use crate::base::{ErrorCode, HasErrorCode, ParameterValueRaw};
use snafu::ensure;
use std::io::{Read, Write};
use crate::{
    error, Endian, ErrorCodeReaderExt, ErrorCodeWriterExt,
    HasFixedCommandId, IsRequest, IsResponse, IsValidResponseFor,
    MessageExt, ParameterValueReaderExt, ParameterValueWriteMode,
    ParameterValueWriterExt, ReadExt, ReadFromPayload, Result,
    TryFromResponse, WithFixedPayloadLength, WriteExt,
};

#[derive(Clone, Debug, PartialEq)]
pub struct Request;

impl IsRequest for Request {
    type Response = Response;
}

impl From<Request> for super::Request {
    fn from(m: Request) -> Self {
        super::Request::QueryJobParameters(m)
    }
}

impl WithFixedPayloadLength for Request {
    const FIXED_PAYLOAD_LENGTH: u16 = 0u16;
}

impl HasFixedCommandId for Request {
    const COMMAND_ID: u16 = 0x2806;
}

impl MessageExt for Request {
    fn payload_length(&self) -> u16 {
        Self::FIXED_PAYLOAD_LENGTH
    }

    fn write_payload(&self, _w: &mut Write) -> Result<()> {
        Ok(())
    }
}

impl ReadFromPayload for Request {
    fn read_from_payload<R: Read>(
        _r: &mut R,
        payload_length: u16,
    ) -> Result<Self> {
        Self::verify_payload_length(
            payload_length,
            "query_job_parameters_request",
        )?;
        Ok(Self {})
    }
}

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

    #[test]
    fn write_to() {
        let mut buffer = Vec::new();
        let options: u8 = 0x45;
        let sequence: u8 = 0x93;

        let message = Request {};
        message.write_to(&mut buffer, options, sequence).unwrap();
        assert_eq!(
            buffer,
            [
                0x45, // options
                0x93, // sequence
                0x06, // command lower byte
                0x28, // command upper byte
                0x00, // length lower byte
                0x00, // length upper byte
            ]
        );
    }
    #[test]
    fn read_from_payload() {
        let buffer = vec![];
        let len = buffer.len() as u16;
        let message =
            Request::read_from_payload(&mut buffer.as_slice(), len)
                .unwrap();
        assert_eq!(message, Request {});
    }
}

#[derive(Clone, Debug, PartialEq)]
pub struct Response {
    pub error: ErrorCode,
    pub values: Vec<ParameterValueRaw>,
}

impl IsResponse for Response {
    type Request = Request;
}

impl IsValidResponseFor for Response {
    fn is_valid_response_for(&self, _request: &Request) -> bool {
        true
    }
}

impl HasErrorCode for Response {
    fn error_code(&self) -> ErrorCode {
        self.error
    }
}

impl TryFromResponse for Response {
    fn try_from_response(r: super::Response) -> Result<Self> {
        if let super::Response::QueryJobParameters(r) = r {
            Ok(r)
        } else {
            error::UnexpectedResponseType.fail()?
        }
    }
}

impl From<Response> for super::Response {
    fn from(m: Response) -> Self {
        super::Response::QueryJobParameters(m)
    }
}

impl Response {
    const ADDITIONAL_FIXED_PAYLOAD_LENGTH: u16 =
        ErrorCode::FIXED_PAYLOAD_LENGTH + u16::FIXED_PAYLOAD_LENGTH;

    fn verify_payload_length(received: u16, required: u16) -> Result<()> {
        ensure!(
            required == received,
            error::InvalidPayloadLength {
                message_type: "query_job_parameters_response",
                received,
                required
            }
        );
        Ok(())
    }
}

impl HasFixedCommandId for Response {
    const COMMAND_ID: u16 = 0x2807;
}

impl MessageExt for Response {
    fn payload_length(&self) -> u16 {
        Self::ADDITIONAL_FIXED_PAYLOAD_LENGTH
            + ParameterValueRaw::FIXED_PAYLOAD_LENGTH
                * self.values.len() as u16
    }

