use std::{error::Error, fmt};

pub mod basic_types {
    pub use rust_decimal::Decimal;

    pub type Int = i64;
    pub type TagNum = u16;
    pub type SeqNum = u64;
    pub type NumInGroup = u8;
    pub type DayOfMonth = u8;

    pub type Float = Decimal;
    pub type Qty = Float;
    pub type Price = Float;
    pub type PriceOffset = Float;
    pub type Amt = Float;
    pub type Percentage = Float;

    pub type Boolean = bool;

    pub type Char = u8;
    pub type MultipleCharValue = Vec<Char>;

    pub type Str = Vec<u8>;
    pub type MultipleStringValue = Vec<Vec<u8>>;

    pub use crate::country::Country;
    pub use crate::currency::Currency;
    pub type Exchange = [u8; 4];
    pub type MonthYear = Vec<u8>;
    pub type Language = [u8; 2];

    pub type UtcTimestamp = Vec<u8>;
    pub type UtcTimeOnly = Vec<u8>;
    pub type UtcDateOnly = (u16, u8, u8);

    pub type LocalMktTime = u64;
    pub type LocalMktDate = (u16, u8, u8);

    pub type TzTimestamp = Vec<u8>;
    pub type TzTimeOnly = Vec<u8>;

    pub type Length = u16;
    pub type Data = Vec<u8>;
    pub type XmlData = Data;

    pub type Tenor = Vec<u8>;
}

pub use basic_types::*;

#[derive(Debug)]
pub enum DeserializeError {
    // TODO: enum maybe?
    GarbledMessage(String),
    Logout,
    Reject {
        msg_type: Vec<u8>,
        seq_num: SeqNum,
        tag: Option<TagNum>,
        reason: RejectReason,
    },
}

impl fmt::Display for DeserializeError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            DeserializeError::GarbledMessage(reason) => write!(f, "garbled message: {}", reason),
            DeserializeError::Logout => write!(f, "MsgSeqNum missing, force logout"),
            DeserializeError::Reject {
                msg_type,
                seq_num,
                tag,
                reason,
            } => write!(
                f,
                "message {:?}/{} rejected: {:?} (tag={:?})",
                msg_type, seq_num, reason, tag
            ),
        }
    }
}

impl Error for DeserializeError {}

// TODO:
// enum GarbledReason

#[derive(Debug)]
pub enum RejectReason {
    InvalidTagNumber,
    RequiredTagMissing,
    TagNotDefinedForThisMessageType,
    UndefinedTag,
    TagSpecifiedWithoutAValue,
    ValueIsIncorrect,
    IncorrectDataFormatForValue,
    DecryptionProblem,
    SignatureProblem,
    CompIDProblem,
    SendingTimeAccuracyProblem,
    InvalidMsgType,
    XMLValidationError,
    TagAppearsMoreThanOnce,
    TagSpecifiedOutOfRequiredOrder,
    RepeatingGroupFieldsOutOfOrder,
    IncorrectNumInGroupCountForRepeatingGroup,
    Non,
    Invalid,
    Other,
    //0	= Invalid Tag Number[InvalidTagNumber]
    //1	= Required Tag Missing[RequiredTagMissing]
    //2	= Tag not defined for this message type[TagNotDefinedForThisMessageType]
    //3	= Undefined tag[UndefinedTag]
    //4	= Tag specified without a value[TagSpecifiedWithoutAValue]
    //5	= Value is incorrect (out of range) for this tag[ValueIsIncorrect]
    //6	= Incorrect data format for value[IncorrectDataFormatForValue]
    //7	= Decryption problem[DecryptionProblem]
    //8	= Signature problem[SignatureProblem]
    //9	= CompID problem[CompIDProblem]
    //10	= SendingTime Accuracy Problem[SendingTimeAccuracyProblem]
    //11	= Invalid MsgType[InvalidMsgType]
    //12	= XML Validation Error[XMLValidationError]
    //13	= Tag appears more than once[TagAppearsMoreThanOnce]
    //14	= Tag specified out of required order[TagSpecifiedOutOfRequiredOrder]
    //15	= Repeating group fields out of order[RepeatingGroupFieldsOutOfOrder]
    //16	= Incorrect NumInGroup count for repeating group[IncorrectNumInGroupCountForRepeatingGroup]
    //17	= Non Data value includes field delimiter (<SOH> character)[Non]
    //18	= Invalid/Unsupported Application Version[Invalid]
    //99	= Other[Other]
}

// ----------------------------------------------------------------------------

pub fn parse_u16(input: &[u8]) -> Result<u16, &[u8]> {
    let i = input;

    if i.len() == 0 {
        return Err(input);
    }

    let mut value: u16 = 0;
    for i in input {
        match i {
            b'0'..=b'9' => {
                if let Some(v) = value.checked_mul(10).and_then(|v| v.checked_add(*i as u16)) {
                    value = v;
                } else {
                    return Err(input);
                }
            }
            _ => return Err(input),
        }
    }
    Ok(value)
}

/*






fn serialize_int(&self);
fn serialize_tag_num(&self);
fn serialize_seq_num(&self);
fn serialize_num_in_group(&self);
fn serialize_dat_of_month(&self);

fn serialize_float(&self);
fn serialize_qty(&self);
fn serialize_price(&self);
fn serialize_price_offset(&self);
fn serialize_percentage(&self);

fn serialize_boolean(&self);

fn serialize_char(&self);
fn serialize_multiple_char_value(&self);

fn serialize_string(&self);
fn serialize_multiple_string_value(&self);

fn serialize_country(&self);
fn serialize_currency(&self);
fn serialize_exchange(&self);
fn serialize_month_year(&self);
fn serialize_language(&self);

fn serialize_utc_timestamp(&self);
fn serialize_utc_time_only(&self);
fn serialize_utc_data_only(&self);

fn serialize_local_mkt_time(&self);
fn serialize_local_mkt_data(&self);

fn serialize_tz_timestamp(&self);
fn serialize_tz_timeonly(&self);

fn serialize_length(&self);
fn serialize_data(&self);
fn serialize_xml(&self);

fn serialize_tenor(&self);
*/