#!/usr/bin/env python3
"""Generate Tiny integration bindings and absolute source lists from owned maps."""

from __future__ import annotations

import argparse
import json
import re
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parents[1]
sys.path.insert(0, str(ROOT))
from scripts.rtl.generate_memory_map import generate as generate_memory_map  # noqa: E402
from scripts.rtl.generate_pin_map import generate as generate_pin_map  # noqa: E402
from scripts.setup_helpers import atomic_write  # noqa: E402

TINY = ROOT / "rtl/tiny"


def read_topology(path: Path, memory_map: Path) -> dict:
    document = json.loads(path.read_text())
    regions = {r["symbol"] for r in json.loads(memory_map.read_text())["regions"]}
    if document.get("schema_version") != 1 or document.get("dma_channels") != 4:
        raise ValueError("Tiny requires topology schema 1 and four DMA channels")
    if document.get("irq_vector_width") != 32 or document.get("external_irq_count") != 30:
        raise ValueError("Tiny requires a 32-bit IRQ vector and 30 external inputs")
    names: set[str] = set()
    bits: set[int] = set()
    for irq in document["interrupts"]:
        if irq["name"] in names or irq["core_bit"] in bits:
            raise ValueError("duplicate Tiny interrupt")
        if not 0 <= irq["core_bit"] < 32:
            raise ValueError("Tiny IRQ outside vector")
        names.add(irq["name"])
        bits.add(irq["core_bit"])
    assigned: set[str] = set()
    for target in document["apb_targets"]:
        for region in target["regions"]:
            if region not in regions or region in assigned:
                raise ValueError(f"invalid or duplicate APB region {region}")
            assigned.add(region)
    if assigned != {r for r in regions if r.startswith("APB4_")}:
        raise ValueError("Tiny topology must route every APB region")
    if len(document["apb_targets"]) != 16:
        raise ValueError("Tiny's fixed APB bridge requires sixteen targets")
    target_names = [target["name"] for target in document["apb_targets"]]
    if len(set(target_names)) != 16 or any(re.fullmatch(r"[a-z][a-z0-9_]*", name) is None
                                         for name in target_names):
        raise ValueError("Tiny APB target names must be unique identifiers")
    if sorted(item["pin"] for item in document["gpio_alt_functions"]) != list(range(32)):
        raise ValueError("Tiny GPIO map must contain all 32 pins exactly once")
    return document


