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

mod sqlite;
use deno_core::ByteString;
pub use sqlite::SqliteBackedCache;

use async_trait::async_trait;
use deno_core::error::AnyError;
use deno_core::include_js_files;
use deno_core::op;
use deno_core::serde::Deserialize;
use deno_core::serde::Serialize;
use deno_core::Extension;
use deno_core::OpState;
use deno_core::Resource;
use deno_core::ResourceId;

use std::cell::RefCell;
use std::path::PathBuf;
use std::rc::Rc;
use std::sync::Arc;

#[derive(Deserialize, Serialize, Debug, Clone)]
#[serde(rename_all = "camelCase")]
pub struct CachePutRequest {
  pub cache_id: i64,
  pub request_url: String,
  pub request_headers: Vec<(ByteString, ByteString)>,
  pub response_headers: Vec<(ByteString, ByteString)>,
  pub response_has_body: bool,
  pub response_status: u16,
  pub response_status_text: String,
}

#[derive(Deserialize, Serialize, Debug)]
#[serde(rename_all = "camelCase")]
pub struct CacheMatchRequest {
  pub cache_id: i64,
  pub request_url: String,
  pub request_headers: Vec<(ByteString, ByteString)>,
}

#[derive(Debug, Deserialize, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct CacheMatchResponse(CacheMatchResponseMeta, Option<ResourceId>);

#[derive(Debug, Deserialize, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct CacheMatchResponseMeta {
  pub response_status: u16,
  pub response_status_text: String,
  pub request_headers: Vec<(ByteString, ByteString)>,
  pub response_headers: Vec<(ByteString, ByteString)>,
}

#[derive(Deserialize, Serialize, Debug)]
#[serde(rename_all = "camelCase")]
pub struct CacheDeleteRequest {
  pub cache_id: i64,
  pub request_url: String,
}

#[async_trait]
pub trait Cache: Clone {
  async fn storage_open(&self, cache_name: String) -> Result<i64, AnyError>;
  async fn storage_has(&self, cache_name: String) -> Result<bool, AnyError>;
  async fn storage_delete(&self, cache_name: String) -> Result<bool, AnyError>;

  async fn put(
    &self,
    request_response: CachePutRequest,
  ) -> Result<Option<Rc<dyn Resource>>, AnyError>;
  async fn r#match(
    &self,
    request: CacheMatchRequest,
  ) -> Result<
    Option<(CacheMatchResponseMeta, Option<Rc<dyn Resource>>)>,
    AnyError,
  >;
  async fn delete(&self, request: CacheDeleteRequest)
    -> Result<bool, AnyError>;
}

#[op]
pub async fn op_cache_storage_open<CA>(
  state: Rc<RefCell<OpState>>,
  cache_name: String,
) -> Result<i64, AnyError>
where
  CA: Cache + 'static,
{
  let cache = get_cache::<CA>(&state)?;
  cache.storage_open(cache_name).await
}

#[op]
pub async fn op_cache_storage_has<CA>(
  state: Rc<RefCell<OpState>>,
  cache_name: String,
) -> Result<bool, AnyError>
where
  CA: Cache + 'static,
{
  let cache = get_cache::<CA>(&state)?;
  cache.storage_has(cache_name).await
}

#[op]
pub async fn op_cache_storage_delete<CA>(
  state: Rc<RefCell<OpState>>,
  cache_name: String,
) -> Result<bool, AnyError>
where
  CA: Cache + 'static,
{
  let cache = get_cache::<CA>(&state)?;
  cache.storage_delete(cache_name).await
}

#[op]
pub async fn op_cache_put<CA>(
  state: Rc<RefCell<OpState>>,
  request_response: CachePutRequest,
) -> Result<Option<ResourceId>, AnyError>
where
  CA: Cache + 'static,
{
  let cache = get_cache::<CA>(&state)?;
  match cache.put(request_response).await? {
    Some(_resource) => {
      // let rid = state.borrow_mut().resource_table.add_rc_dyn(resource);
      Ok(Some(1))
    }
    None => Ok(None),
  }
}

#[op]
pub async fn op_cache_match<CA>(
  state: Rc<RefCell<OpState>>,
  request: CacheMatchRequest,
) -> Result<Option<CacheMatchResponse>, AnyError>
where
  CA: Cache + 'static,
{
  let cache = get_cache::<CA>(&state)?;
  match cache.r#match(request).await? {
    Some((meta, None)) => Ok(Some(CacheMatchResponse(meta, None))),
    Some((meta, Some(_resource))) => {
      // let rid = state.borrow_mut().resource_table.add_rc_dyn(resource);
      Ok(Some(CacheMatchResponse(meta, Some(1))))
    }
    None => Ok(None),
  }
}

#[op]
pub async fn op_cache_delete<CA>(
  state: Rc<RefCell<OpState>>,
  request: CacheDeleteRequest,
) -> Result<bool, AnyError>
where
  CA: Cache + 'static,
{
  let cache = get_cache::<CA>(&state)?;
  cache.delete(request).await
}

pub fn get_cache<CA>(state: &Rc<RefCell<OpState>>) -> Result<CA, AnyError>
where
  CA: Cache + 'static,
{
  let mut state = state.borrow_mut();
  if let Some(cache) = state.try_borrow::<CA>() {
    Ok(cache.clone())
  } else {
    let create_cache = state.borrow::<CreateCache<CA>>().clone();
    let cache = create_cache.0();
    state.put(cache);
    Ok(state.borrow::<CA>().clone())
  }
}

#[derive(Clone)]
pub struct CreateCache<C: Cache + 'static>(pub Arc<dyn Fn() -> C>);

pub fn init<CA: Cache + 'static>(
  maybe_create_cache: Option<CreateCache<CA>>,
) -> Extension {
  Extension::builder()
    .js(include_js_files!(
      prefix "deno:ext/cache",
      "01_cache.js",
    ))
    .ops(vec![
      op_cache_storage_open::decl::<CA>(),
      op_cache_storage_has::decl::<CA>(),
      op_cache_storage_delete::decl::<CA>(),
      op_cache_put::decl::<CA>(),
      op_cache_match::decl::<CA>(),
      op_cache_delete::decl::<CA>(),
    ])
    .state(move |state| {
      if let Some(create_cache) = maybe_create_cache.clone() {
        state.put(create_cache);
      }
      Ok(())
    })
    .build()
}

pub fn get_declaration() -> PathBuf {
  PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("lib.deno_cache.d.ts")
}