use std::pin::Pin;
use std::sync::Arc;
use std::task::{Context, Poll};

use failure::*;
use futures::*;
use hyper::Body;
use hyper::http::request::Parts;
use serde_json::{json, Value};

use crate::api2::types::*;
use crate::api_schema::*;
use crate::api_schema::router::*;
use crate::backup::*;
use crate::tools;

use super::environment::*;

pub struct UploadChunk {
    stream: Body,
    store: Arc<DataStore>,
    digest: [u8; 32],
    size: u32,
    encoded_size: u32,
    raw_data: Option<Vec<u8>>,
}

impl UploadChunk {
    pub fn new(stream: Body,  store: Arc<DataStore>, digest: [u8; 32], size: u32, encoded_size: u32) -> Self {
        Self { stream, store, size, encoded_size, raw_data: Some(vec![]), digest }
    }
}

impl Future for UploadChunk {
    type Output = Result<([u8; 32], u32, u32, bool), Error>;

    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
        let this = self.get_mut();

        let err: Error = loop {
            match ready!(Pin::new(&mut this.stream).poll_next(cx)) {
                Some(Err(err)) => return Poll::Ready(Err(Error::from(err))),
                Some(Ok(input)) => {
                    if let Some(ref mut raw_data) = this.raw_data {
                        if (raw_data.len() + input.len()) > (this.encoded_size as usize) {
                            break format_err!("uploaded chunk is larger than announced.");
                        }
                        raw_data.extend_from_slice(&input);
                    } else {
                        break format_err!("poll upload chunk stream failed - already finished.");
                    }
                }
                None => {
                    if let Some(raw_data) = this.raw_data.take() {
                        if raw_data.len() != (this.encoded_size as usize) {
                            break format_err!("uploaded chunk has unexpected size.");
                        }

                        let (is_duplicate, compressed_size) = match proxmox::tools::try_block! {
                            let mut chunk = DataChunk::from_raw(raw_data, this.digest)?;

                            chunk.verify_unencrypted(this.size as usize)?;

                            // always comput CRC at server side
                            chunk.set_crc(chunk.compute_crc());

                            this.store.insert_chunk(&chunk)
                        } {
                            Ok(res) => res,
                            Err(err) => break err,
                        };

                        return Poll::Ready(Ok((this.digest, this.size, compressed_size as u32, is_duplicate)))
                    } else {
                        break format_err!("poll upload chunk stream failed - already finished.");
                    }
                }
            }
        };
        Poll::Ready(Err(err))
    }
}

pub fn api_method_upload_fixed_chunk() -> ApiAsyncMethod {
    ApiAsyncMethod::new(
        upload_fixed_chunk,
        ObjectSchema::new("Upload a new chunk.")
            .required("wid", IntegerSchema::new("Fixed writer ID.")
                      .minimum(1)
                      .maximum(256)
            )
            .required("digest", CHUNK_DIGEST_SCHEMA.clone())
            .required("size", IntegerSchema::new("Chunk size.")
                      .minimum(1)
                      .maximum(1024*1024*16)
            )
            .required("encoded-size", IntegerSchema::new("Encoded chunk size.")
                      .minimum((std::mem::size_of::<DataChunkHeader>() as isize)+1)
                      .maximum(1024*1024*16+(std::mem::size_of::<EncryptedDataChunkHeader>() as isize))
            )
    )
}

fn upload_fixed_chunk(
    _parts: Parts,
    req_body: Body,
    param: Value,
    _info: &ApiAsyncMethod,
    rpcenv: Box<dyn RpcEnvironment>,
) -> Result<BoxFut, Error> {

    let wid = tools::required_integer_param(&param, "wid")? as usize;
    let size = tools::required_integer_param(&param, "size")? as u32;
    let encoded_size = tools::required_integer_param(&param, "encoded-size")? as u32;

    let digest_str = tools::required_string_param(&param, "digest")?;
    let digest = proxmox::tools::hex_to_digest(digest_str)?;

    let env: &BackupEnvironment = rpcenv.as_ref();

    let upload = UploadChunk::new(req_body, env.datastore.clone(), digest, size, encoded_size);

    let resp = upload
        .then(move |result| {
            let env: &BackupEnvironment = rpcenv.as_ref();

            let result = result.and_then(|(digest, size, compressed_size, is_duplicate)| {
                env.register_fixed_chunk(wid, digest, size, compressed_size, is_duplicate)?;
                let digest_str = proxmox::tools::digest_to_hex(&digest);
                env.debug(format!("upload_chunk done: {} bytes, {}", size, digest_str));
                Ok(json!(digest_str))
            });

            future::ok(env.format_response(result))
        });

