import re
import sys
import cantools

def parse_dbc_file(file_path):
    signals = []
    current_message = None
    try:
        with open(file_path, 'r', encoding='cp1252') as f:
            lines = f.readlines()
        print(f"[INFO] Read {len(lines)} lines from DBC file.")

        start_parsing = False
        for line in lines:
            line = line.strip()
            if not line:
                continue

            if not start_parsing:
                if line.startswith("BO_"):
                    start_parsing = True
                else:
                    continue

            if line.startswith("BO_"):
                if current_message and current_message["signals"]:
                    signals.append(current_message)
                    print(f"[INFO] Added message: {current_message['name']} with {len(current_message['signals'])} signals.")

                parts = line.split()
                if len(parts) < 5:
                    print(f"[WARNING] Skipping malformed BO_ line: {line}")
                    continue

                current_message = {
                    "id": parts[1],
                    "name": parts[2].replace(":", ""),
                    "dlc": parts[3],
                    "transmitter": parts[4],
                    "signals": []
                }
                print(f"[INFO] Found message: {current_message['name']}")

            elif line.startswith("SG_") and current_message:
                try:
                    parts = line.split(":")
                    if len(parts) < 2:
                        print(f"[WARNING] Skipping malformed SG_ line: {line}")
                        continue

                    signal_name = parts[0].split()[1].strip()
                    bit_info = parts[1].split()[0]
                    receiver = parts[1].split()[-1]

                    if current_message["transmitter"] != "VCU":
                        continue

                    byte_offset, rest = bit_info.split("|")
                    bit_offset = int(rest.split("@")[0])
                    size = int(re.search(r'\d+', rest.split("@")[0]).group())
                    factor_offset_match = re.search(r'\(([^)]+)\)', line)
                    if not factor_offset_match:
                        print(f"[WARNING] Skipping signal with missing factor/offset: {line}")
                        continue

                    factor_offset = factor_offset_match.group(1).split(",")
                    factor = float(factor_offset[0])
                    offset = float(factor_offset[1])

                    current_message["signals"].append({
                        "name": signal_name,
                        "byte_offset": int(byte_offset) // 8,
                        "bit_offset": bit_offset,
                        "size": size,
                        "factor": factor,
                        "offset": offset,
                        "signed": '-' in rest.split("@")[1]
                    })
                    print(f"[INFO] Added signal: {signal_name}")
                except (ValueError, IndexError, AttributeError) as e:
                    print(f"[ERROR] Error parsing signal: {line}, {e}")
                    continue

        if current_message and current_message["signals"]:
            signals.append(current_message)
            print(f"[INFO] Added last message: {current_message['name']} with {len(current_message['signals'])} signals.")

    except Exception as e:
        print(f"[ERROR] Error while parsing DBC file: {e}")
        return []

    print(f"[INFO] Parsed {len(signals)} messages.")
    return signals


def generate_tx_structs(signals, output_file):
    if not signals:
        print("[WARNING] No signals to generate TX structs for.")
        return

    with open(output_file, 'w') as f:
        f.write("#ifndef GENERATED_TX_STRUCTS_H\n")
        f.write("#define GENERATED_TX_STRUCTS_H\n\n")
        f.write("#include <stdint.h>\n\n")

        for message in signals:
            hex_id = f"0x{int(message['id']):X}"
            f.write(f"typedef struct\n{{\n")
            for signal in message["signals"]:
                if signal["size"] <= 32:
                    f.write(f"    uint32_t {signal['name']} : {signal['size']};\n")
                else:
                    f.write(f"    float {signal['name']};\n")
            f.write(f"}} CH0_{message['name']}_{hex_id};\n\n")
        f.write("#endif // GENERATED_TX_STRUCTS_H\n")
    print(f"[INFO] TX structs written to {output_file}")


def generate_tx_globals(signals, output_file, header_file):
    if not signals:
        print("[WARNING] No signals to generate TX globals for.")
        return

