use rand::{thread_rng, RngCore};
use twenty_first::shared_math::b_field_element::BFieldElement;

use crate::{
    get_init_tvm_stack,
    snippet::{DataType, Snippet},
    ExecutionState,
};

#[derive(Clone, Debug)]
pub struct OrU32;

impl Snippet for OrU32 {
    fn entrypoint(&self) -> String {
        "tasm_arithmetic_u32_or_u32".to_string()
    }

    fn inputs(&self) -> Vec<String> {
        vec!["rhs".to_string(), "lhs".to_string()]
    }

    fn outputs(&self) -> Vec<String> {
        vec!["lhs | rhs".to_string()]
    }

    fn input_types(&self) -> Vec<crate::snippet::DataType> {
        vec![DataType::U32, DataType::U32]
    }

    fn output_types(&self) -> Vec<crate::snippet::DataType> {
        vec![DataType::U32]
    }

    fn stack_diff(&self) -> isize {
        -1
    }

    fn function_code(&self, _library: &mut crate::snippet_state::SnippetState) -> String {
        let entrypoint = self.entrypoint();
        format!(
            "
                // BEFORE: _ rhs lhs
                // AFTER: _ (lhs | rhs)
                {entrypoint}:
                    dup 1
                    dup 1
                    xor
                    // _ rhs lhs (rhs ^ lhs)

                    swap 2
                    and
                    // _ (rhs ^ lhs) (lhs & rhs)

                    add

                    return
                    "
        )
    }

    fn crash_conditions(&self) -> Vec<String> {
        vec!["Inputs are not u32".to_owned()]
    }

    fn gen_input_states(&self) -> Vec<crate::ExecutionState> {
        let mut ret: Vec<ExecutionState> = vec![];
        for _ in 0..100 {
            let mut stack = get_init_tvm_stack();
            let lhs = thread_rng().next_u32();
            let rhs = thread_rng().next_u32();
            let lhs = BFieldElement::new(lhs as u64);
            let rhs = BFieldElement::new(rhs as u64);
            stack.push(rhs);
            stack.push(lhs);
            ret.push(ExecutionState::with_stack(stack));
        }

        ret
    }

    fn rust_shadowing(
        &self,
        stack: &mut Vec<twenty_first::shared_math::b_field_element::BFieldElement>,
        _std_in: Vec<twenty_first::shared_math::b_field_element::BFieldElement>,
        _secret_in: Vec<twenty_first::shared_math::b_field_element::BFieldElement>,
        _memory: &mut std::collections::HashMap<
            twenty_first::shared_math::b_field_element::BFieldElement,
            twenty_first::shared_math::b_field_element::BFieldElement,
        >,
    ) {
        let lhs: u32 = stack.pop().unwrap().try_into().unwrap();
        let rhs: u32 = stack.pop().unwrap().try_into().unwrap();

        let or = lhs | rhs;
        stack.push(BFieldElement::new(or as u64));
    }

    fn common_case_input_state(&self) -> ExecutionState {
        ExecutionState::with_stack(
            vec![
                get_init_tvm_stack(),
                vec![BFieldElement::new(1 << 15), BFieldElement::new(1 << 16)],
            ]
            .concat(),
        )
    }

    fn worst_case_input_state(&self) -> ExecutionState {
        ExecutionState::with_stack(
            vec![
                get_init_tvm_stack(),
                vec![
                    BFieldElement::new((1 << 32) - 1),
                    BFieldElement::new((1 << 32) - 1),
                ],
            ]
            .concat(),
        )
    }
}

#[cfg(test)]
mod tests {
    use std::collections::HashMap;

    use crate::test_helpers::{
        test_rust_equivalence_given_input_values, test_rust_equivalence_multiple,
    };

    use super::*;

    #[test]
    fn snippet_test() {
        test_rust_equivalence_multiple(&OrU32, true);
    }

    #[test]
    fn or_simple_test() {
        prop_safe_or(10, 1, Some(11));
        prop_safe_or(256, 30, Some(286));
        prop_safe_or(123, 0, Some(123));
        prop_safe_or(0, 123, Some(123));
        prop_safe_or(1 << 31, 1 << 30, Some((1 << 30) + (1 << 31)));
        prop_safe_or(0, 0, Some(0));
        prop_safe_or(14, 0, Some(14));
        prop_safe_or(u32::MAX, 0, Some(u32::MAX));
        prop_safe_or(0, u32::MAX, Some(u32::MAX));
        prop_safe_or(u32::MAX, u32::MAX, Some(u32::MAX));
    }

    fn prop_safe_or(lhs: u32, rhs: u32, _expected: Option<u32>) {
        let mut init_stack = get_init_tvm_stack();
        init_stack.push(BFieldElement::new(rhs as u64));
        init_stack.push(BFieldElement::new(lhs as u64));

        let expected = lhs | rhs;
        let expected = vec![
            get_init_tvm_stack(),
            vec![BFieldElement::new(expected as u64)],
        ]
        .concat();

        test_rust_equivalence_given_input_values(
            &OrU32,
            &init_stack,
            &[],
            &[],
            &mut HashMap::default(),
            0,
            Some(&expected),
        );
    }
}

#[cfg(test)]
mod benches {
    use super::*;
    use crate::snippet_bencher::bench_and_write;

    #[test]
    fn u32_or_benchmark() {
        bench_and_write(OrU32);
    }
}