    fn write_payload(&self, w: &mut Write) -> Result<()> {
        w.write_error_code(self.error)?;
        w.write_u16::<Endian>(self.values.len() as u16)?;
        for value in &self.values {
            w.write_parameter_value(
                value,
                &ParameterValueWriteMode::TypeAndValue,
            )?;
        }
        Ok(())
    }
}

impl ReadFromPayload for Response {
    fn read_from_payload<R: Read>(
        r: &mut R,
        payload_length: u16,
    ) -> Result<Self> {
        let error = r.read_error_code()?;
        let count = r.read_u16::<Endian>()?;
        let required_payload_length = Self::ADDITIONAL_FIXED_PAYLOAD_LENGTH
            + count * ParameterValueRaw::FIXED_PAYLOAD_LENGTH;

        Self::verify_payload_length(
            payload_length,
            required_payload_length,
        )?;
        let mut values = Vec::new();
        for _ in 0..count {
            values.push(r.read_parameter_value()?);
        }
        Ok(Self { error, values })
    }
}

#[cfg(test)]
mod test_response {
    use super::*;
    use crate::base::ModuleChannelReference;

    #[test]
    fn write_to_empty() {
        let mut buffer = Vec::new();
        let options: u8 = 0x45;
        let sequence: u8 = 0x93;

        let values = Vec::new();

        let message = Response {
            error: ErrorCode::InvalidState, // 0x0107
            values,
        };
        message.write_to(&mut buffer, options, sequence).unwrap();
        assert_eq!(
            buffer,
            [
                0x45, // options
                0x93, // sequence
                0x07, // command lower byte
                0x28, // command upper byte
                0x04, // length lower byte
                0x00, // length upper byte
                0x07, // error lower byte
                0x01, // error upper byte
                0x00, // value count lower byte
                0x00, // value count upper byte
            ]
        );
    }
    #[test]
    fn write_to_single_boolean() {
        let mut buffer = Vec::new();
        let options: u8 = 0x45;
        let sequence: u8 = 0x93;

        let error = ErrorCode::InvalidState;
        let values = vec![true.into()];

        let length = {
            let fixed = 4u16;
            let per_value = 9u16;
            let value_count = 1u16;
            fixed + per_value * value_count
        };
        assert_eq!(length, 0x000D);
        assert_eq!(0x000D, 13);

        let message = Response { error, values };
        message.write_to(&mut buffer, options, sequence).unwrap();
        assert_eq!(
            buffer,
            vec![
                0x45, // options
                0x93, // sequence
                0x07, // command lower byte
                0x28, // command upper byte
                0x0D, // length lower byte
                0x00, // length upper byte
                0x07, // error lower byte
                0x01, // error upper byte
                0x01, // value count lower byte
                0x00, // value count upper byte
                0x00, // value 0 type
                0x01, // value 0 byte 0
                0x00, // value 0 byte 1
                0x00, // value 0 byte 2
                0x00, // value 0 byte 3
                0x00, // value 0 byte 4
                0x00, // value 0 byte 5
                0x00, // value 0 byte 6
                0x00, // value 0 byte 7
            ]
        );
    }
    #[test]
    fn write_to_three_items() {
        use crate::base::ParameterValue;

        let mut buffer = Vec::new();
        let options: u8 = 0x45;
        let sequence: u8 = 0x93;

        let module_id = 0x4532;
        let channel_id = 0x1921;

        let error = ErrorCode::InvalidState;
        let values = vec![
            0x1234u16.into(),
            true.into(),
            ParameterValue::UInt8Channel(ModuleChannelReference {
                module_id,
                channel_id,
            }),
        ];

        let length = {
            let fixed = 4u16;
            let per_value = 9u16;
            let value_count = 3u16;
            fixed + per_value * value_count
        };
        assert_eq!(length, 0x001F);
        assert_eq!(0x001F, 31);