    with open(output_file, 'w') as f:
        for message in signals:
            for signal in message["signals"]:
                if signal["size"] > 32:
                    f.write(f"float GV_{signal['name']} = 0.0f;\n")
                else:
                    f.write(f"uint32_t GV_{signal['name']} = 0;\n")

    with open(header_file, 'w') as f:
        f.write("#ifndef GENERATED_TX_GLOBALS_H\n")
        f.write("#define GENERATED_TX_GLOBALS_H\n\n")
        f.write("#include <stdint.h>\n\n")
        for message in signals:
            for signal in message["signals"]:
                if signal["size"] > 32:
                    f.write(f"extern float GV_{signal['name']};\n")
                else:
                    f.write(f"extern uint32_t GV_{signal['name']};\n")
        f.write("\n#endif // GENERATED_TX_GLOBALS_H\n")
    print(f"[INFO] TX globals written to {output_file} and {header_file}")


def generate_tx_functions(signals, output_file):
    if not signals:
        print("[WARNING] No signals to generate TX functions for.")
        return

    with open(output_file, 'w') as f:
        for message in signals:
            hex_id = f"0x{int(message['id']):X}"
            function_name = f"void Output_Data_Set_{message['name']}_CH0_{hex_id}(void)"
            f.write(f"{function_name}\n{{\n")
            for signal in message["signals"]:
                factor_str = f"/ {signal['factor']}" if signal["factor"] != 1.0 else ""
                offset_str = f"- {signal['offset']}" if signal["offset"] != 0.0 else ""
                mask = f"_{signal['size']}bit"
                f.write(
                    f"    ECU3.TX.CH0_{message['name']}_{hex_id}.{signal['name']} = "
                    f"(int)((GV_{signal['name']} {offset_str}) {factor_str}) & {mask};\n"
                )
            f.write("}\n\n")
    print(f"[INFO] TX functions written to {output_file}")

def generate_tx_initialization(signals, output_file):
    if not signals:
        print("[WARNING] No TX signals found for initialization generation.")
        return

    with open(output_file, 'w') as f:
        f.write("void Initialize_TX_Signals(void)\n{\n")
        for message in signals:
            hex_id = f"0x{int(message['id']):X}"
            f.write(f"    // {message['name']} ({hex_id})\n")
            for signal in message["signals"]:
                f.write(f"    ECU3.TX.CH0_{message['name']}_{hex_id}.{signal['name']} = 0;\n")
            f.write("\n")
        f.write("}\n")
    print(f"[INFO] TX initialization function written to {output_file}")

def parse_dbc_for_tx_messages(file_path):
    tx_messages = []
    try:
        with open(file_path, 'r', encoding='cp1252') as f:
            lines = f.readlines()
        print(f"[INFO] Read {len(lines)} lines from DBC file.")

        for line in lines:
            line = line.strip()
            if not line:
                continue

            if line.startswith("BO_"):
                parts = line.split()
                if len(parts) < 5:
                    print(f"[WARNING] Skipping malformed BO_ line: {line}")
                    continue

                message_id = int(parts[1])  # ID for sorting
                message_name = parts[2].replace(":", "")
                transmitter = parts[4]

                # Only include messages transmitted by VCU
                if transmitter == "VCU":
                    tx_messages.append((message_id, message_name))
                    print(f"[INFO] Found TX message: {message_name} (ID: {message_id})")

    except Exception as e:
        print(f"[ERROR] Error while parsing DBC file: {e}")

    # Sort messages by message name or ID
    tx_messages.sort(key=lambda x: x[0])  # Sort by message ID
    return [message[1] for message in tx_messages]


def generate_tx_enum(tx_messages, output_file, cycle):
    if not tx_messages:
        print("[WARNING] No TX messages found for enum generation.")
        return

    with open(output_file, 'w') as f:
        f.write("typedef enum {\n")
        for idx, message in enumerate(tx_messages):
            enum_name = f"ECU3_CH0_TX_{message}_{cycle}"
            f.write(f"    {enum_name} = {idx},\n")
        f.write("    NUMBER_OF_ECU3_CH0_TX_MESSAGE,\n")
        f.write("} ECU3_CH0_TX;\n")
    print(f"[INFO] TX enum written to {output_file}")

def generate_vcu_can_transmit_single_c_file(dbc_path, output_file):
    # Load the DBC file
    db = cantools.database.load_file(dbc_path)

