      ts_compiler,
      lockfile,
      maybe_import_map,
      maybe_inspector_server,
    };
    Ok(Arc::new(global_state))
  }

  /// This function is called when new module load is
  /// initialized by the JsRuntime. Its resposibility is to collect
  /// all dependencies and if it is required then also perform TS typecheck
  /// and traspilation.
  pub async fn prepare_module_load(
    self: &Arc<Self>,
    module_specifier: ModuleSpecifier,
    maybe_referrer: Option<ModuleSpecifier>,
    target_lib: TargetLib,
    permissions: Permissions,
    is_dyn_import: bool,
    maybe_import_map: Option<ImportMap>,
  ) -> Result<(), AnyError> {
    let module_specifier = module_specifier.clone();

    if self.flags.no_check {
      debug!("Transpiling root: {}", module_specifier);
      // TODO(kitsonk) note that self.permissions != permissions, which is
      // something that should be handled better in the future.
      let handler =
        Rc::new(RefCell::new(FetchHandler::new(self, permissions.clone())?));
      let mut builder = GraphBuilder2::new(handler, maybe_import_map);
      builder.insert(&module_specifier).await?;
      let mut graph = builder.get_graph(&self.lockfile)?;

      let (stats, maybe_ignored_options) =
        graph.transpile(TranspileOptions {
          debug: self.flags.log_level == Some(log::Level::Debug),
          maybe_config_path: self.flags.config_path.clone(),
        })?;

      if let Some(ignored_options) = maybe_ignored_options {
        eprintln!("{}", ignored_options);
      }

      debug!("{}", stats);
    } else {
      let mut module_graph_loader = ModuleGraphLoader::new(
        self.file_fetcher.clone(),
        maybe_import_map,
        permissions.clone(),
        is_dyn_import,
        false,
      );
      module_graph_loader
        .add_to_graph(&module_specifier, maybe_referrer)
        .await?;
      let module_graph = module_graph_loader.get_graph();

      let out = self
        .file_fetcher
        .fetch_cached_source_file(&module_specifier, permissions.clone())
        .expect("Source file not found");

      let module_graph_files = module_graph.values().collect::<Vec<_>>();
      // Check integrity of every file in module graph
      if let Some(ref lockfile) = self.lockfile {
        let mut g = lockfile.lock().unwrap();

        for graph_file in &module_graph_files {
          let check_passed =
            g.check_or_insert(&graph_file.url, &graph_file.source_code);

          if !check_passed {
            eprintln!(
              "Subresource integrity check failed --lock={}\n{}",
              g.filename, graph_file.url
            );
            std::process::exit(10);
          }
        }
      }

      // Check if we need to compile files.
      let should_compile = needs_compilation(
        self.ts_compiler.compile_js,
        out.media_type,
        &module_graph_files,
      );
      let allow_js = should_allow_js(&module_graph_files);

      if should_compile {
        self
          .ts_compiler
          .compile(self, &out, target_lib, &module_graph, allow_js)
          .await?;
      }
    }

    if let Some(ref lockfile) = self.lockfile {
      let g = lockfile.lock().unwrap();
      g.write()?;
    }

    Ok(())
  }

  // TODO(bartlomieju): this method doesn't need to be async anymore
  /// This method is used after `prepare_module_load` finishes and JsRuntime
  /// starts loading source and executing source code. This method shouldn't
  /// perform any IO (besides $DENO_DIR) and only operate on sources collected
  /// during `prepare_module_load`.
  pub async fn fetch_compiled_module(
    &self,
    module_specifier: ModuleSpecifier,
    _maybe_referrer: Option<ModuleSpecifier>,
  ) -> Result<CompiledModule, AnyError> {
    let out = self
      .file_fetcher
      .fetch_cached_source_file(&module_specifier, Permissions::allow_all())
      .expect("Cached source file doesn't exist");

    // Check if we need to compile files
    let was_compiled = match out.media_type {
      MediaType::TypeScript | MediaType::TSX | MediaType::JSX => true,
      MediaType::JavaScript => self.ts_compiler.compile_js,
      _ => false,
    };

    let compiled_module = if was_compiled {
      match self.ts_compiler.get_compiled_module(&out.url) {
        Ok(module) => module,
        Err(e) => {
          let msg = format!(
            "Failed to get compiled source code of \"{}\".\nReason: {}\n\
            If the source file provides only type exports, prefer to use \"import type\" or \"export type\" syntax instead.",
            out.url, e.to_string()
          );
          info!("{} {}", crate::colors::yellow("Warning"), msg);

