// Copyright 2025 Don MacAskill. Licensed under MIT or Apache-2.0.

//! Utility to generate pre-computed 16-lane lookup tables for all CRC algorithms.

//!

//! This generates Rust source code that can be used to create the `src/tables.rs` module.

//! Run with: `cargo run --bin generate_tables > src/tables.rs`

use crc_fast::arch::software::{generate_table_u16, generate_table_u32, generate_table_u64};

fn main() {

    println!("// Copyright 2025 Don MacAskill. Licensed under MIT or Apache-2.0.");

    println!();

    println!("//! Pre-generated 16-lane lookup tables for CRC calculations.");

    println!("//!");

    println!("//! This file is auto-generated by `cargo run --bin generate_tables`.");

    println!("//! Do not edit manually.");

    println!();

    println!("#![allow(dead_code)]");

    println!();

    generate_crc16_tables();

    generate_crc32_tables();

    generate_crc64_tables();

}

fn generate_crc16_tables() {

    println!("pub mod crc16 {{");

    println!("    //! CRC-16 lookup tables");

    println!();

    // CRC-16 algorithms with their parameters: (name, poly, reflect)

    let algorithms: &[(&str, u16, bool)] = &[

        ("ARC", 0x8005, true),

        ("CDMA2000", 0xc867, false),

        ("CMS", 0x8005, false),

        ("DDS_110", 0x8005, false),

        ("DECT_R", 0x0589, false),

        ("DECT_X", 0x0589, false),

        ("DNP", 0x3d65, true),

        ("EN_13757", 0x3d65, false),

        ("GENIBUS", 0x1021, false),

        ("GSM", 0x1021, false),

        ("IBM_3740", 0x1021, false),

        ("IBM_SDLC", 0x1021, true),

        ("ISO_IEC_14443_3_A", 0x1021, true),

        ("KERMIT", 0x1021, true),

        ("LJ1200", 0x6f63, false),

        ("M17", 0x5935, false),

        ("MAXIM_DOW", 0x8005, true),

        ("MCRF4XX", 0x1021, true),

        ("MODBUS", 0x8005, true),

        ("NRSC_5", 0x080b, true),

        ("OPENSAFETY_A", 0x5935, false),

        ("OPENSAFETY_B", 0x755b, false),

        ("PROFIBUS", 0x1dcf, false),

        ("RIELLO", 0x1021, true),

        ("SPI_FUJITSU", 0x1021, false),

        ("T10_DIF", 0x8bb7, false),

        ("TELEDISK", 0xa097, false),

        ("TMS37157", 0x1021, true),

        ("UMTS", 0x8005, false),

        ("USB", 0x8005, true),

        ("XMODEM", 0x1021, false),

    ];

    for (name, poly, reflect) in algorithms {

        print_table_u16(name, 16, *poly, *reflect);

    }

    println!("}}");

    println!();

}

fn generate_crc32_tables() {

    println!("pub mod crc32 {{");

    println!("    //! CRC-32 lookup tables");

    println!();

    // CRC-32 algorithms with their parameters: (name, poly, reflect)

    let algorithms: &[(&str, u32, bool)] = &[

        ("AIXM", 0x814141ab, false),

        ("AUTOSAR", 0xf4acfb13, true),

        ("BASE91_D", 0xa833982b, true),

        ("BZIP2", 0x04c11db7, false),

        ("CD_ROM_EDC", 0x8001801b, true),

        ("CKSUM", 0x04c11db7, false),

        ("ISCSI", 0x1edc6f41, true),

        ("ISO_HDLC", 0x04c11db7, true),

        ("JAMCRC", 0x04c11db7, true),

        ("MEF", 0x741b8cd7, true),

        ("MPEG_2", 0x04c11db7, false),

        ("XFER", 0x000000af, false),

    ];

    for (name, poly, reflect) in algorithms {

        print_table_u32(name, 32, *poly, *reflect);

    }

    println!("}}");

    println!();

}

fn generate_crc64_tables() {

    println!("pub mod crc64 {{");

    println!("    //! CRC-64 lookup tables");

    println!();

    // CRC-64 algorithms with their parameters: (name, poly, reflect)

    let algorithms: &[(&str, u64, bool)] = &[

        ("ECMA_182", 0x42f0e1eba9ea3693, false),

        ("GO_ISO", 0x000000000000001b, true),

        ("MS", 0x259c84cba6426349, true),

        ("NVME", 0xad93d23594c93659, true),

        ("REDIS", 0xad93d23594c935a9, true),

        ("WE", 0x42f0e1eba9ea3693, false),

        ("XZ", 0x42f0e1eba9ea3693, true),

    ];

    for (name, poly, reflect) in algorithms {

        print_table_u64(name, 64, *poly, *reflect);

    }

    println!("}}");

}

fn print_table_u16(name: &str, width: u8, poly: u16, reflect: bool) {

    let table = generate_table_u16(width, poly, reflect);

    println!("    pub static CRC16_{}_TABLE: [[u16; 256]; 16] = [", name);

    for lane in &table {

        println!("        [");

        for chunk in lane.chunks(8) {

            print!("            ");

            for (i, val) in chunk.iter().enumerate() {

                print!("0x{:04x}", val);

                if i < chunk.len() - 1 {

                    print!(", ");

                }

            }

            println!(",");

        }

        println!("        ],");

    }

    println!("    ];");

    println!();

}

fn print_table_u32(name: &str, width: u8, poly: u32, reflect: bool) {

    let table = generate_table_u32(width, poly, reflect);

    println!("    pub static CRC32_{}_TABLE: [[u32; 256]; 16] = [", name);

    for lane in &table {

        println!("        [");

        for chunk in lane.chunks(4) {

            print!("            ");

            for (i, val) in chunk.iter().enumerate() {

                print!("0x{:08x}", val);

                if i < chunk.len() - 1 {

                    print!(", ");

                }

            }

            println!(",");

        }

        println!("        ],");

    }

    println!("    ];");

    println!();

}

fn print_table_u64(name: &str, width: u8, poly: u64, reflect: bool) {

    let table = generate_table_u64(width, poly, reflect);

    println!("    pub static CRC64_{}_TABLE: [[u64; 256]; 16] = [", name);

    for lane in &table {

        println!("        [");

        for chunk in lane.chunks(2) {

            print!("            ");

            for (i, val) in chunk.iter().enumerate() {

                print!("0x{:016x}", val);

                if i < chunk.len() - 1 {

                    print!(", ");

                }

            }

            println!(",");

        }

        println!("        ],");

    }

    println!("    ];");

    println!();

}