    # Initialize the header of the C file
    c_file_content = """
#include "can.h"
"""

    # Iterate through all messages in the DBC file
    for message in db.messages:
        # Check if the message's sending node is "VCU"
        if "VCU" in message.senders:
            # Add the function definition for the message
            c_file_content += f"""
void Transmit_{message.name}_CH0_0x{message.frame_id:X}(void)
{{
"""

            # Iterate through signals and generate bit-packing logic
            buffer_assignments = [""] * message.length
            for signal in message.signals:
                start_byte = signal.start // 8
                start_bit = signal.start % 8
                signal_length = signal.length
                signal_name = f"ECU3.TX.CH0_{message.name}_0x{message.frame_id:X}.{signal.name}"

                # Handle 8-bit chunks
                while signal_length > 0:
                    bits_in_byte = min(8 - start_bit, signal_length)
                    shift_amount = (signal.length - signal_length)
                    shift_expr = f"({signal_name} >> shift{shift_amount}) << shift{start_bit}" if start_bit > 0 else f"({signal_name} >> shift{shift_amount})"
                    buffer_index = start_byte

                    # Add to the buffer assignments
                    if buffer_assignments[buffer_index]:
                        buffer_assignments[buffer_index] += f"\n                         | {shift_expr}"
                    else:
                        buffer_assignments[buffer_index] = f"{shift_expr}"

                    # Update pointers
                    signal_length -= bits_in_byte
                    start_byte += 1
                    start_bit = 0

            # Write buffer assignments to the function
            for i, assignment in enumerate(buffer_assignments):
                if assignment:
                    c_file_content += f"    CAN_ch[0].tx.buf[{i}] = ({assignment}) & _8bit;\n"

            # Add the send function call
            c_file_content += f"""
    can_send_config(CAN_INST_0, g_messageObjectConf_ECU3_0ch_TX[ECU3_CH0_TX_{message.name}_10ms]);
}}
"""

    # Write the generated code to a single C file
    with open(output_file, "w") as c_file:
        c_file.write(c_file_content)
    print(f"Generated C file with all VCU messages: {output_file}")


if __name__ == "__main__":
    dbc_file_path = sys.argv[1]
    output_structs_file = "C:/Users/MSI/Desktop/DB/generated_tx_structs.h"
    output_globals_file = "C:/Users/MSI/Desktop/DB/generated_tx_globals.c"
    output_globals_header = "C:/Users/MSI/Desktop/DB/generated_tx_globals.h"
    output_tx_functions_file = "C:/Users/MSI/Desktop/DB/generated_tx_functions.c"
    output_tx_initialization = "C:/Users/MSI/Desktop/DB/generated_tx_initialization.c"
    output_enum_file = "C:/Users/MSI/Desktop/DB/generated_tx_enum.h"
    cycle_time = "10ms"
    output_c_file = "C:/Users/MSI/Desktop/DB/Transmit_All_VCU_Messages.c"  # Replace with your desired output file name

    generate_vcu_can_transmit_single_c_file(dbc_file_path, output_c_file)


    signals = parse_dbc_file(dbc_file_path)
    generate_tx_structs(signals, output_structs_file)
    generate_tx_globals(signals, output_globals_file, output_globals_header)
    generate_tx_functions(signals, output_tx_functions_file)
    generate_tx_initialization(signals, output_tx_initialization)
    tx_messages = parse_dbc_for_tx_messages(dbc_file_path)
    generate_tx_enum(tx_messages, output_enum_file, cycle_time)