use std::iter::IntoIterator;
use vec1::Vec1;
use soft_ascii_string::SoftAsciiChar;

use internals::error::EncodingError;
use internals::encoder::{EncodableInHeader, EncodingWriter};
use ::{ HeaderTryFrom, HeaderTryInto};
use ::error::ComponentCreationError;

use super::Mailbox;

#[derive(Debug, Hash, Eq, PartialEq, Clone)]
pub struct OptMailboxList( pub Vec<Mailbox> );

#[derive(Debug, Hash, Eq, PartialEq, Clone)]
pub struct MailboxList( pub Vec1<Mailbox> );

impl MailboxList {
    pub fn from_single( m: Mailbox ) -> Self {
        MailboxList( Vec1::new( m ) )
    }
}

impl IntoIterator for MailboxList {
    type Item = <Vec1<Mailbox> as IntoIterator>::Item;
    type IntoIter = <Vec1<Mailbox> as IntoIterator>::IntoIter;

    fn into_iter(self) -> Self::IntoIter {
        self.0.into_iter()
    }
}



impl EncodableInHeader for  OptMailboxList {

    fn encode(&self, handle: &mut EncodingWriter) -> Result<(), EncodingError> {
       encode_list( self.0.iter(), handle )
    }

    fn boxed_clone(&self) -> Box<EncodableInHeader> {
        Box::new(self.clone())
    }
}

//impl HeaderTryFrom<Mailbox> for OptMailboxList {
//    fn try_from( mbox: Mailbox ) -> Result<Self> {
//        Ok( OptMailboxList( vec![ mbox ] ) )
//    }
//}

//impl<T> HeaderTryFrom<T> for MailboxList
//    where T: HeaderTryInto<Mailbox>
//{
//    fn try_from( mbox: T ) -> Result<Self> {
//        let mbox = mbox.try_into()?;
//        Ok( MailboxList( Vec1::new( mbox ) ) )
//    }
//}

//TODO-RUST-RFC: allow conflicting wildcard implementations if priority is specified
// if done then we can implement it for IntoIterator instead of Vec and slice
impl<T> HeaderTryFrom<Vec<T>> for MailboxList
    where T: HeaderTryInto<Mailbox>
{
    fn try_from(vec: Vec<T>) -> Result<Self, ComponentCreationError> {
        try_from_into_iter( vec )
    }
}

fn try_from_into_iter<IT>( mboxes: IT ) -> Result<MailboxList, ComponentCreationError>
    where IT: IntoIterator, IT::Item: HeaderTryInto<Mailbox>
{
    let mut iter = mboxes.into_iter();
    let mut vec = if let Some( first) = iter.next() {
        Vec1::new( first.try_into()? )
    } else {
        //TODO chain vec1 Size0Error
        return Err(ComponentCreationError::new("MailboxList"));
    };
    for mbox in iter {
        vec.push( mbox.try_into()? );
    }
    Ok( MailboxList( vec ) )
}

macro_rules! impl_header_try_from_array {
    (_MBoxList 0) => ();
    (_MBoxList $len:tt) => (
        impl<T> HeaderTryFrom<[T; $len]> for MailboxList
            where T: HeaderTryInto<Mailbox>
        {
            fn try_from( vec: [T; $len] ) -> Result<Self, ComponentCreationError> {
                //due to only supporting arrays halfheartedly for now
                let heapified: Box<[T]> = Box::new(vec);
                let vecified: Vec<_> = heapified.into();
                try_from_into_iter( vecified )
            }
        }
    );
    (_OptMBoxList $len:tt) => (
        impl<T> HeaderTryFrom<[T; $len]> for OptMailboxList
            where T: HeaderTryInto<Mailbox>
        {
            fn try_from( vec: [T; $len] ) -> Result<Self, ComponentCreationError> {
                let heapified: Box<[T]> = Box::new(vec);
                let vecified: Vec<_> = heapified.into();
                let mut out = Vec::new();
                for ele in vecified.into_iter() {
                    out.push( ele.try_into()? );
                }
                Ok( OptMailboxList( out ) )
            }
        }
    );
    ($($len:tt)*) => ($(
        impl_header_try_from_array!{ _MBoxList $len }
        impl_header_try_from_array!{ _OptMBoxList $len }
    )*);
}

impl_header_try_from_array! {
     0  1  2  3  4  5  6  7  8  9
    10 11 12 13 14 15 16 17 18 19
    20 21 22 23 24 25 26 27 28 29
    30 31 32
}

