mod boolean;
mod from;
mod list;
mod primitive;
mod utf8;

use crate::{
    prelude::*,
    utils::{get_iter_capacity, NoNull},
};
use arrow::{array::*, bitmap::Bitmap};
use std::borrow::Cow;
use std::iter::FromIterator;
use std::marker::PhantomData;
use std::sync::Arc;
pub use {boolean::*, list::*, primitive::*, utf8::*};

// N: the value type; T: the sentinel type
pub trait ChunkedBuilder<N, T> {
    fn append_value(&mut self, val: N);
    fn append_null(&mut self);
    fn append_option(&mut self, opt_val: Option<N>) {
        match opt_val {
            Some(v) => self.append_value(v),
            None => self.append_null(),
        }
    }
    fn finish(self) -> ChunkedArray<T>;

    fn shrink_to_fit(&mut self);
}

// Used in polars/src/chunked_array/apply.rs:24 to collect from aligned vecs and null bitmaps
impl<T> FromIterator<(AlignedVec<T::Native>, Option<Bitmap>)> for ChunkedArray<T>
where
    T: PolarsNumericType,
{
    fn from_iter<I: IntoIterator<Item = (AlignedVec<T::Native>, Option<Bitmap>)>>(iter: I) -> Self {
        let mut chunks = vec![];

        for (values, opt_buffer) in iter {
            chunks.push(to_array::<T>(values, opt_buffer))
        }
        ChunkedArray::new_from_chunks("from_iter", chunks)
    }
}

pub trait NewChunkedArray<T, N> {
    fn new_from_slice(name: &str, v: &[N]) -> Self;
    fn new_from_opt_slice(name: &str, opt_v: &[Option<N>]) -> Self;

    /// Create a new ChunkedArray from an iterator.
    fn new_from_opt_iter(name: &str, it: impl Iterator<Item = Option<N>>) -> Self;

    /// Create a new ChunkedArray from an iterator.
    fn new_from_iter(name: &str, it: impl Iterator<Item = N>) -> Self;
}

impl<T> NewChunkedArray<T, T::Native> for ChunkedArray<T>
where
    T: PolarsNumericType,
{
    fn new_from_slice(name: &str, v: &[T::Native]) -> Self {
        let arr = PrimitiveArray::<T::Native>::from_slice(v).to(T::get_dtype().to_arrow());
        ChunkedArray::new_from_chunks(name, vec![Arc::new(arr)])
    }

    fn new_from_opt_slice(name: &str, opt_v: &[Option<T::Native>]) -> Self {
        Self::new_from_opt_iter(name, opt_v.iter().copied())
    }

    fn new_from_opt_iter(
        name: &str,
        it: impl Iterator<Item = Option<T::Native>>,
    ) -> ChunkedArray<T> {
        let mut builder = PrimitiveChunkedBuilder::new(name, get_iter_capacity(&it));
        it.for_each(|opt| builder.append_option(opt));
        builder.finish()
    }

    /// Create a new ChunkedArray from an iterator.
    fn new_from_iter(name: &str, it: impl Iterator<Item = T::Native>) -> ChunkedArray<T> {
        let ca: NoNull<ChunkedArray<_>> = it.collect();
        let mut ca = ca.into_inner();
        ca.rename(name);
        ca
    }
}

impl NewChunkedArray<BooleanType, bool> for BooleanChunked {
    fn new_from_slice(name: &str, v: &[bool]) -> Self {
        Self::new_from_iter(name, v.iter().copied())
    }

    fn new_from_opt_slice(name: &str, opt_v: &[Option<bool>]) -> Self {
        Self::new_from_opt_iter(name, opt_v.iter().copied())
    }

    fn new_from_opt_iter(
        name: &str,
        it: impl Iterator<Item = Option<bool>>,
    ) -> ChunkedArray<BooleanType> {
        let mut builder = BooleanChunkedBuilder::new(name, get_iter_capacity(&it));
        it.for_each(|opt| builder.append_option(opt));
        builder.finish()
    }

