Documentation
// Copyright 2019 YechaoLi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#[macro_use]
extern crate lazy_static;

pub mod email;
pub mod error;
pub mod ip;
pub mod length;
pub mod r#match;
pub mod url;

use std::{borrow::Cow, collections::BTreeMap};

pub trait Prove {
    fn prove(&self) -> Result<(), error::ValidationError>;
}

impl<T> Prove for Option<T>
where
    T: Prove,
{
    fn prove(&self) -> Result<(), error::ValidationError> {
        match self {
            Some(v) => v.prove(),
            None => Ok(()),
        }
    }
}

impl<T> Prove for Vec<T>
where
    T: Prove,
{
    fn prove(&self) -> Result<(), error::ValidationError> {
        let mut errors = BTreeMap::new();

        for (index, item) in self.iter().enumerate() {
            if let Err(error) = item.prove() {
                errors.insert(index as u64, error);
            }
        }

        if errors.is_empty() {
            Ok(())
        } else {
            Err(error::ValidationError::List(errors))
        }
    }
}

macro_rules! tuple_impls {
    ($(
        ($(($idx:tt)),+)
    )+) => {
        tuple_impls! {
            $(
                ($((T, $idx)),+)
            )+
        }
    };
    ($(
        ($(($T:ident, $idx:tt)),+)
    )+) => {
        $(
            impl<T> Prove for ($($T),+) where T: Prove {
                fn prove(&self) -> Result<(), error::ValidationError> {
                    let mut errors = std::collections::BTreeMap::new();

                    $(
                        if let Err(error) = self.$idx.prove() {
                            errors.insert($idx, error);
                        }
                    )+

                    if errors.is_empty() {
                        Ok(())
                    } else {
                        Err(error::ValidationError::List(errors))
                    }
                }
            }
        )+
    };
}

tuple_impls! {
    ((0), (1))
    ((0), (1), (2))
    ((0), (1), (2), (3))
    ((0), (1), (2), (3), (4))
    ((0), (1), (2), (3), (4), (5))
    ((0), (1), (2), (3), (4), (5), (6))
    ((0), (1), (2), (3), (4), (5), (6), (7))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8), (9))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8), (9), (10))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11))
    ((0), (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12))
}

pub trait AsValidateStr<'a> {
    fn as_validate_str(&'a self) -> Option<Cow<'a, str>>;
}

impl<'a> AsValidateStr<'a> for String {
    fn as_validate_str(&'a self) -> Option<Cow<'a, str>> {
        Some(Cow::Borrowed(self))
    }
}

impl<'a> AsValidateStr<'a> for &'a String {
    fn as_validate_str(&'a self) -> Option<Cow<'a, str>> {
        Some(Cow::Borrowed(self))
    }
}

impl<'a> AsValidateStr<'a> for &'a str {
    fn as_validate_str(&'a self) -> Option<Cow<'a, str>> {
        Some(Cow::Borrowed(self))
    }
}

impl<'a, T> AsValidateStr<'a> for Option<T>
where
    T: AsValidateStr<'a>,
{
    fn as_validate_str(&'a self) -> Option<Cow<'a, str>> {
        match self {
            None => None,
            Some(v) => v.as_validate_str(),
        }
    }
}