use crate::error::LibError;

use num_enum::{IntoPrimitive, TryFromPrimitive};

#[derive(Debug, Clone, Copy)]
pub struct Status {
    status_code: StatusCode,
    reply_type: ReplyType,
    second_digit: u8,
}

#[derive(Debug, Clone, Copy, Eq, PartialEq, TryFromPrimitive, IntoPrimitive)]
#[num_enum(error_type(name = LibError, constructor = LibError::status_out_of_range))]
#[repr(u8)]
pub enum ReplyType {
    Input = 1,
    Success,
    Redirect,
    TempFail,
    PermFail,
    Auth,
}

#[derive(Debug, Clone, Copy, Eq, PartialEq, TryFromPrimitive, IntoPrimitive)]
#[num_enum(error_type(name = LibError, constructor = LibError::status_out_of_range))]
#[repr(u8)]
pub enum StatusCode {
    Input = 10,
    InputSensitive = 11,

    Success = 20,

    TempRedirect = 30,
    PermRedirect = 31,

    TempFail = 40,
    ServerUnavailable = 41,
    CgiError = 42,
    ProxyError = 43,
    SlowDown = 44,

    PermFail = 50,
    NotFound = 51,
    Gone = 52,
    ProxyRequestRefused = 53,
    BadRequest = 59,

    ClientCerts = 60,
    CertNotAuthorized = 61,
    CertNotValid = 62,

    // 1..6 first digit range check is still
    // covered by conversion into ReplyType
    // (see Status::parse_status)
    #[num_enum(catch_all)]
    Unknown(u8),
}

const ASCII_ZERO: u8 = 48; // '0'

impl Status {
    pub fn parse_status(buf: &[u8]) -> Result<Self, LibError> {
        // simple decimal digit conversion
        // '2' - '0' = 50 - 48 = 2 (from byte '2' to uint 2)
        let first = buf[0] - ASCII_ZERO;
        let second = buf[1] - ASCII_ZERO;

        let code = first * 10 + second;

        Ok(Status {
            // get enum item for 2-digit status code
            status_code: StatusCode::try_from_primitive(code)?,
            // get enum entry for first digit
            reply_type: ReplyType::try_from_primitive(first)?,
            // provide separate field for the 2nd digit
            second_digit: second,
        })
    }

    pub fn status_code(self: &Self) -> StatusCode {
        self.status_code
    }

    pub fn num(self: &Self) -> u8 {
        self.status_code.into()
    }

    pub fn reply_type(self: &Self) -> ReplyType {
        self.reply_type
    }

    pub fn second_digit(self: &Self) -> u8 {
        self.second_digit
    }
}