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

use super::cache_db::CacheDB;
use super::cache_db::CacheDBConfiguration;
use super::cache_db::CacheFailure;
use deno_ast::ModuleSpecifier;
use deno_core::error::AnyError;
use deno_runtime::deno_webstorage::rusqlite::params;

pub static TYPE_CHECK_CACHE_DB: CacheDBConfiguration = CacheDBConfiguration {
  table_initializer: concat!(
    "CREATE TABLE IF NOT EXISTS checkcache (
      check_hash TEXT PRIMARY KEY
    );",
    "CREATE TABLE IF NOT EXISTS tsbuildinfo (
      specifier TEXT PRIMARY KEY,
      text TEXT NOT NULL
    );",
  ),
  on_version_change: concat!(
    "DELETE FROM checkcache;",
    "DELETE FROM tsbuildinfo;"
  ),
  preheat_queries: &[],
  // If the cache fails, just ignore all caching attempts
  on_failure: CacheFailure::Blackhole,
};

/// The cache used to tell whether type checking should occur again.
///
/// This simply stores a hash of the inputs of each successful type check
/// and only clears them out when changing CLI versions.
pub struct TypeCheckCache(CacheDB);

impl TypeCheckCache {
  pub fn new(db: CacheDB) -> Self {
    Self(db)
  }

  pub fn has_check_hash(&self, hash: u64) -> bool {
    match self.hash_check_hash_result(hash) {
      Ok(val) => val,
      Err(err) => {
        if cfg!(debug_assertions) {
          panic!("Error retrieving hash: {err}");
        } else {
          log::debug!("Error retrieving hash: {}", err);
          // fail silently when not debugging
          false
        }
      }
    }
  }

  fn hash_check_hash_result(&self, hash: u64) -> Result<bool, AnyError> {
    self.0.exists(
      "SELECT * FROM checkcache WHERE check_hash=?1 LIMIT 1",
      params![hash.to_string()],
    )
  }

  pub fn add_check_hash(&self, check_hash: u64) {
    if let Err(err) = self.add_check_hash_result(check_hash) {
      if cfg!(debug_assertions) {
        panic!("Error saving check hash: {err}");
      } else {
        log::debug!("Error saving check hash: {}", err);
      }
    }
  }

  fn add_check_hash_result(&self, check_hash: u64) -> Result<(), AnyError> {
    let sql = "
    INSERT OR REPLACE INTO
      checkcache (check_hash)
    VALUES
      (?1)";
    self.0.execute(sql, params![&check_hash.to_string(),])?;
    Ok(())
  }

  pub fn get_tsbuildinfo(&self, specifier: &ModuleSpecifier) -> Option<String> {
    self
      .0
      .query_row(
        "SELECT text FROM tsbuildinfo WHERE specifier=?1 LIMIT 1",
        params![specifier.to_string()],
        |row| Ok(row.get::<_, String>(0)?),
      )
      .ok()?
  }

  pub fn set_tsbuildinfo(&self, specifier: &ModuleSpecifier, text: &str) {
    if let Err(err) = self.set_tsbuildinfo_result(specifier, text) {
      // should never error here, but if it ever does don't fail
      if cfg!(debug_assertions) {
        panic!("Error saving tsbuildinfo: {err}");
      } else {
        log::debug!("Error saving tsbuildinfo: {}", err);
      }
    }
  }

  fn set_tsbuildinfo_result(
    &self,
    specifier: &ModuleSpecifier,
    text: &str,
  ) -> Result<(), AnyError> {
    self.0.execute(
      "INSERT OR REPLACE INTO tsbuildinfo (specifier, text) VALUES (?1, ?2)",
      params![specifier.to_string(), text],
    )?;
    Ok(())
  }
}

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

  #[test]
  pub fn check_cache_general_use() {
    let conn = CacheDB::in_memory(&TYPE_CHECK_CACHE_DB, "1.0.0");
    let cache = TypeCheckCache::new(conn);

    assert!(!cache.has_check_hash(1));
    cache.add_check_hash(1);
    assert!(cache.has_check_hash(1));
    assert!(!cache.has_check_hash(2));

    let specifier1 = ModuleSpecifier::parse("file:///test.json").unwrap();
    assert_eq!(cache.get_tsbuildinfo(&specifier1), None);
    cache.set_tsbuildinfo(&specifier1, "test");
    assert_eq!(cache.get_tsbuildinfo(&specifier1), Some("test".to_string()));

    // try changing the cli version (should clear)
    let conn = cache.0.recreate_with_version("2.0.0");
    let cache = TypeCheckCache::new(conn);

    assert!(!cache.has_check_hash(1));
    cache.add_check_hash(1);
    assert!(cache.has_check_hash(1));
    assert_eq!(cache.get_tsbuildinfo(&specifier1), None);
    cache.set_tsbuildinfo(&specifier1, "test");
    assert_eq!(cache.get_tsbuildinfo(&specifier1), Some("test".to_string()));

    // recreating the cache should not remove the data because the CLI version is the same
    let conn = cache.0.recreate_with_version("2.0.0");
    let cache = TypeCheckCache::new(conn);

    assert!(cache.has_check_hash(1));
    assert!(!cache.has_check_hash(2));
    assert_eq!(cache.get_tsbuildinfo(&specifier1), Some("test".to_string()));

    // adding when already exists should not cause issue
    cache.add_check_hash(1);
    assert!(cache.has_check_hash(1));
    cache.set_tsbuildinfo(&specifier1, "other");
    assert_eq!(
      cache.get_tsbuildinfo(&specifier1),
      Some("other".to_string())
    );
  }
}