{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://beats.bitwrap.io/schema/petri-note.schema.json",
  "title": "PetriNote Project Schema",
  "description": "Schema for Petri net music sequencer projects. Each project contains a collection of Petri nets where tokens flow through places and transitions fire to trigger MIDI notes.",

  "definitions": {

    "MidiBinding": {
      "type": "object",
      "description": "MIDI note binding on a transition — fires when the transition fires",
      "properties": {
        "note": {
          "type": "integer",
          "minimum": 0,
          "maximum": 127,
          "description": "MIDI note number (60 = C4)"
        },
        "velocity": {
          "type": "integer",
          "minimum": 0,
          "maximum": 127,
          "default": 100
        },
        "duration": {
          "type": "integer",
          "minimum": 0,
          "description": "Duration in milliseconds"
        },
        "channel": {
          "type": "integer",
          "minimum": 1,
          "maximum": 16,
          "description": "MIDI channel (overrides track default)"
        }
      },
      "required": ["note"]
    },

    "ControlBinding": {
      "type": "object",
      "description": "Control binding on a transition — controls mute state of other nets",
      "properties": {
        "action": {
          "type": "string",
          "enum": ["mute-track", "unmute-track", "toggle-track", "activate-slot", "stop-transport"],
          "description": "Control action to perform"
        },
        "targetNet": {
          "type": "string",
          "description": "Target net ID to control"
        },
        "targetNote": {
          "type": "integer",
          "minimum": 0,
          "maximum": 127,
          "description": "Target MIDI note (for note-level muting)"
        }
      },
      "required": ["action"]
    },

    "Place": {
      "type": "object",
      "description": "A place in the Petri net (holds tokens)",
      "properties": {
        "label": { "type": "string" },
        "initial": {
          "type": "array",
          "items": { "type": "number" },
          "default": [0],
          "description": "Initial token count"
        },
        "x": { "type": "number", "default": 0 },
        "y": { "type": "number", "default": 0 }
      }
    },

    "Transition": {
      "type": "object",
      "description": "A transition in the Petri net (fires when all input places have sufficient tokens)",
      "properties": {
        "label": { "type": "string" },
        "x": { "type": "number", "default": 0 },
        "y": { "type": "number", "default": 0 },
        "midi": {
          "$ref": "#/definitions/MidiBinding",
          "description": "MIDI note to play when transition fires"
        },
        "control": {
          "$ref": "#/definitions/ControlBinding",
          "description": "Control event to fire (for control nets)"
        }
      }
    },

    "Arc": {
      "type": "object",
      "description": "An arc connecting a place and transition",
      "properties": {
        "source": { "type": "string", "description": "Source node ID (place or transition)" },
        "target": { "type": "string", "description": "Target node ID (place or transition)" },
        "weight": {
          "type": "array",
          "items": { "type": "number" },
          "default": [1],
          "description": "Token weight consumed/produced"
        },
        "inhibit": {
          "type": "boolean",
          "default": false,
          "description": "If true, blocks transition when source has >= weight tokens"
        }
      },
      "required": ["source", "target"]
    },

    "MixSettings": {
      "type": "object",
      "description": "Per-track mixer settings (saved in downloaded files)",
      "properties": {
        "volume": { "type": "integer", "minimum": 0, "maximum": 127, "default": 127 },
        "pan": { "type": "integer", "minimum": 0, "maximum": 127, "default": 64 },
        "loCut": { "type": "integer", "minimum": 0, "maximum": 100, "default": 0 },
        "loResonance": { "type": "integer", "minimum": 0, "maximum": 100, "default": 5 },
        "cutoff": { "type": "integer", "minimum": 0, "maximum": 100, "default": 100 },
        "resonance": { "type": "integer", "minimum": 0, "maximum": 100, "default": 5 },
        "decay": { "type": "integer", "minimum": 5, "maximum": 300, "default": 5 }
      }
    },

    "Track": {
      "type": "object",
      "description": "Track/channel assignment for a net. Recipe fields (generator, ringSize, beats, rotation, note, generatorParams) describe how the net was originally constructed so it can be regenerated at a different size in place.",
      "properties": {
        "channel": {
          "type": "integer",
          "minimum": 1,
          "maximum": 16,
          "default": 1,
          "description": "MIDI channel (10 = drums by convention)"
        },
        "defaultVelocity": {
          "type": "integer",
          "minimum": 0,
          "maximum": 127,
          "default": 100,
          "description": "Base velocity used when a binding omits its own"
        },
        "instrument": {
          "type": "string",
          "description": "Instrument name (e.g. 'piano', 'drums-v8', 'acid')"
        },
        "instrumentSet": {
          "type": "array",
          "items": { "type": "string" },
          "description": "Available instruments for this track role"
        },
        "mix": {
          "$ref": "#/definitions/MixSettings",
          "description": "Mixer slider state (persisted on download)"
        },
        "generator": {
          "type": "string",
          "enum": ["euclidean", "euclidean-ghost", "euclidean-melodic", "markov", "walking-bass", "call-response"],
          "description": "Which generator built this net. Needed to rebuild the ring when size/hits change."
        },
        "ringSize": {
          "type": "integer",
          "minimum": 2,
          "maximum": 32,
          "description": "Number of places in the ring (n). The mixer Size dropdown edits this."
        },
        "beats": {
          "type": "integer",
          "minimum": 0,
          "maximum": 32,
          "description": "Number of hits (k) for Euclidean generators, or count of non-rest steps for melodic ones. The mixer Hits dropdown edits this."
        },
        "rotation": {
          "type": "integer",
          "description": "Euclidean rotation offset; unused for melodic generators"
        },
        "note": {
          "type": "integer",
          "minimum": 0,
          "maximum": 127,
          "description": "Base MIDI note for Euclidean drum bindings; unused for melodic generators"
        },
        "generatorParams": {
          "type": "object",
          "description": "Opaque bag of the generator's recipe inputs (scale, rootNote, chords, seed, duration, syncopation, durationVariation, ghostDensity, accent) — consumed by regenerateTrack() to rebuild an equivalent net at a new size",
          "additionalProperties": true
        }
      }
    },