//TODO also implement for phrase list
macro_rules! impl_header_try_from_tuple {
    (_MBoxList []) => (
        compiler_error!("mailbox list needs at last one element")
    );
    (_MBoxList [ $($vs:ident),* ]) => (
        impl< $($vs),* > HeaderTryFrom<( $($vs,)* )> for MailboxList
            where $($vs: HeaderTryInto<Mailbox>),*
        {
            #[allow(non_snake_case)]
            fn try_from( ($($vs,)*): ($($vs,)*) ) -> Result<Self, ComponentCreationError> {
                // we use the type names as variable names,
                // not nice but it works
                //let ($($vs),*) = src;
                let mut out = Vec::new();
                $(
                    let $vs = $vs.try_into()?;
                    out.push($vs);
                )*
                Ok( MailboxList(
                    //UNWRAP_SAFE: len 0 is not implemented with the macro
                    $crate::vec1::Vec1::try_from_vec(out).unwrap()
                ) )
            }
        }
    );
    (_OptMBoxList [$($vs:ident),*]) => (
        impl< $($vs),* > HeaderTryFrom<( $($vs,)* )> for OptMailboxList
            where $($vs: HeaderTryInto<Mailbox>),*
        {
            #[allow(non_snake_case)]
            fn try_from( ($($vs,)*): ($($vs,)*) ) -> Result<Self, ComponentCreationError> {
                // we use the type names as variable names,
                // not nice but it works
                //let ($($vs),*) = src;
                let mut out = Vec::new();
                $(
                    let $vs = $vs.try_into()?;
                    out.push($vs);
                )*
                Ok( OptMailboxList( out ) )
            }
        }
    );
    ([]) => ();
    ([$first_vs:ident $(, $vs:ident)*]) => (
        impl_header_try_from_tuple!{ _MBoxList [$first_vs $(, $vs)* ] }
        impl_header_try_from_tuple!{ _OptMBoxList [$first_vs $(, $vs)*] }
        impl_header_try_from_tuple!{ [$($vs),*] }
    );
}

impl_header_try_from_tuple! {
    [
        A0,  A1,  A2,  A3,  A4,  A5,  A6,  A7,
        A8,  A9,  A10, A11, A12, A13, A14, A15,
        A16, A17, A18, A19, A20, A21, A22, A23,
        A24, A25, A26, A27, A28, A29, A30, A31
    ]
}

impl<T> HeaderTryFrom<Vec<T>> for OptMailboxList
    where T: HeaderTryInto<Mailbox>
{
    fn try_from(vec: Vec<T>) -> Result<Self, ComponentCreationError> {
        let mut out = Vec::new();
        for ele in vec.into_iter() {
            out.push( ele.try_into()? );
        }
        Ok( OptMailboxList( out ) )
    }
}

impl EncodableInHeader for  MailboxList {

    fn encode(&self, handle: &mut EncodingWriter) -> Result<(), EncodingError> {
        encode_list( self.0.iter(), handle )
    }

    fn boxed_clone(&self) -> Box<EncodableInHeader> {
        Box::new(self.clone())
    }
}

fn encode_list<'a, I>(list_iter: I, handle: &mut EncodingWriter) -> Result<(), EncodingError>
    where I: Iterator<Item=&'a Mailbox>
{
    sep_for!{ mailbox in list_iter;
        sep {
            handle.write_char( SoftAsciiChar::from_unchecked(',') )?;
            handle.write_fws();
        };
        mailbox.encode( handle )?;
    }
    Ok( () )
}

deref0!{ +mut OptMailboxList => Vec<Mailbox> }
deref0!{ +mut MailboxList => Vec1<Mailbox> }

#[cfg(test)]
mod test {
    use ::header_components::{ Mailbox, Email, Phrase };
    use super::*;


    ec_test! { empty_list, {
        OptMailboxList( Vec::new() )
    } => ascii => [

    ]}

    ec_test! { single, {
        MailboxList( vec1![
            Mailbox {
                display_name: Some( Phrase::try_from( "hy ho" )? ),
                email: Email::try_from( "ran@dom" )?
            },
        ] )
    } => ascii => [
        Text "hy",
        MarkFWS,
        Text " ho",
        MarkFWS,
        Text " <",
        MarkFWS,
        Text "ran",
        MarkFWS,
        Text "@",
        MarkFWS,
        Text "dom",
        MarkFWS,
        Text ">"
    ]}

    ec_test! { multiple, {
         MailboxList( vec1![
            Mailbox {
                display_name: Some( Phrase::try_from( "hy ho" )? ),
                email: Email::try_from( "nar@mod" )?
            },
            Mailbox {
                display_name: None,
                email: Email::try_from( "ran@dom" )?
            }
        ] )
    } => ascii => [
        Text "hy",
        MarkFWS,
        Text " ho",
        MarkFWS,
        Text " <",
        MarkFWS,
        Text "nar",
        MarkFWS,
        Text "@",
        MarkFWS,
        Text "mod",
        MarkFWS,
        Text ">,",
        MarkFWS,
        Text " <",
        MarkFWS,
        Text "ran",
        MarkFWS,
        Text "@",
        MarkFWS,
        Text "dom",
        MarkFWS,
        Text ">"
    ]}
}