        let message = Response { error, values };
        message.write_to(&mut buffer, options, sequence).unwrap();
        assert_eq!(
            buffer,
            vec![
                0x45, // options
                0x93, // sequence
                0x07, // command lower byte
                0x28, // command upper byte
                0x1F, // length lower byte
                0x00, // length upper byte
                0x07, // error lower byte
                0x01, // error upper byte
                0x03, // value count lower byte
                0x00, // value count upper byte
                0x06, // value 0 type
                0x34, // value 0 byte 0
                0x12, // value 0 byte 1
                0x00, // value 0 byte 2
                0x00, // value 0 byte 3
                0x00, // value 0 byte 4
                0x00, // value 0 byte 5
                0x00, // value 0 byte 6
                0x00, // value 0 byte 7
                0x00, // value 1 type
                0x01, // value 1 byte 0
                0x00, // value 1 byte 1
                0x00, // value 1 byte 2
                0x00, // value 1 byte 3
                0x00, // value 1 byte 4
                0x00, // value 1 byte 5
                0x00, // value 1 byte 6
                0x00, // value 1 byte 7
                0x15, // value 2 type
                0x21, // value 2 byte 0
                0x19, // value 2 byte 1
                0x32, // value 2 byte 2
                0x45, // value 2 byte 3
                0x00, // value 2 byte 4
                0x00, // value 2 byte 5
                0x00, // value 2 byte 6
                0x00, // value 2 byte 7
            ]
        );
    }
    #[test]
    fn from_payload_empty() {
        let buffer = vec![
            0x07, // error lower byte
            0x01, // error upper byte
            0x00, // value count lower byte
            0x00, // value count upper byte
        ];
        let len = buffer.len() as u16;
        let message =
            Response::read_from_payload(&mut buffer.as_slice(), len)
                .unwrap();
        let values = Vec::new();
        assert_eq!(
            message,
            Response {
                error: ErrorCode::InvalidState,
                values,
            }
        );
    }
    #[test]
    fn from_payload_single_bool() {
        let buffer = vec![
            0x07, // error lower byte
            0x01, // error upper byte
            0x01, // value count lower byte
            0x00, // value count upper byte
            0x00, // value 0 type
            0x01, // value 0 byte 0
            0x00, // value 0 byte 1
            0x00, // value 0 byte 2
            0x00, // value 0 byte 3
            0x00, // value 0 byte 4
            0x00, // value 0 byte 5
            0x00, // value 0 byte 6
            0x00, // value 0 byte 7
        ];
        let len = buffer.len() as u16;
        let message =
            Response::read_from_payload(&mut buffer.as_slice(), len)
                .unwrap();

        let error = ErrorCode::InvalidState;
        let values = vec![true.into()];

        assert_eq!(message, Response { error, values });
    }
    #[test]
    fn read_from_three_items() {
        use crate::base::ParameterValue;

        let buffer = vec![
            0x07, // error lower byte
            0x01, // error upper byte
            0x03, // value count lower byte
            0x00, // value count upper byte
            0x06, // value 0 type
            0x34, // value 0 byte 0
            0x12, // value 0 byte 1
            0x00, // value 0 byte 2
            0x00, // value 0 byte 3
            0x00, // value 0 byte 4
            0x00, // value 0 byte 5
            0x00, // value 0 byte 6
            0x00, // value 0 byte 7
            0x00, // value 1 type
            0x01, // value 1 byte 0
            0x00, // value 1 byte 1
            0x00, // value 1 byte 2
            0x00, // value 1 byte 3
            0x00, // value 1 byte 4
            0x00, // value 1 byte 5
            0x00, // value 1 byte 6
            0x00, // value 1 byte 7
            0x15, // value 2 type
            0x21, // value 2 byte 0
            0x19, // value 2 byte 1
            0x32, // value 2 byte 2
            0x45, // value 2 byte 3
            0x00, // value 2 byte 4
            0x00, // value 2 byte 5
            0x00, // value 2 byte 6
            0x00, // value 2 byte 7
        ];
        let len = buffer.len() as u16;
        let message =
            Response::read_from_payload(&mut buffer.as_slice(), len)
                .unwrap();

        let module_id = 0x4532;
        let channel_id = 0x1921;

        let error = ErrorCode::InvalidState;
        let values = vec![
            0x1234u16.into(),
            true.into(),
            ParameterValue::UInt8Channel(ModuleChannelReference {
                module_id,
                channel_id,
            }),
        ];

        assert_eq!(message, Response { error, values });
    }
}