// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.

use std::sync::Arc;

use deno_ast::MediaType;
use deno_ast::ModuleSpecifier;
use deno_core::error::AnyError;
use deno_core::serde_json;
use deno_graph::CapturingModuleParser;
use deno_graph::DefaultModuleAnalyzer;
use deno_graph::ModuleInfo;
use deno_graph::ModuleParser;
use deno_graph::ParsedSourceStore;
use deno_runtime::deno_webstorage::rusqlite::params;

use super::cache_db::CacheDB;
use super::cache_db::CacheDBConfiguration;
use super::cache_db::CacheFailure;
use super::FastInsecureHasher;

const SELECT_MODULE_INFO: &str = "
SELECT
  module_info
FROM
  moduleinfocache
WHERE
  specifier=?1
  AND media_type=?2
  AND source_hash=?3
LIMIT 1";

pub static MODULE_INFO_CACHE_DB: CacheDBConfiguration = CacheDBConfiguration {
  table_initializer: "CREATE TABLE IF NOT EXISTS moduleinfocache (
      specifier TEXT PRIMARY KEY,
      media_type TEXT NOT NULL,
      source_hash TEXT NOT NULL,
      module_info TEXT NOT NULL
    );",
  on_version_change: "DELETE FROM moduleinfocache;",
  preheat_queries: &[SELECT_MODULE_INFO],
  on_failure: CacheFailure::InMemory,
};

/// A cache of `deno_graph::ModuleInfo` objects. Using this leads to a considerable
/// performance improvement because when it exists we can skip parsing a module for
/// deno_graph.
pub struct ModuleInfoCache {
  conn: CacheDB,
}

impl ModuleInfoCache {
  #[cfg(test)]
  pub fn new_in_memory(version: &'static str) -> Self {
    Self::new(CacheDB::in_memory(&MODULE_INFO_CACHE_DB, version))
  }

  pub fn new(conn: CacheDB) -> Self {
    Self { conn }
  }

  /// Useful for testing: re-create this cache DB with a different current version.
  #[cfg(test)]
  pub(crate) fn recreate_with_version(self, version: &'static str) -> Self {
    Self {
      conn: self.conn.recreate_with_version(version),
    }
  }

  pub fn get_module_info(
    &self,
    specifier: &ModuleSpecifier,
    media_type: MediaType,
    expected_source_hash: &str,
  ) -> Result<Option<ModuleInfo>, AnyError> {
    let query = SELECT_MODULE_INFO;
    let res = self.conn.query_row(
      query,
      params![
        &specifier.as_str(),
        serialize_media_type(media_type),
        &expected_source_hash,
      ],
      |row| {
        let module_info: String = row.get(0)?;
        let module_info = serde_json::from_str(&module_info)?;
        Ok(module_info)
      },
    )?;
    Ok(res)
  }

  pub fn set_module_info(
    &self,
    specifier: &ModuleSpecifier,
    media_type: MediaType,
    source_hash: &str,
    module_info: &ModuleInfo,
  ) -> Result<(), AnyError> {
    let sql = "
      INSERT OR REPLACE INTO
        moduleinfocache (specifier, media_type, source_hash, module_info)
      VALUES
        (?1, ?2, ?3, ?4)";
    self.conn.execute(
      sql,
      params![
        specifier.as_str(),
        serialize_media_type(media_type),
        &source_hash,
        &serde_json::to_string(&module_info)?,
      ],
    )?;
    Ok(())
  }

  pub fn as_module_analyzer<'a>(
    &'a self,
    parser: Option<&'a dyn ModuleParser>,
    store: &'a dyn ParsedSourceStore,
  ) -> ModuleInfoCacheModuleAnalyzer<'a> {
    ModuleInfoCacheModuleAnalyzer {
      module_info_cache: self,
      parser: CapturingModuleParser::new(parser, store),
    }
  }
}

pub struct ModuleInfoCacheModuleAnalyzer<'a> {
  module_info_cache: &'a ModuleInfoCache,
  parser: CapturingModuleParser<'a>,
}