    "Net": {
      "type": "object",
      "description": "A single Petri net — tokens circulate through places, transitions fire to produce MIDI notes or control events",
      "properties": {
        "role": {
          "type": "string",
          "enum": ["music", "control"],
          "default": "music",
          "description": "music = produces MIDI notes, control = mutes/unmutes other nets"
        },
        "riffGroup": {
          "type": "string",
          "description": "Groups variant nets (e.g. 'kick' for kick-0, kick-1). Mixer shows one row per group."
        },
        "riffVariant": {
          "type": "string",
          "description": "Variant label within a riff group (e.g. 'A', 'B')"
        },
        "track": { "$ref": "#/definitions/Track" },
        "places": {
          "type": "object",
          "additionalProperties": { "$ref": "#/definitions/Place" },
          "description": "Places keyed by ID (e.g. 'p0', 'p1')"
        },
        "transitions": {
          "type": "object",
          "additionalProperties": { "$ref": "#/definitions/Transition" },
          "description": "Transitions keyed by ID (e.g. 't0', 't1')"
        },
        "arcs": {
          "type": "array",
          "items": { "$ref": "#/definitions/Arc" }
        }
      },
      "required": ["places", "transitions", "arcs"]
    },

    "StructureSection": {
      "type": "object",
      "description": "A section of song structure (used for timeline display and control net generation)",
      "properties": {
        "name": {
          "type": "string",
          "description": "Section type (intro, verse, chorus, drop, bridge, breakdown, buildup, outro)"
        },
        "steps": {
          "type": "integer",
          "minimum": 1,
          "description": "Duration in ticks (16 ticks = 1 bar at PPQ=4)"
        },
        "phrases": {
          "type": "object",
          "additionalProperties": {
            "type": "array",
            "items": { "type": "string" }
          },
          "description": "Phrase variant sequence per role, e.g. {\"kick\": [\"A\",\"A\",\"B\",\"A\"]}"
        }
      },
      "required": ["name", "steps"]
    },

    "FxSettings": {
      "type": "object",
      "description": "Master FX settings (saved in downloaded files)",
      "properties": {
        "masterVol": { "type": "integer", "minimum": 0, "maximum": 100, "default": 80, "description": "Master volume (0-100, maps to -60..0 dB)" },
        "reverbSize": { "type": "integer", "minimum": 0, "maximum": 100, "default": 50 },
        "reverbDamp": { "type": "integer", "minimum": 0, "maximum": 100, "default": 30 },
        "reverbWet": { "type": "integer", "minimum": 0, "maximum": 100, "default": 20 },
        "delayTime": { "type": "integer", "minimum": 1, "maximum": 100, "default": 25, "description": "Delay time as percentage (maps to 0.01-1.0s)" },
        "delayFeedback": { "type": "integer", "minimum": 0, "maximum": 90, "default": 25 },
        "delayWet": { "type": "integer", "minimum": 0, "maximum": 100, "default": 15 },
        "distortion": { "type": "integer", "minimum": 0, "maximum": 100, "default": 0 },
        "hpFreq": { "type": "integer", "minimum": 0, "maximum": 100, "default": 0, "description": "High-pass filter (0=20Hz, 100=5kHz, exponential)" },
        "lpFreq": { "type": "integer", "minimum": 0, "maximum": 100, "default": 100, "description": "Low-pass filter (0=100Hz, 100=20kHz, exponential)" },
        "phaserFreq": { "type": "integer", "minimum": 0, "maximum": 100, "default": 0, "description": "Phaser rate (0=off, maps to 0.1-10Hz)" },
        "phaserDepth": { "type": "integer", "minimum": 0, "maximum": 100, "default": 50 },
        "phaserWet": { "type": "integer", "minimum": 0, "maximum": 100, "default": 0 },
        "crushBits": { "type": "integer", "minimum": 0, "maximum": 100, "default": 0, "description": "Bit crusher (0=off, maps to 16-bit down to 1-bit)" }
      }
    }
  },

  "type": "object",
  "properties": {
    "name": {
      "type": "string",
      "default": "Untitled",
      "description": "Project name (e.g. 'techno · Hollow Arc')"
    },
    "tempo": {
      "type": "number",
      "minimum": 20,
      "maximum": 300,
      "default": 120,
      "description": "Global tempo in BPM"
    },
    "swing": {
      "type": "number",
      "minimum": 0,
      "maximum": 100,
      "default": 0,
      "description": "Swing percentage (0 = straight)"
    },
    "humanize": {
      "type": "number",
      "minimum": 0,
      "maximum": 100,
      "default": 0,
      "description": "Humanize amount: timing jitter and velocity variation"
    },
    "nets": {
      "type": "object",
      "additionalProperties": { "$ref": "#/definitions/Net" },
      "description": "All Petri nets keyed by ID (e.g. 'kick-0', 'bass-1', 'struct-kick')"
    },
    "structure": {
      "type": "array",
      "items": { "$ref": "#/definitions/StructureSection" },
      "description": "Song structure sections for timeline display. Omit for loop mode."
    },
    "initialMutes": {
      "type": "array",
      "items": { "type": "string" },
      "description": "Net IDs that start muted (inactive phrase variants, intro silences)"
    },
    "fx": {
      "$ref": "#/definitions/FxSettings",
      "description": "Master FX state (persisted on download)"
    }
  },
  "required": ["name", "nets"]
}