    /// Create a new ChunkedArray from an iterator.
    fn new_from_iter(name: &str, it: impl Iterator<Item = bool>) -> ChunkedArray<BooleanType> {
        let mut ca: ChunkedArray<_> = it.collect();
        ca.rename(name);
        ca
    }
}

impl<S> NewChunkedArray<Utf8Type, S> for Utf8Chunked
where
    S: AsRef<str>,
{
    fn new_from_slice(name: &str, v: &[S]) -> Self {
        let values_size = v.iter().fold(0, |acc, s| acc + s.as_ref().len());

        let mut builder = MutableUtf8Array::<i64>::with_capacities(v.len(), values_size);
        v.iter().for_each(|val| {
            builder.push(Some(val.as_ref()));
        });

        let field = Arc::new(Field::new(name, DataType::Utf8));

        ChunkedArray {
            field,
            chunks: vec![builder.into_arc()],
            phantom: PhantomData,
            categorical_map: None,
            ..Default::default()
        }
    }

    fn new_from_opt_slice(name: &str, opt_v: &[Option<S>]) -> Self {
        let values_size = opt_v.iter().fold(0, |acc, s| match s {
            Some(s) => acc + s.as_ref().len(),
            None => acc,
        });
        let mut builder = Utf8ChunkedBuilder::new(name, opt_v.len(), values_size);

        opt_v.iter().for_each(|opt| match opt {
            Some(v) => builder.append_value(v.as_ref()),
            None => builder.append_null(),
        });
        builder.finish()
    }

    fn new_from_opt_iter(name: &str, it: impl Iterator<Item = Option<S>>) -> Self {
        let cap = get_iter_capacity(&it);
        let mut builder = Utf8ChunkedBuilder::new(name, cap, cap * 5);
        it.for_each(|opt| builder.append_option(opt));
        builder.finish()
    }

    /// Create a new ChunkedArray from an iterator.
    fn new_from_iter(name: &str, it: impl Iterator<Item = S>) -> Self {
        let cap = get_iter_capacity(&it);
        let mut builder = Utf8ChunkedBuilder::new(name, cap, cap * 5);
        it.for_each(|v| builder.append_value(v));
        builder.finish()
    }
}

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

    #[test]
    fn test_primitive_builder() {
        let mut builder = PrimitiveChunkedBuilder::<UInt32Type>::new("foo", 6);
        let values = &[Some(1), None, Some(2), Some(3), None, Some(4)];
        for val in values {
            builder.append_option(*val);
        }
        let ca = builder.finish();
        assert_eq!(Vec::from(&ca), values);
    }

    #[test]
    fn test_list_builder() {
        let mut builder = ListPrimitiveChunkedBuilder::<Int32Type>::new("a", 10, 5);

        // create a series containing two chunks
        let mut s1 = Int32Chunked::new_from_slice("a", &[1, 2, 3]).into_series();
        let s2 = Int32Chunked::new_from_slice("b", &[4, 5, 6]).into_series();
        s1.append(&s2).unwrap();

        builder.append_series(&s1);
        builder.append_series(&s2);
        let ls = builder.finish();
        if let AnyValue::List(s) = ls.get_any_value(0) {
            // many chunks are aggregated to one in the ListArray
            assert_eq!(s.len(), 6)
        } else {
            panic!()
        }
        if let AnyValue::List(s) = ls.get_any_value(1) {
            assert_eq!(s.len(), 3)
        } else {
            panic!()
        }
        // test list collect
        let out = [&s1, &s2].iter().copied().collect::<ListChunked>();
        assert_eq!(out.get(0).unwrap().len(), 6);
        assert_eq!(out.get(1).unwrap().len(), 3);

        let mut builder = ListPrimitiveChunkedBuilder::<Int32Type>::new("a", 10, 5);
        builder.append_series(&s1);
        builder.append_null();

        let out = builder.finish();
        let out = out.explode().unwrap();
        assert_eq!(out.len(), 7);
        assert_eq!(out.get(6), AnyValue::Null);
    }

    #[test]
    fn test_list_str_builder() {
        let mut builder = ListUtf8ChunkedBuilder::new("a", 10, 10);
        builder.append_series(&Series::new("", &["foo", "bar"]));
        let ca = builder.finish();
        dbg!(ca);
    }
}