    Ok(Box::new(resp))
}

pub fn api_method_upload_dynamic_chunk() -> ApiAsyncMethod {
    ApiAsyncMethod::new(
        upload_dynamic_chunk,
        ObjectSchema::new("Upload a new chunk.")
            .required("wid", IntegerSchema::new("Dynamic writer ID.")
                      .minimum(1)
                      .maximum(256)
            )
            .required("digest", CHUNK_DIGEST_SCHEMA.clone())
            .required("size", IntegerSchema::new("Chunk size.")
                      .minimum(1)
                      .maximum(1024*1024*16)
            )
            .required("encoded-size", IntegerSchema::new("Encoded chunk size.")
                      .minimum((std::mem::size_of::<DataChunkHeader>() as isize) +1)
                      .maximum(1024*1024*16+(std::mem::size_of::<EncryptedDataChunkHeader>() as isize))
            )
    )
}

fn upload_dynamic_chunk(
    _parts: Parts,
    req_body: Body,
    param: Value,
    _info: &ApiAsyncMethod,
    rpcenv: Box<dyn RpcEnvironment>,
) -> Result<BoxFut, Error> {

    let wid = tools::required_integer_param(&param, "wid")? as usize;
    let size = tools::required_integer_param(&param, "size")? as u32;
    let encoded_size = tools::required_integer_param(&param, "encoded-size")? as u32;

    let digest_str = tools::required_string_param(&param, "digest")?;
    let digest = proxmox::tools::hex_to_digest(digest_str)?;

    let env: &BackupEnvironment = rpcenv.as_ref();

    let upload = UploadChunk::new(req_body, env.datastore.clone(), digest, size, encoded_size);

    let resp = upload
        .then(move |result| {
            let env: &BackupEnvironment = rpcenv.as_ref();

            let result = result.and_then(|(digest, size, compressed_size, is_duplicate)| {
                env.register_dynamic_chunk(wid, digest, size, compressed_size, is_duplicate)?;
                let digest_str = proxmox::tools::digest_to_hex(&digest);
                env.debug(format!("upload_chunk done: {} bytes, {}", size, digest_str));
                Ok(json!(digest_str))
            });

            future::ok(env.format_response(result))
        });

    Ok(Box::new(resp))
}

pub fn api_method_upload_speedtest() -> ApiAsyncMethod {
    ApiAsyncMethod::new(
        upload_speedtest,
        ObjectSchema::new("Test uploadf speed.")
    )
}

fn upload_speedtest(
    _parts: Parts,
    req_body: Body,
    _param: Value,
    _info: &ApiAsyncMethod,
    rpcenv: Box<dyn RpcEnvironment>,
) -> Result<BoxFut, Error> {

    let resp = req_body
        .map_err(Error::from)
        .try_fold(0, |size: usize, chunk| {
            let sum = size + chunk.len();
            //println!("UPLOAD {} bytes, sum {}", chunk.len(), sum);
            future::ok::<usize, Error>(sum)
        })
        .then(move |result| {
            match result {
                Ok(size) => {
                    println!("UPLOAD END {} bytes", size);
                }
                Err(err) => {
                    println!("Upload error: {}", err);
                }
            }
            let env: &BackupEnvironment = rpcenv.as_ref();
            future::ok(env.format_response(Ok(Value::Null)))
        });

    Ok(Box::new(resp))
}

pub fn api_method_upload_blob() -> ApiAsyncMethod {
    ApiAsyncMethod::new(
        upload_blob,
        ObjectSchema::new("Upload binary blob file.")
            .required("file-name", crate::api2::types::BACKUP_ARCHIVE_NAME_SCHEMA.clone())
            .required("encoded-size", IntegerSchema::new("Encoded blob size.")
                      .minimum((std::mem::size_of::<DataBlobHeader>() as isize) +1)
                      .maximum(1024*1024*16+(std::mem::size_of::<EncryptedDataBlobHeader>() as isize))
            )
    )
}

fn upload_blob(
    _parts: Parts,
    req_body: Body,
    param: Value,
    _info: &ApiAsyncMethod,
    rpcenv: Box<dyn RpcEnvironment>,
) -> Result<BoxFut, Error> {

    let file_name = tools::required_string_param(&param, "file-name")?.to_owned();
    let encoded_size = tools::required_integer_param(&param, "encoded-size")? as usize;


    let env: &BackupEnvironment = rpcenv.as_ref();

    if !file_name.ends_with(".blob") {
        bail!("wrong blob file extension: '{}'", file_name);
    }

    let env2 = env.clone();
    let env3 = env.clone();

    let resp = req_body
        .map_err(Error::from)
        .try_fold(Vec::new(), |mut acc, chunk| {
            acc.extend_from_slice(&*chunk);
            future::ok::<_, Error>(acc)
        })
        .and_then(move |data| async move {
            if encoded_size != data.len() {
                bail!("got blob with unexpected length ({} != {})", encoded_size, data.len());
            }

            env2.add_blob(&file_name, data)?;

            Ok(())
        })
        .and_then(move |_| {
            future::ok(env3.format_response(Ok(Value::Null)))
        })
        ;

    Ok(Box::new(resp))
}