"""
Constants and enums for the music system.
No magic strings - use enums and Literal types for constrained values.
"""
from enum import Enum, IntEnum
from typing import Literal
class LayerRole(str, Enum):
"""
Frequency/function hierarchy for layers.
This is how producers think about arrangement.
"""
SUB = "sub" # Sub bass (20-60 Hz)
BASS = "bass" # Bass (60-250 Hz)
DRUMS = "drums" # Rhythm section
HARMONY = "harmony" # Chords, pads
MELODY = "melody" # Lead lines
FX = "fx" # Risers, impacts, ear candy
VOCAL = "vocal" # Voice
class GMDrumNote(IntEnum):
"""General MIDI drum note numbers."""
KICK = 36
KICK_2 = 35
SNARE = 38
SNARE_2 = 40
CLAP = 39
CLOSED_HIHAT = 42
OPEN_HIHAT = 46
PEDAL_HIHAT = 44
RIDE = 51
CRASH = 49
TOM_LOW = 41
TOM_MID = 47
TOM_HIGH = 50
# Default MIDI channel assignments by role
DEFAULT_CHANNEL_MAP: dict[LayerRole, int] = {
LayerRole.SUB: 0,
LayerRole.BASS: 1,
LayerRole.DRUMS: 9, # GM drums
LayerRole.HARMONY: 2,
LayerRole.MELODY: 3,
LayerRole.FX: 4,
LayerRole.VOCAL: 5,
}
# Default MIDI register (octave range) by role
DEFAULT_REGISTER_MAP: dict[LayerRole, tuple[int, int]] = {
LayerRole.SUB: (24, 36), # C1-C2
LayerRole.BASS: (36, 52), # C2-E3
LayerRole.DRUMS: (36, 84), # GM drum range
LayerRole.HARMONY: (48, 72), # C3-C5
LayerRole.MELODY: (60, 84), # C4-C6
LayerRole.FX: (0, 127), # Unconstrained
LayerRole.VOCAL: (48, 84), # C3-C6
}
# Schema versions - frozen for v1
SchemaVersion = Literal[
"project/v1",
"arrangement/v1",
"pattern/v1",
"instance/v1",
"events/v1",
"harmony/v1",
"style/v1",
"operation/v1",
"pattern-test/v1",
]
# Energy levels (semantic tokens)
EnergyLevel = Literal["minimal", "low", "medium", "high", "peak"]
# Density levels
DensityLevel = Literal["sparse", "moderate", "dense", "very_dense"]
class ErrorMessages:
"""Standardized error messages."""
NO_ARRANGEMENT = "No arrangement found. Create one first."
ARRANGEMENT_NOT_FOUND = "Arrangement '{name}' not found."
PATTERN_NOT_FOUND = "Pattern '{pattern_id}' not found."
LAYER_NOT_FOUND = "Layer '{layer}' not found in arrangement."
SECTION_NOT_FOUND = "Section '{section}' not found in arrangement."
INVALID_KEY = "Invalid key: '{key}'. Expected format like 'C_major' or 'D_minor'."
INVALID_TEMPO = "Invalid tempo: {tempo}. Must be between 40 and 240 BPM."
class SuccessMessages:
"""Standardized success messages."""
ARRANGEMENT_CREATED = "Created arrangement '{name}'."
ARRANGEMENT_COMPILED = "Compiled arrangement '{name}' to {path}."
PATTERN_ADDED = "Added pattern '{pattern_id}' to layer '{layer}'."
SECTION_ADDED = "Added section '{section}' ({bars} bars)."
