{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://jbhoorasingh.github.io/gt7-datalogger/reference/schemas/track-compiled.v1.schema.json",
  "title": "GT7 datalogger compiled track geometry (format v1)",
  "description": "Derived vector geometry compiled from a track bundle's border evidence: ordered border polylines, centerline with width and elevation, the road surface as quads, flagged survey gaps, and boundary-length coverage. Recomputed locally whenever the bundle changes; never imported. Stored at data/track-bundles/compiled/<slug>.json.",
  "type": "object",
  "required": ["format", "version", "track", "slug", "borders", "centerline", "road", "coverage"],
  "properties": {
    "format": { "const": "gt7-datalogger-track-compiled" },
    "version": { "const": 1 },
    "track": { "type": "string", "minLength": 1, "maxLength": 80 },
    "slug": { "type": "string", "maxLength": 80 },
    "compiled_at": { "type": "string", "maxLength": 64 },
    "source": {
      "type": "object",
      "description": "Provenance: the evidence this geometry was compiled from.",
      "properties": {
        "points": { "type": "integer", "minimum": 0 },
        "runs": { "type": "integer", "minimum": 0 },
        "sources": { "type": "integer", "minimum": 0 },
        "bundle_updated_at": { "type": "string", "maxLength": 64 },
        "app_version": { "type": "string", "maxLength": 32 }
      }
    },
    "borders": {
      "type": "object",
      "description": "Ordered border polylines per side, split at survey gaps, Douglas-Peucker simplified. Vertices are [x, z, y]; y is null where the metre predates elevation capture.",
      "required": ["L", "R"],
      "properties": {
        "L": { "$ref": "#/$defs/polylines3" },
        "R": { "$ref": "#/$defs/polylines3" }
      }
    },
    "gaps": {
      "type": "object",
      "description": "Unsurveyed spans the ordering bridged, as [x1, z1, x2, z2] segments. Excluded from the drawn borders and counted against coverage.",
      "properties": {
        "L": { "$ref": "#/$defs/segments" },
        "R": { "$ref": "#/$defs/segments" }
      }
    },
    "walls": {
      "$ref": "#/$defs/segments",
      "description": "Border cells whose votes settled on 'wall', as short ticks: a line that ran wide into a barrier reads differently from one that ran wide over paint."
    },
    "centerline": {
      "type": "array",
      "description": "Polyline runs of [x, z, y, w]: the road's middle, its elevation (null when neither border knows it) and its measured width. Runs break where either border is unsurveyed.",
      "items": {
        "type": "array",
        "minItems": 2,
        "items": {
          "type": "array",
          "prefixItems": [
            { "type": "number" },
            { "type": "number" },
            { "oneOf": [{ "type": "null" }, { "type": "number" }] },
            { "type": "number", "minimum": 0 }
          ],
          "minItems": 4,
          "maxItems": 4
        }
      }
    },
    "road": {
      "type": "array",
      "description": "The road surface between the border curves as convex quads [x1,z1,x2,z2,x3,z3,x4,z4], adjacent quads sharing edges.",
      "items": {
        "type": "array",
        "items": { "type": "number" },
        "minItems": 8,
        "maxItems": 8
      }
    },
    "finish": {
      "oneOf": [
        { "type": "null" },
        { "type": "array", "items": { "type": "number" }, "minItems": 4, "maxItems": 4 }
      ],
      "description": "The start/finish line as [x1, z1, x2, z2], averaged from recorded lap rollovers."
    },
    "coverage": {
      "type": "object",
      "description": "Coverage measured against the boundary itself, not the driven trail. closed says whether the side's main chain forms a loop - only then is the denominator the whole lap.",
      "required": ["L", "R", "road_pct"],
      "properties": {
        "L": { "$ref": "#/$defs/sideCoverage" },
        "R": { "$ref": "#/$defs/sideCoverage" },
        "road_pct": {
          "type": "number", "minimum": 0, "maximum": 100,
          "description": "Share of surveyed left-border metres with the right border found across from them - how much of the road surface is resolved."
        }
      }
    },
    "_bundle_identity": {
      "type": "array",
      "description": "Internal staleness key: [mtime_ns, size] of the bundle file this was compiled from.",
      "items": { "type": "integer" },
      "minItems": 2,
      "maxItems": 2
    }
  },
  "$defs": {
    "polylines3": {
      "type": "array",
      "items": {
        "type": "array",
        "minItems": 2,
        "items": {
          "type": "array",
          "prefixItems": [
            { "type": "number" },
            { "type": "number" },
            { "oneOf": [{ "type": "null" }, { "type": "number" }] }
          ],
          "minItems": 3,
          "maxItems": 3
        }
      }
    },
    "segments": {
      "type": "array",
      "items": {
        "type": "array",
        "items": { "type": "number" },
        "minItems": 4,
        "maxItems": 4
      }
    },
    "sideCoverage": {
      "type": "object",
      "required": ["surveyed_m", "gap_m", "pct", "closed"],
      "properties": {
        "surveyed_m": { "type": "number", "minimum": 0 },
        "gap_m": { "type": "number", "minimum": 0 },
        "pct": { "type": "number", "minimum": 0, "maximum": 100 },
        "closed": { "type": "boolean" }
      }
    }
  }
}