src/modules/presets.py

"""
Preset Manager
==============
Allows users to save and load combinations of voice model + processing
settings so they don't have to re-configure everything for each run.

A preset stores:
- name, description, voice_model
- pitch, pitch_all, index_rate, filter_radius, rms_mix_rate, protect
- f0_method, crepe_hop_length, steps
- main_gain, backup_gain, inst_gain
- reverb_rm_size, reverb_wet, reverb_dry, reverb_damping
- output_format, extra_denoise

Presets are persisted as JSON in <BASE_DIR>/data/presets.json.
"""

import json
import os
import time
from typing import Any, Dict, List, Optional


PRESET_FIELDS = [
    "voice_model",
    "pitch",
    "pitch_all",
    "index_rate",
    "filter_radius",
    "rms_mix_rate",
    "protect",
    "f0_method",
    "crepe_hop_length",
    "steps",
    "main_gain",
    "backup_gain",
    "inst_gain",
    "reverb_rm_size",
    "reverb_wet",
    "reverb_dry",
    "reverb_damping",
    "output_format",
    "extra_denoise",
]


# Built-in starter presets that ship with the app
BUILTIN_PRESETS: List[Dict[str, Any]] = [
    {
        "name": "Default",
        "description": "Balanced settings suitable for most songs.",
        "voice_model": "",
        "pitch": 0,
        "pitch_all": 0,
        "index_rate": 0.5,
        "filter_radius": 3,
        "rms_mix_rate": 0.25,
        "protect": 0.33,
        "f0_method": "rmvpe+",
        "crepe_hop_length": 128,
        "steps": 1,
        "main_gain": 0,
        "backup_gain": 0,
        "inst_gain": 0,
        "reverb_rm_size": 0.15,
        "reverb_wet": 0.2,
        "reverb_dry": 0.8,
        "reverb_damping": 0.7,
        "output_format": "mp3",
        "extra_denoise": True,
        "builtin": True,
    },
    {
        "name": "Male -> Female",
        "description": "Pitch up by 12 semitones, smooth rmvpe detection.",
        "voice_model": "",
        "pitch": 1,
        "pitch_all": 0,
        "index_rate": 0.6,
        "filter_radius": 3,
        "rms_mix_rate": 0.25,
        "protect": 0.33,
        "f0_method": "rmvpe",
        "crepe_hop_length": 128,
        "steps": 1,
        "main_gain": 0,
        "backup_gain": 0,
        "inst_gain": 0,
        "reverb_rm_size": 0.15,
        "reverb_wet": 0.2,
        "reverb_dry": 0.8,
        "reverb_damping": 0.7,
        "output_format": "mp3",
        "extra_denoise": True,
        "builtin": True,
    },
    {
        "name": "Female -> Male",
        "description": "Pitch down by 12 semitones, extra protection.",
        "voice_model": "",
        "pitch": -1,
        "pitch_all": 0,
        "index_rate": 0.6,
        "filter_radius": 3,
        "rms_mix_rate": 0.3,
        "protect": 0.25,
        "f0_method": "rmvpe",
        "crepe_hop_length": 128,
        "steps": 1,
        "main_gain": 0,
        "backup_gain": 0,
        "inst_gain": 0,
        "reverb_rm_size": 0.18,
        "reverb_wet": 0.18,
        "reverb_dry": 0.82,
        "reverb_damping": 0.7,
        "output_format": "mp3",
        "extra_denoise": True,
        "builtin": True,
    },
    {
        "name": "Studio Quality",
        "description": "WAV output, mangio-crepe, max index rate.",
        "voice_model": "",
        "pitch": 0,
        "pitch_all": 0,
        "index_rate": 0.85,
        "filter_radius": 3,
        "rms_mix_rate": 0.25,
        "protect": 0.33,
        "f0_method": "mangio-crepe",
        "crepe_hop_length": 128,
        "steps": 2,
        "main_gain": 0,
        "backup_gain": 0,
        "inst_gain": 0,
        "reverb_rm_size": 0.12,
        "reverb_wet": 0.15,
        "reverb_dry": 0.85,
        "reverb_damping": 0.7,
        "output_format": "wav",
        "extra_denoise": True,
        "builtin": True,
    },
    {
        "name": "Karaoke Mode",
        "description": "Reduced reverb, clean dry vocals for karaoke.",
        "voice_model": "",
        "pitch": 0,
        "pitch_all": 0,
        "index_rate": 0.5,
        "filter_radius": 3,
        "rms_mix_rate": 0.25,
        "protect": 0.33,
        "f0_method": "rmvpe+",
        "crepe_hop_length": 128,
        "steps": 1,
        "main_gain": 2,
        "backup_gain": -3,
        "inst_gain": -2,
        "reverb_rm_size": 0.08,
        "reverb_wet": 0.08,
        "reverb_dry": 0.92,
        "reverb_damping": 0.6,
        "output_format": "mp3",
        "extra_denoise": True,
        "builtin": True,
    },
    {
        "name": "Concert Hall",
        "description": "Heavy reverb for a live-concert feel.",
        "voice_model": "",
        "pitch": 0,
        "pitch_all": 0,
        "index_rate": 0.5,
        "filter_radius": 3,
        "rms_mix_rate": 0.25,
        "protect": 0.33,
        "f0_method": "rmvpe+",
        "crepe_hop_length": 128,
        "steps": 1,
        "main_gain": 0,
        "backup_gain": 0,
        "inst_gain": 0,
        "reverb_rm_size": 0.55,
        "reverb_wet": 0.4,
        "reverb_dry": 0.6,
        "reverb_damping": 0.5,
        "output_format": "mp3",
        "extra_denoise": True,
        "builtin": True,
    },
]