impl<'a> deno_graph::ModuleAnalyzer for ModuleInfoCacheModuleAnalyzer<'a> {
  fn analyze(
    &self,
    specifier: &ModuleSpecifier,
    source: Arc<str>,
    media_type: MediaType,
  ) -> Result<ModuleInfo, deno_ast::Diagnostic> {
    // attempt to load from the cache
    let source_hash = FastInsecureHasher::hash(source.as_bytes()).to_string();
    match self.module_info_cache.get_module_info(
      specifier,
      media_type,
      &source_hash,
    ) {
      Ok(Some(info)) => return Ok(info),
      Ok(None) => {}
      Err(err) => {
        log::debug!(
          "Error loading module cache info for {}. {:#}",
          specifier,
          err
        );
      }
    }

    // otherwise, get the module info from the parsed source cache
    let analyzer = DefaultModuleAnalyzer::new(&self.parser);
    let module_info = analyzer.analyze(specifier, source, media_type)?;

    // then attempt to cache it
    if let Err(err) = self.module_info_cache.set_module_info(
      specifier,
      media_type,
      &source_hash,
      &module_info,
    ) {
      log::debug!(
        "Error saving module cache info for {}. {:#}",
        specifier,
        err
      );
    }

    Ok(module_info)
  }
}

// todo(dsherret): change this to be stored as an integer next time
// the cache version is bumped
fn serialize_media_type(media_type: MediaType) -> &'static str {
  use MediaType::*;
  match media_type {
    JavaScript => "1",
    Jsx => "2",
    Mjs => "3",
    Cjs => "4",
    TypeScript => "5",
    Mts => "6",
    Cts => "7",
    Dts => "8",
    Dmts => "9",
    Dcts => "10",
    Tsx => "11",
    Json => "12",
    Wasm => "13",
    TsBuildInfo => "14",
    SourceMap => "15",
    Unknown => "16",
  }
}

#[cfg(test)]
mod test {
  use deno_graph::PositionRange;
  use deno_graph::SpecifierWithRange;

  use super::*;

  #[test]
  pub fn module_info_cache_general_use() {
    let cache = ModuleInfoCache::new_in_memory("1.0.0");
    let specifier1 =
      ModuleSpecifier::parse("https://localhost/mod.ts").unwrap();
    let specifier2 =
      ModuleSpecifier::parse("https://localhost/mod2.ts").unwrap();
    assert_eq!(
      cache
        .get_module_info(&specifier1, MediaType::JavaScript, "1")
        .unwrap(),
      None
    );

    let mut module_info = ModuleInfo::default();
    module_info.jsdoc_imports.push(SpecifierWithRange {
      range: PositionRange {
        start: deno_graph::Position {
          line: 0,
          character: 3,
        },
        end: deno_graph::Position {
          line: 1,
          character: 2,
        },
      },
      text: "test".to_string(),
    });
    cache
      .set_module_info(&specifier1, MediaType::JavaScript, "1", &module_info)
      .unwrap();
    assert_eq!(
      cache
        .get_module_info(&specifier1, MediaType::JavaScript, "1")
        .unwrap(),
      Some(module_info.clone())
    );
    assert_eq!(
      cache
        .get_module_info(&specifier2, MediaType::JavaScript, "1")
        .unwrap(),
      None,
    );
    // different media type
    assert_eq!(
      cache
        .get_module_info(&specifier1, MediaType::TypeScript, "1")
        .unwrap(),
      None,
    );
    // different source hash
    assert_eq!(
      cache
        .get_module_info(&specifier1, MediaType::JavaScript, "2")
        .unwrap(),
      None,
    );

    // try recreating with the same version
    let cache = cache.recreate_with_version("1.0.0");

    // should get it
    assert_eq!(
      cache
        .get_module_info(&specifier1, MediaType::JavaScript, "1")
        .unwrap(),
      Some(module_info)
    );

    // try recreating with a different version
    let cache = cache.recreate_with_version("1.0.1");

    // should no longer exist
    assert_eq!(
      cache
        .get_module_info(&specifier1, MediaType::JavaScript, "1")
        .unwrap(),
      None,
    );
  }
}