          CompiledModule {
            code: "".to_string(),
            name: out.url.to_string(),
          }
        }
      }
    } else {
      CompiledModule {
        code: out.source_code,
        name: out.url.to_string(),
      }
    };

    Ok(compiled_module)
  }

  /// Quits the process if the --unstable flag was not provided.
  ///
  /// This is intentionally a non-recoverable check so that people cannot probe
  /// for unstable APIs from stable programs.
  pub fn check_unstable(&self, api_name: &str) {
    if !self.flags.unstable {
      exit_unstable(api_name);
    }
  }

  #[cfg(test)]
  pub fn mock(
    argv: Vec<String>,
    maybe_flags: Option<flags::Flags>,
  ) -> Arc<GlobalState> {
    GlobalState::new(flags::Flags {
      argv,
      ..maybe_flags.unwrap_or_default()
    })
    .unwrap()
  }
}

/// Determine if TS compiler should be run with `allowJs` setting on. This
/// is the case when there's either:
///  - a JavaScript file with non-JavaScript import
///  - JSX import
fn should_allow_js(module_graph_files: &[&ModuleGraphFile]) -> bool {
  module_graph_files.iter().any(|module_file| {
    if module_file.media_type == MediaType::JSX {
      true
    } else if module_file.media_type == MediaType::JavaScript {
      module_file.imports.iter().any(|import_desc| {
        let import_file = module_graph_files
          .iter()
          .find(|f| {
            f.specifier == import_desc.resolved_specifier.to_string().as_str()
          })
          .expect("Failed to find imported file");
        let media_type = import_file.media_type;
        media_type == MediaType::TypeScript
          || media_type == MediaType::TSX
          || media_type == MediaType::JSX
      })
    } else {
      false
    }
  })
}

// Compilation happens if either:
// - `checkJs` is set to true in TS config
// - entry point is a TS file
// - any dependency in module graph is a TS file
fn needs_compilation(
  compile_js: bool,
  media_type: MediaType,
  module_graph_files: &[&ModuleGraphFile],
) -> bool {
  let mut needs_compilation = match media_type {
    MediaType::TypeScript | MediaType::TSX | MediaType::JSX => true,
    MediaType::JavaScript => compile_js,
    _ => false,
  };

  needs_compilation |= module_graph_files.iter().any(|module_file| {
    let media_type = module_file.media_type;

    media_type == (MediaType::TypeScript)
      || media_type == (MediaType::TSX)
      || media_type == (MediaType::JSX)
  });

  needs_compilation
}

#[test]
fn thread_safe() {
  fn f<S: Send + Sync>(_: S) {}
  f(GlobalState::mock(vec![], None));
}

#[test]
fn test_should_allow_js() {
  use crate::ast::Location;
  use crate::module_graph::ImportDescriptor;

  assert!(should_allow_js(&[
    &ModuleGraphFile {
      specifier: "file:///some/file.ts".to_string(),
      url: "file:///some/file.ts".to_string(),
      redirect: None,
      filename: "some/file.ts".to_string(),
      imports: vec![],
      version_hash: "1".to_string(),
      referenced_files: vec![],
      lib_directives: vec![],
      types_directives: vec![],
      type_headers: vec![],
      media_type: MediaType::TypeScript,
      source_code: "function foo() {}".to_string(),
    },
    &ModuleGraphFile {
      specifier: "file:///some/file1.js".to_string(),
      url: "file:///some/file1.js".to_string(),
      redirect: None,
      filename: "some/file1.js".to_string(),
      version_hash: "1".to_string(),
      imports: vec![ImportDescriptor {
        specifier: "./file.ts".to_string(),
        resolved_specifier: ModuleSpecifier::resolve_url(
          "file:///some/file.ts",
        )
        .unwrap(),
        type_directive: None,
        resolved_type_directive: None,
        location: Location {
          filename: "file:///some/file1.js".to_string(),
          line: 0,
          col: 0,
        },
      }],
      referenced_files: vec![],
      lib_directives: vec![],
      types_directives: vec![],
      type_headers: vec![],
      media_type: MediaType::JavaScript,
      source_code: "function foo() {}".to_string(),
    },
  ],));