class PresetManager:
    """Manages persistence and lookup of preset configurations."""

    def __init__(self, presets_path: str):
        self.path = presets_path
        self._ensure_file()

    def _ensure_file(self) -> None:
        if not os.path.exists(self.path):
            os.makedirs(os.path.dirname(self.path), exist_ok=True)
            self._write(BUILTIN_PRESETS)

    def _read(self) -> List[Dict[str, Any]]:
        try:
            with open(self.path, "r", encoding="utf-8") as f:
                return json.load(f)
        except (json.JSONDecodeError, OSError):
            return list(BUILTIN_PRESETS)

    def _write(self, presets: List[Dict[str, Any]]) -> None:
        os.makedirs(os.path.dirname(self.path), exist_ok=True)
        with open(self.path, "w", encoding="utf-8") as f:
            json.dump(presets, f, indent=2, ensure_ascii=False)

    def list_names(self) -> List[str]:
        return [p["name"] for p in self._read()]

    def get(self, name: str) -> Optional[Dict[str, Any]]:
        for p in self._read():
            if p["name"] == name:
                return p
        return None

    def save(self, name: str, description: str, **values) -> str:
        name = (name or "").strip()
        if not name:
            return "Error: preset name is required."
        presets = self._read()
        # Build the preset from provided values (only keep known fields)
        preset: Dict[str, Any] = {
            "name": name,
            "description": description or "",
            "builtin": False,
            "created_at": int(time.time()),
        }
        for field in PRESET_FIELDS:
            preset[field] = values.get(field, None)
        # Replace if exists (but never overwrite builtin)
        new_list = []
        replaced = False
        for p in presets:
            if p["name"] == name:
                if p.get("builtin"):
                    return f"Error: cannot overwrite built-in preset '{name}'."
                new_list.append(preset)
                replaced = True
            else:
                new_list.append(p)
        if not replaced:
            new_list.append(preset)
        self._write(new_list)
        return f"Saved preset '{name}'."

    def delete(self, name: str) -> str:
        presets = self._read()
        new_list = []
        deleted = False
        for p in presets:
            if p["name"] == name:
                if p.get("builtin"):
                    return f"Error: cannot delete built-in preset '{name}'."
                deleted = True
                continue
            new_list.append(p)
        if not deleted:
            return f"Error: preset '{name}' not found."
        self._write(new_list)
        return f"Deleted preset '{name}'."

    def reset_builtin(self) -> str:
        """Restore the built-in presets (keeps user presets)."""
        presets = self._read()
        names = {p["name"] for p in presets if not p.get("builtin")}
        new_list = [p for p in presets if not p.get("builtin")] + list(BUILTIN_PRESETS)
        self._write(new_list)
        return f"Restored {len(BUILTIN_PRESETS)} built-in presets ({len(names)} user presets kept)."