#!/usr/bin/env python3
"""
convert_all.py — Convert all .txt show files and regenerate shows.h.

Reads every .txt file in converter/shows/, converts each one to a
show_<name>.h header, and regenerates arduino/cosplay_lights/shows.h
with the updated SHOWS[] index.

Usage:
    python converter/convert_all.py
    (or via Makefile: make shows)

Show 0 is always 'blue_pulse' — the home/reset show.
All other shows are sorted alphabetically and follow after it.

SPDX-License-Identifier: BSD-2-Clause
"""

import re
import sys
from pathlib import Path


# Paths relative to this script's location
SCRIPT_DIR  = Path(__file__).parent
ROOT_DIR    = SCRIPT_DIR.parent
SHOWS_DIR   = SCRIPT_DIR / "shows"
SKETCH_DIR  = ROOT_DIR / "arduino" / "cosplay_lights"

# The special first show — always placed at index 0.
HOME_SHOW = "blue_pulse"

# Regex to match a valid step line: #RRGGBB, duration_ms
STEP_PATTERN = re.compile(r'^\s*#([0-9A-Fa-f]{6})\s*,\s*(\d+)')


# ---- Helpers -----------------------------------------------------------

def filename_to_symbol(stem: str) -> str:
    """Convert a filename stem to an uppercase C array symbol. e.g. 'example_fade' → 'SHOW_EXAMPLE_FADE'"""
    clean = re.sub(r'[^a-zA-Z0-9]', '_', stem)
    return "SHOW_" + clean.upper()


def hex_to_rgb(hex_str: str) -> tuple[int, int, int]:
    return int(hex_str[0:2], 16), int(hex_str[2:4], 16), int(hex_str[4:6], 16)


def parse_show(filepath: Path) -> list[tuple[int, int, int, int]]:
    """
    Parse a .txt show file. Returns list of (r, g, b, duration_ms) tuples.
    Raises ValueError on malformed lines.
    """
    steps = []
    with open(filepath) as f:
        for lineno, raw_line in enumerate(f, 1):
            line = raw_line.split("//")[0].strip()
            if not line:
                continue
            match = STEP_PATTERN.match(line)
            if not match:
                raise ValueError(
                    f"{filepath.name} line {lineno}: "
                    f"expected '#RRGGBB, duration_ms' but got: {raw_line.rstrip()!r}"
                )
            r, g, b  = hex_to_rgb(match.group(1))
            duration = int(match.group(2))
            steps.append((r, g, b, duration))
    if not steps:
        raise ValueError(f"{filepath.name}: file contains no steps.")
    return steps


def render_show_header(steps: list, source_name: str, symbol: str) -> str:
    """Render a show as a C++ header file."""
    lines = [
        f"// Generated by convert_all.py from: {source_name}",
        "// Do not edit manually — edit the .txt file and run: make shows",
        "// SPDX-License-Identifier: BSD-2-Clause",
        "",
        "#pragma once",
        '#include "lightshow_format.h"',
        "",
        f"const Step {symbol}[] PROGMEM = {{",
    ]
    for r, g, b, dur in steps:
        hex_color = f"#{r:02X}{g:02X}{b:02X}"
        lines.append(f"    {{{r:3d}, {g:3d}, {b:3d}, {dur:5d}}},  // {hex_color}, {dur}ms")
    lines += [
        "};",
        f"const uint16_t {symbol}_LENGTH = {len(steps)};",
        "",
    ]
    return "\n".join(lines)


def render_shows_index(ordered_stems: list[str]) -> str:
    """Render the master shows.h index file."""
    includes = "\n".join(f'#include "show_{stem}.h"' for stem in ordered_stems)
    entries  = "\n".join(
        f"    {{{filename_to_symbol(s)}, {filename_to_symbol(s)}_LENGTH}},"
        + ("  // 0 — home show" if i == 0 else f"  // {i}")
        for i, s in enumerate(ordered_stems)
    )
    count = len(ordered_stems)
    return f"""\
// =====================================================================
// shows.h — Master show index.
// Generated by: make shows  (converter/convert_all.py)
// Do not edit manually — add .txt files to converter/shows/ instead.
// =====================================================================
//
// Show 0 is always the home/reset show (slow blue pulse).
// Holding the button resets back to show 0.
//
// SPDX-License-Identifier: BSD-2-Clause

#pragma once
#include "lightshow_format.h"

// ---- Individual show data ----------------------------------------------
{includes}

// ---- Show index (PROGMEM) ----------------------------------------------
const ShowDef SHOWS[] PROGMEM = {{
{entries}
}};

const uint8_t SHOW_COUNT = {count};
"""


# ---- Main --------------------------------------------------------------

def main() -> None:
    txt_files = sorted(SHOWS_DIR.glob("*.txt"))
    if not txt_files:
        print(f"No .txt files found in {SHOWS_DIR}")
        sys.exit(1)

    # Separate the home show from the rest; sort the rest alphabetically.
    home_file   = SHOWS_DIR / f"{HOME_SHOW}.txt"
    other_files = [f for f in txt_files if f.stem != HOME_SHOW]

    if not home_file.exists():
        print(f"Warning: home show '{HOME_SHOW}.txt' not found — show 0 will be {txt_files[0].name}")
        ordered_files = txt_files
    else:
        ordered_files = [home_file] + other_files

    SKETCH_DIR.mkdir(parents=True, exist_ok=True)

    converted = []
    errors    = []

    for txt_path in ordered_files:
        stem   = txt_path.stem
        symbol = filename_to_symbol(stem)
        try:
            steps  = parse_show(txt_path)
            header = render_show_header(steps, txt_path.name, symbol)
            out    = SKETCH_DIR / f"show_{stem}.h"
            out.write_text(header, encoding="utf-8")
            print(f"  OK  {txt_path.name}  →  show_{stem}.h  ({len(steps)} steps)")
            converted.append(stem)
        except ValueError as e:
            print(f"  ERR {e}")
            errors.append(stem)

    if errors:
        print(f"\n{len(errors)} file(s) had errors and were skipped.")

    if not converted:
        print("No shows converted — shows.h not updated.")
        sys.exit(1)

    # Regenerate shows.h
    index_path = SKETCH_DIR / "shows.h"
    index_path.write_text(render_shows_index(converted), encoding="utf-8")
    print(f"\n  OK  shows.h updated  ({len(converted)} shows, show 0 = {converted[0]})")
    print(      "      Run 'make upload' to compile and send to the Arduino.")


if __name__ == "__main__":
    main()