  assert!(should_allow_js(&[
    &ModuleGraphFile {
      specifier: "file:///some/file.jsx".to_string(),
      url: "file:///some/file.jsx".to_string(),
      redirect: None,
      filename: "some/file.jsx".to_string(),
      imports: vec![],
      version_hash: "1".to_string(),
      referenced_files: vec![],
      lib_directives: vec![],
      types_directives: vec![],
      type_headers: vec![],
      media_type: MediaType::JSX,
      source_code: "function foo() {}".to_string(),
    },
    &ModuleGraphFile {
      specifier: "file:///some/file.ts".to_string(),
      url: "file:///some/file.ts".to_string(),
      redirect: None,
      filename: "some/file.ts".to_string(),
      version_hash: "1".to_string(),
      imports: vec![ImportDescriptor {
        specifier: "./file.jsx".to_string(),
        resolved_specifier: ModuleSpecifier::resolve_url(
          "file:///some/file.jsx",
        )
        .unwrap(),
        type_directive: None,
        resolved_type_directive: None,
        location: Location {
          filename: "file:///some/file1.ts".to_string(),
          line: 0,
          col: 0,
        },
      }],
      referenced_files: vec![],
      lib_directives: vec![],
      types_directives: vec![],
      type_headers: vec![],
      media_type: MediaType::TypeScript,
      source_code: "function foo() {}".to_string(),
    },
  ]));

  assert!(!should_allow_js(&[
    &ModuleGraphFile {
      specifier: "file:///some/file.js".to_string(),
      url: "file:///some/file.js".to_string(),
      redirect: None,
      filename: "some/file.js".to_string(),
      imports: vec![],
      referenced_files: vec![],
      lib_directives: vec![],
      types_directives: vec![],
      version_hash: "1".to_string(),
      type_headers: vec![],
      media_type: MediaType::JavaScript,
      source_code: "function foo() {}".to_string(),
    },
    &ModuleGraphFile {
      specifier: "file:///some/file1.js".to_string(),
      url: "file:///some/file1.js".to_string(),
      redirect: None,
      filename: "some/file1.js".to_string(),
      imports: vec![ImportDescriptor {
        specifier: "./file.js".to_string(),
        resolved_specifier: ModuleSpecifier::resolve_url(
          "file:///some/file.js",
        )
        .unwrap(),
        type_directive: None,
        resolved_type_directive: None,
        location: Location {
          filename: "file:///some/file.js".to_string(),
          line: 0,
          col: 0,
        },
      }],
      referenced_files: vec![],
      lib_directives: vec![],
      types_directives: vec![],
      version_hash: "1".to_string(),
      type_headers: vec![],
      media_type: MediaType::JavaScript,
      source_code: "function foo() {}".to_string(),
    },
  ],));
}

#[test]
fn test_needs_compilation() {
  assert!(!needs_compilation(
    false,
    MediaType::JavaScript,
    &[&ModuleGraphFile {
      specifier: "some/file.js".to_string(),
      url: "file:///some/file.js".to_string(),
      redirect: None,
      filename: "some/file.js".to_string(),
      imports: vec![],
      referenced_files: vec![],
      lib_directives: vec![],
      types_directives: vec![],
      type_headers: vec![],
      version_hash: "1".to_string(),
      media_type: MediaType::JavaScript,
      source_code: "function foo() {}".to_string(),
    }],
  ));

  assert!(!needs_compilation(false, MediaType::JavaScript, &[]));
  assert!(needs_compilation(true, MediaType::JavaScript, &[]));
  assert!(needs_compilation(false, MediaType::TypeScript, &[]));
  assert!(needs_compilation(false, MediaType::JSX, &[]));
  assert!(needs_compilation(false, MediaType::TSX, &[]));
  assert!(needs_compilation(
    false,
    MediaType::JavaScript,
    &[
      &ModuleGraphFile {
        specifier: "file:///some/file.ts".to_string(),
        url: "file:///some/file.ts".to_string(),
        redirect: None,
        filename: "some/file.ts".to_string(),
        imports: vec![],
        referenced_files: vec![],
        lib_directives: vec![],
        types_directives: vec![],
        type_headers: vec![],
        media_type: MediaType::TypeScript,
        version_hash: "1".to_string(),
        source_code: "function foo() {}".to_string(),
      },
      &ModuleGraphFile {
        specifier: "file:///some/file1.js".to_string(),
        url: "file:///some/file1.js".to_string(),
        redirect: None,
        filename: "some/file1.js".to_string(),
        imports: vec![],
        referenced_files: vec![],
        lib_directives: vec![],
        types_directives: vec![],
        type_headers: vec![],
        version_hash: "1".to_string(),
        media_type: MediaType::JavaScript,
        source_code: "function foo() {}".to_string(),
      },
    ],
  ));
}