import json
import tempfile
import unittest
from pathlib import Path

from h8536.serial_pseudocode import (
    SerialPseudocodeOptions,
    generate_serial_pseudocode,
    write_serial_pseudocode,
)


def candidate_payload() -> dict:
    return {
        "instructions": [],
        "sci_protocol": {
            "manual_references": [
                "Manual/0900766b802125d0.md:15794 RDR receive data register",
                "Manual/0900766b802125d0.md:15823 TDR transmit data register",
            ],
        },
        "board_profile": {
            "summary": "Board trace ties the H8/536 SCI1 pins to a MAX202 RS232 transceiver.",
            "manual_references": [
                "Manual/0900766b802125d0.md:2417 FP-80 H8/536 pin 66 is P95/TXD",
            ],
            "traces": [
                {
                    "signal": "TXD",
                    "h8_pin": 66,
                    "h8_pin_name": "P95/TXD",
                    "max202_pin": 11,
                    "evidence": "MAX202 pin 11 traces to H8 pin 66",
                },
                {
                    "signal": "RXD",
                    "h8_pin": 67,
                    "h8_pin_name": "P96/RXD",
                    "max202_pin": 12,
                    "evidence": "MAX202 pin 12 traces to H8 pin 67",
                },
            ],
        },
        "serial_reconstruction": {
            "candidates": [
                {
                    "kind": "candidate_sci1_tx_frame",
                    "channel": "SCI1",
                    "frame_length": 6,
                    "buffer_start": 0xF858,
                    "buffer_start_hex": "H'F858",
                    "buffer_end": 0xF85D,
                    "buffer_end_hex": "H'F85D",
                    "checksum_address": 0xF85D,
                    "tx_index_address": 0xF9C2,
                    "tdr_address": 0xFEDB,
                    "checksum_seed": 0x5A,
                    "checksum_formula": "checksum = 0x5A ^ byte0 ^ byte1 ^ byte2 ^ byte3 ^ byte4",
                    "confidence": "high",
                    "confidence_score": 0.95,
                    "confidence_reason": "all required independent evidence groups were observed",
                    "comment": "candidate/evidence-supported SCI1 6-byte TX frame hypothesis",
                    "evidence_addresses_hex": {
                        "tx_checksum_seed": ["H'BA4E"],
                        "xor_checksum_chain": ["H'BA50", "H'BA54"],
                    },
                },
                {
                    "kind": "candidate_sci1_rx_frame",
                    "channel": "SCI1",
                    "frame_length": 6,
                    "capture_buffer_start": 0xF868,
                    "capture_buffer_start_hex": "H'F868",
                    "capture_buffer_end": 0xF86D,
                    "capture_buffer_end_hex": "H'F86D",
                    "validation_buffer_start": 0xF860,
                    "validation_buffer_end": 0xF865,
                    "checksum_address": 0xF865,
                    "rx_index_address": 0xF9C3,
                    "rdr_address": 0xFEDD,
                    "interbyte_timeout_address": 0xF9C1,
                    "complete_timer_address": 0xF9C5,
                    "checksum_seed": 0x5A,
                    "checksum_formula": "checksum = 0x5A ^ byte0 ^ byte1 ^ byte2 ^ byte3 ^ byte4",
                    "confidence": "high",
                    "confidence_score": 0.9,
                    "confidence_reason": "RX count, copy, and checksum-validation evidence were observed",
                    "caveat": "candidate frame means six consecutive bytes, not a proven delimited packet",
                    "comment": "candidate/evidence-supported SCI1 6-byte RX frame hypothesis",
                    "evidence_addresses_hex": {
                        "rx_rdr_read": ["H'BB6D"],
                        "rx_xor_checksum_validation": ["H'BBD6", "H'BBEC"],
                    },
                },
            ],
        },
    }


class SerialPseudocodeTest(unittest.TestCase):
    def test_generates_focused_tx_and_rx_candidate_paths(self):
        text = generate_serial_pseudocode(candidate_payload(), source_name="rom.json")

        self.assertIn("focused SCI RX/TX pseudocode from rom.json", text)
        self.assertIn("SCI1 TX 6-byte frame at H'F858-H'F85D", text)
        self.assertIn("SCI1 RX 6-byte frame captured at H'F868-H'F86D", text)
        self.assertIn("MAX202 pin 11 traces to H8 pin 66", text)
        self.assertIn("Manual/0900766b802125d0.md:15823 TDR transmit data register", text)
        self.assertIn("#define TX_FRAME(n) MEM8[(u16)(0xF858u + (n))]", text)
        self.assertIn("#define RX_CAPTURE(n) MEM8[(u16)(0xF868u + (n))]", text)
        self.assertIn("checksum ^= TX_FRAME(4);", text)
        self.assertIn("TX_FRAME(5) = sci1_tx_candidate_checksum();", text)
        self.assertIn("SCI1_TDR = TX_FRAME(0);", text)
        self.assertIn("void sci1_txi_candidate_isr(void)", text)
        self.assertIn("SCI1_SSR &= (u8)~SCI_SSR_RDRF;\n    byte = SCI1_RDR;", text)
        self.assertIn("RX_CAPTURE(RX_INDEX) = byte;", text)
        self.assertIn("return sci1_process_rx_candidate_frame();", text)
        self.assertIn("rx_xor_checksum_validation: H'BBD6, H'BBEC", text)

    def test_tx_only_option_omits_rx_functions(self):
        text = generate_serial_pseudocode(
            candidate_payload(),
            options=SerialPseudocodeOptions(include_rx=False),
        )

        self.assertIn("void sci1_tx_start_candidate_frame(void)", text)
        self.assertNotIn("sci1_rx_byte_received_candidate_isr", text)

    def test_write_serial_pseudocode_writes_output_file(self):
        with tempfile.TemporaryDirectory() as tmp:
            input_path = Path(tmp) / "rom.json"
            output_path = Path(tmp) / "serial.c"
            input_path.write_text(
                json.dumps(candidate_payload()),
                encoding="utf-8",
            )

            write_serial_pseudocode(input_path, output_path, SerialPseudocodeOptions())

            self.assertIn("sci1_process_rx_candidate_frame", output_path.read_text(encoding="utf-8"))


if __name__ == "__main__":
    unittest.main()