use proptest::prelude::*;

use pipeview_core::frame::Framer;
use pipeview_core::frame::cobs::{CobsFramer, cobs_decode, cobs_encode};
use pipeview_core::frame::length::{LengthConfig, LengthPrefixedFramer};
use pipeview_core::protocol::Endian;
use pipeview_core::protocol::ProtocolDecoder;
use pipeview_core::protocol::hex::{HexConfig, HexDecoder};
use pipeview_core::protocol::plot::{PlotConfig, PlotDecoder, SampleType};
use pipeview_core::protocol::text::{TextDecoder, TextEncoding};

proptest! {
    #![proptest_config(ProptestConfig::with_cases(256))]

    // ── COBS ─────────────────────────────────────────────────────────

    #[test]
    fn cobs_roundtrip_any_payload(payload in prop::collection::vec(any::<u8>(), 0..512)) {
        let encoded = cobs_encode(&payload);
        let decoded = cobs_decode(&encoded).unwrap();
        prop_assert_eq!(&decoded, &payload);

        let mut framer = CobsFramer::new(1024 * 1024);
        let mut wire = encoded;
        wire.push(0x00);
        let frames = framer.feed(&wire);
        prop_assert_eq!(frames.len(), 1);
        prop_assert_eq!(&frames[0], &payload);
    }

    // ── Length-prefixed ──────────────────────────────────────────────

    #[test]
    fn length_roundtrip_any_payload(
        len_bytes in prop_oneof![Just(1usize), Just(2usize), Just(4usize)],
        little_endian in any::<bool>(),
        includes_self in any::<bool>(),
        payload in prop::collection::vec(any::<u8>(), 0..200)
    ) {
        let endian = if little_endian { Endian::Little } else { Endian::Big };
        let raw_len = if includes_self {
            payload.len() + len_bytes
        } else {
            payload.len()
        };

        let mut wire = Vec::with_capacity(len_bytes + payload.len());
        match (len_bytes, endian) {
            (1, _) => wire.push(raw_len as u8),
            (2, Endian::Big) => wire.extend_from_slice(&(raw_len as u16).to_be_bytes()),
            (2, Endian::Little) => wire.extend_from_slice(&(raw_len as u16).to_le_bytes()),
            (4, Endian::Big) => wire.extend_from_slice(&(raw_len as u32).to_be_bytes()),
            (4, Endian::Little) => wire.extend_from_slice(&(raw_len as u32).to_le_bytes()),
            _ => unreachable!(),
        }
        wire.extend_from_slice(&payload);

        let config = LengthConfig {
            len_bytes,
            endian,
            length_includes_self: includes_self,
            max_payload: 1024 * 1024,
        };
        let mut framer = LengthPrefixedFramer::new(config);
        let frames = framer.feed(&wire);
        prop_assert_eq!(frames.len(), 1);
        prop_assert_eq!(&frames[0], &payload);
    }

    // ── Protocol decoders never panic on arbitrary bytes ─────────────

    #[test]
    fn plot_decode_arbitrary_bytes_never_panics(bytes in prop::collection::vec(any::<u8>(), 0..256)) {
        let decoder = PlotDecoder::new(PlotConfig {
            sample_type: SampleType::F32,
            endian: Endian::Little,
            channels: 2,
            format: pipeview_core::protocol::plot::PlotFormat::Interleaved,
        });
        let _ = decoder.decode(&bytes);
    }

    #[test]
    fn hex_decode_arbitrary_bytes_never_panics(bytes in prop::collection::vec(any::<u8>(), 0..256)) {
        let decoder = HexDecoder::new(HexConfig::default());
        let decoded = decoder.decode(&bytes);
        prop_assert!(decoded.is_some());
    }

    #[test]
    fn latin1_decode_arbitrary_bytes_never_panics(bytes in prop::collection::vec(any::<u8>(), 0..256)) {
        let decoder = TextDecoder::new(TextEncoding::Latin1);
        let decoded = decoder.decode(&bytes);
        prop_assert!(decoded.is_some());
    }
}