{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://open-dj.org/schema/0.2/open-dj.schema.json",
  "title": "open-dj v0.2 library schema",
  "description": "Root schema for open-dj v0.2 documents.",
  "type": "object",
  "properties": {
    "schema_version": { "const": "0.2" },
    "kind": { "enum": ["library", "track", "playlist", "session"] },
    "tracks":    { "type": "array", "items": { "$ref": "#/$defs/Track" } },
    "playlists": { "type": "array", "items": { "$ref": "#/$defs/Playlist" } },
    "pairings":  { "type": "array", "items": { "$ref": "#/$defs/Pairing" } },
    "sessions":  { "type": "array", "items": { "$ref": "#/$defs/Session" } }
  },
  "required": ["schema_version", "kind"],
  "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
  "unevaluatedProperties": false,
  "$defs": {
    "ProvenanceValue": {
      "title": "ProvenanceValue",
      "type": "object",
      "required": ["value", "source", "modified_at"],
      "properties": {
        "value": {},
        "source": {
          "enum": ["mik", "rekordbox", "djay", "serato", "traktor",
                    "open-dj-tool", "manual", "inferred"]
        },
        "confidence": { "type": "number", "minimum": 0, "maximum": 1 },
        "modified_at": { "type": "string", "format": "date-time" }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": true
    },
    "Track": {
      "title": "Track",
      "type": "object",
      "required": ["track_id", "title", "artists", "duration_ms",
                   "file_path", "content_hash"],
      "properties": {
        "track_id":     { "type": "string", "pattern": "^[0-9a-f]{40}$" },
        "title":        { "type": "string" },
        "artists":      { "type": "array", "items": { "type": "string" } },
        "album":        { "type": "string" },
        "isrc":         { "type": "string", "pattern": "^[A-Z]{2}[A-Z0-9]{3}[0-9]{7}$" },
        "duration_ms":  { "type": "integer", "minimum": 0 },
        "file_path":    { "type": "string" },
        "content_hash": { "type": "string", "pattern": "^sha256:[0-9a-f]{64}$" },
        "size_bytes":   { "type": "integer", "minimum": 0 },
        "bpm":          { "$ref": "#/$defs/ProvenanceValue" },
        "key":          { "$ref": "#/$defs/ProvenanceValue" },
        "energy":       { "$ref": "#/$defs/ProvenanceValue" },
        "rating":       { "$ref": "#/$defs/ProvenanceValue" },
        "cue_points":   { "type": "array", "items": { "$ref": "#/$defs/CuePoint" } },
        "beatgrid":     { "$ref": "#/$defs/BeatGrid" },
        "vendor_ids":   {
          "type": "object",
          "additionalProperties": { "type": "string" }
        }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": false
    },
    "CuePoint": {
      "title": "CuePoint",
      "type": "object",
      "required": ["position_ms", "type"],
      "properties": {
        "position_ms": { "type": "integer", "minimum": 0 },
        "type": {
          "enum": ["hot", "memory", "loop_in", "loop_out",
                    "grid", "fade_in", "fade_out", "load"]
        },
        "slot":      { "type": "integer", "minimum": 0, "maximum": 31 },
        "name":      { "type": "string" },
        "color":     { "type": "string", "pattern": "^#[0-9a-fA-F]{6}$" },
        "length_ms": { "type": "integer", "minimum": 0 },
        "source":    { "$ref": "#/$defs/ProvenanceValue" }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": false
    },
    "BeatGrid": {
      "title": "BeatGrid",
      "type": "object",
      "required": ["origin_ms", "bpm"],
      "properties": {
        "origin_ms": { "type": "number" },
        "bpm":       { "type": "number", "minimum": 1 },
        "version":   { "type": "integer", "minimum": 1, "default": 1 },
        "algorithm": { "enum": ["constant", "variable", "manual", "unknown"] },
        "beats": {
          "type": "array",
          "items": { "type": "number" }
        },
        "source":    { "$ref": "#/$defs/ProvenanceValue" }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": false
    },
    "Playlist": {
      "title": "Playlist",
      "type": "object",
      "required": ["playlist_id", "name", "tracks_ordered"],
      "properties": {
        "playlist_id":    { "type": "string" },
        "parent_id":      { "type": "string" },
        "name":           { "type": "string" },
        "tracks_ordered": {
          "type": "array",
          "items": { "type": "string", "pattern": "^[0-9a-f]{40}$" }
        },
        "play_orders": {
          "type": "array",
          "items": { "$ref": "#/$defs/PlayOrder" }
        }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": false
    },
    "PlayOrder": {
      "title": "PlayOrder",
      "type": "object",
      "required": ["name", "entries"],
      "properties": {
        "name": { "type": "string" },
        "entries": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["track_id", "position"],
            "properties": {
              "track_id":     { "type": "string", "pattern": "^[0-9a-f]{40}$" },
              "position":     { "type": "integer", "minimum": 0 },
              "target_key":   { "type": "string" },
              "target_tempo": { "type": "number" },
              "key_sync":     { "type": "boolean" }
            },
            "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
            "additionalProperties": false
          }
        }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": false
    },
    "Pairing": {
      "title": "Pairing",
      "type": "object",
      "required": ["from_track_id", "to_track_id", "direction", "source"],
      "properties": {
        "from_track_id": { "type": "string", "pattern": "^[0-9a-f]{40}$" },
        "to_track_id":   { "type": "string", "pattern": "^[0-9a-f]{40}$" },
        "direction":     { "enum": ["into", "out_of", "either"] },
        "source":        { "enum": ["manual", "learned", "ai"] },
        "notes":         { "type": "string" },
        "confidence":    { "type": "number", "minimum": 0, "maximum": 1 }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": false
    },
    "Session": {
      "title": "Session",
      "type": "object",
      "required": ["session_id", "started_at", "events"],
      "properties": {
        "session_id":  { "type": "string" },
        "name":        { "type": "string" },
        "started_at":  { "type": "string", "format": "date-time" },
        "ended_at":    { "type": "string", "format": "date-time" },
        "events": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["timestamp", "deck", "action"],
            "properties": {
              "timestamp": { "type": "string", "format": "date-time" },
              "deck":      { "type": "integer", "minimum": 1 },
              "track_id":  { "type": "string", "pattern": "^[0-9a-f]{40}$" },
              "action":    { "enum": ["load","play","pause","cue","seek",
                                       "fader","eq","fx","tempo"] },
              "value":     {}
            },
            "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
            "additionalProperties": false
          }
        },
        "transitions": {
          "type": "array",
          "items": { "$ref": "#/$defs/Transition" }
        }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": false
    },
    "Transition": {
      "title": "Transition",
      "type": "object",
      "required": ["at", "from_deck", "to_deck", "class"],
      "properties": {
        "at":            { "type": "string", "format": "date-time" },
        "from_deck":     { "type": "integer" },
        "to_deck":       { "type": "integer" },
        "from_track_id": { "type": "string", "pattern": "^[0-9a-f]{40}$" },
        "to_track_id":   { "type": "string", "pattern": "^[0-9a-f]{40}$" },
        "class":         { "enum": ["cut","blend","filter_sweep","fx","quick_double"] },
        "duration_ms":   { "type": "integer", "minimum": 0 }
      },
      "patternProperties": { "^x_[a-z0-9][a-z0-9_]*$": {} },
      "additionalProperties": false
    }
  }
}