def generate_bindings(document: dict, output: Path) -> None:
    comment = "// Generated by scripts/generate_tiny.py; do not edit.\n"
    irq = [comment, "always_comb begin", "  s_irq = '0;"]
    header = ["#ifndef RETROSOC_GENERATED_IRQ_METADATA_H",
              "#define RETROSOC_GENERATED_IRQ_METADATA_H", "#include <stdint.h>",
              "#define RS_SOC_IRQ_VECTOR_WIDTH UINT32_C(32)",
              "#define RS_SOC_EXTERNAL_IRQ_COUNT UINT32_C(30)",
              f"#define RS_SOC_ALLOCATED_IRQ_COUNT UINT32_C({len(document['interrupts']) - 2})"]
    for item in document["interrupts"]:
        bit, name = item["core_bit"], item["name"].upper()
        irq.append(f"  s_irq[{bit}] = {item['signal']};")
        header.append(f"#define RS_SOC_IRQ_{name} UINT32_C({bit})")
        if bit >= 2:
            header.append(f"#define RS_SOC_EXT_IRQ_{name} UINT32_C({bit - 2})")
    irq.append("end\n")
    header.append("#endif\n")
    atomic_write(output / "rtl/tiny_irq.svh", "\n".join(irq))
    atomic_write(output / "include/retrosoc/generated/irq_metadata.h", "\n".join(header))
    atomic_write(output / "include/retrosoc/generated/user_extensions.h",
                 "#ifndef RETROSOC_GENERATED_USER_EXTENSIONS_H\n"
                 "#define RETROSOC_GENERATED_USER_EXTENSIONS_H\n"
                 "#define RS_SOC_USER_CORE_COUNT 0U\n#define RS_SOC_USER_IP_COUNT 0U\n"
                 "#define RS_SOC_HAS_USER_CORES 0U\n#define RS_SOC_HAS_USER_IP_MUX 0U\n#endif\n")
    atomic_write(output / "include/retrosoc/generated/soc_features.h",
                 "#ifndef RETROSOC_GENERATED_SOC_FEATURES_H\n"
                 "#define RETROSOC_GENERATED_SOC_FEATURES_H\n"
                 "#define RS_SOC_TINY 1\n#define RS_SOC_HAS_PSRAM 0U\n"
                 "#define RS_SOC_DMA_CHANNELS 4U\n#define RS_SOC_ID 0x54494E59U\n#endif\n")
    gpio = [comment]
    for function in document["gpio_alt_functions"]:
        pin = function["pin"]
        for mode in ("alt0", "alt1"):
            value = function[mode]
            gpio.extend(f"assign {signal} = u_gpio_if.di_i[{pin}];" for signal in value["inputs"])
            gpio.extend((f"assign u_gpio_if.{mode}_do_i[{pin}] = {value['do']};",
                         f"assign u_gpio_if.{mode}_oe_i[{pin}] = {value['oe']};"))
    atomic_write(output / "rtl/tiny_gpio.svh", "\n".join(gpio) + "\n")
    ports, declarations, routes, decode = [], [comment], [comment], [comment]
    for index, target in enumerate(document["apb_targets"]):
        name = target["name"]
        ports.append(f"apb4_if.master {name}")
        declarations.append(f"apb4_if u_{name}_apb4_if (.pclk(clk_i), .presetn(s_rst_n));")
        routes.append(f".{name}(u_{name}_apb4_if)")
        decode.append(f"if ({' || '.join(f'`SOC_ADDR_IS_{r}(s_addr_q)' for r in target['regions'])}) "
                      f"s_select = {len(document['apb_targets'])}'b{1 << index:016b};")
    atomic_write(output / "rtl/tiny_apb_ports.svh", ",\n".join(ports) + "\n")
    atomic_write(output / "rtl/tiny_apb_interfaces.svh", "\n".join(declarations) + "\n")
    atomic_write(output / "rtl/tiny_apb_connections.svh", ",\n".join(routes[1:]) + "\n")
    atomic_write(output / "rtl/tiny_apb_decode.svh", "\n".join(decode) + "\n")
    wiring = [comment]
    for index, target in enumerate(document["apb_targets"]):
        name = target["name"]
        for field, value in {"paddr": "s_addr_q", "pwrite": "s_write_q",
                             "pwdata": "s_wdata_q", "pstrb": "s_wstrb_q", "pprot": "3'd0",
                             "psel": f"s_select[{index}] && s_access",
                             "penable": "s_enable"}.items():
            wiring.append(f"assign {name}.{field} = {value};")
        wiring.extend((f"assign s_ready[{index}] = {name}.pready;",
                       f"assign s_error[{index}] = {name}.pslverr;",
                       f"assign s_rdata[{index}] = {name}.prdata;"))
    atomic_write(output / "rtl/tiny_apb_wiring.svh", "\n".join(wiring) + "\n")


def generate_filelists(output: Path, generated: Path, defines: list[str]) -> None:
    prefixes = {"top": TINY / "top", "dv": TINY / "dv", "ip": ROOT / "rtl/ip",
                "tech": ROOT / "rtl/tech", "clusterip": ROOT / "rtl/managed/clusterip",
                "hazard3": ROOT / "rtl/managed/hazard3/hdl", "physical": ROOT / "physical"}
    templates = [*sorted((TINY / "filelist").glob("*.fl")),
                 ROOT / "rtl/filelist/pdk_ihp130.fl"]
    for template in templates:
        content = template.read_text()
        for prefix, directory in prefixes.items():
            content = re.sub(rf"(?<![^\s+])/{prefix}(?=/|\s|$)", str(directory), content)
        atomic_write(output / template.name, content)
    include = [generated / "rtl", generated / "memory_map/rtl", generated / "pin_map/rtl",
               generated / "archinfo"]
    atomic_write(output / "def.fl", " ".join([*defines, *(f"+incdir+{p}" for p in include)]) + "\n")
    atomic_write(output / "pdk_local.fl", "")


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--output", type=Path)
    parser.add_argument("--filelists", type=Path)
    parser.add_argument("--define", action="append", default=[])
    parser.add_argument("--check", action="store_true")
    args = parser.parse_args()
    document = read_topology(TINY / "integration/soc_topology.json",
                             TINY / "address_map/memory_map.json")
    if args.check:
        return 0
    if args.output is None or args.filelists is None:
        parser.error("--output and --filelists are required unless --check is used")
    if any(not value.startswith("+define+") for value in args.define):
        parser.error("--define requires a +define+ token")
    output = args.output.resolve()
    generate_memory_map(TINY / "address_map/memory_map.json", output / "memory_map", "YES", 128)
    generate_pin_map(TINY / "pin_map/pin_map.json", output / "pin_map")
    generate_bindings(document, output)
    generate_filelists(args.filelists.resolve(), output, args.define)
    return 0


if __name__ == "__main__":
    raise SystemExit(main())