{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://openhydro.org/schemas/v1/terrain_2d.schema.json",
  "title": "Benchmark1d2d 2D Terrain",
  "description": "Minimal 2D terrain description: mesh or raster elevation references, roughness, and boundary conditions.",
  "type": "object",
  "additionalProperties": false,
  "required": ["schema_version", "elevation", "boundary_conditions"],
  "properties": {
    "schema_version": {
      "type": "string",
      "pattern": "^(0|[1-9]\\d*)\\.(0|[1-9]\\d*)\\.(0|[1-9]\\d*)(?:-[0-9A-Za-z-]+(?:\\.[0-9A-Za-z-]+)*)?(?:\\+[0-9A-Za-z-]+(?:\\.[0-9A-Za-z-]+)*)?$"
    },
    "crs": {
      "type": "string",
      "description": "CRS (EPSG code or WKT)."
    },
    "elevation": {
      "$ref": "#/$defs/surface_ref"
    },
    "mesh": {
      "$ref": "#/$defs/mesh_ref"
    },
    "roughness": {
      "$ref": "#/$defs/roughness"
    },
    "boundary_conditions": {
      "type": "array",
      "minItems": 1,
      "items": { "$ref": "#/$defs/boundary_condition" }
    },
    "initial_condition": {
      "type": "object",
      "additionalProperties": false,
      "properties": {
        "kind": {
          "type": "string",
          "enum": ["dry", "constant_depth", "raster", "file"]
        },
        "depth": { "type": "number", "minimum": 0 },
        "path": { "type": "string" },
        "sha256": {
          "type": "string",
          "pattern": "^[a-fA-F0-9]{64}$"
        }
      }
    }
  },
  "$defs": {
    "surface_ref": {
      "type": "object",
      "additionalProperties": false,
      "required": ["kind"],
      "properties": {
        "kind": {
          "type": "string",
          "enum": ["raster", "mesh", "analytic"]
        },
        "path": { "type": "string" },
        "sha256": {
          "type": "string",
          "pattern": "^[a-fA-F0-9]{64}$"
        },
        "format": {
          "type": "string",
          "enum": ["geotiff", "ugrid", "netcdf", "xyz", "analytic"]
        },
        "band": { "type": "integer", "minimum": 1 },
        "vertical_datum": { "type": "string" },
        "analytic": {
          "type": "object",
          "additionalProperties": true,
          "description": "Parameters for analytic bathymetry (e.g. Thacker bowl)."
        }
      },
      "anyOf": [
        { "required": ["path"] },
        {
          "properties": { "kind": { "const": "analytic" } },
          "required": ["kind", "analytic"]
        }
      ]
    },
    "mesh_ref": {
      "type": "object",
      "additionalProperties": false,
      "required": ["path", "format"],
      "properties": {
        "path": { "type": "string", "minLength": 1 },
        "format": {
          "type": "string",
          "enum": ["ugrid", "gmsh", "2dm", "vtk", "other"]
        },
        "sha256": {
          "type": "string",
          "pattern": "^[a-fA-F0-9]{64}$"
        },
        "cell_type": {
          "type": "string",
          "enum": ["triangle", "quad", "mixed"]
        }
      }
    },
    "roughness": {
      "type": "object",
      "additionalProperties": false,
      "required": ["model"],
      "properties": {
        "model": {
          "type": "string",
          "enum": ["manning", "chezy", "nikuradse", "constant"]
        },
        "constant": { "type": "number", "minimum": 0 },
        "path": { "type": "string" },
        "sha256": {
          "type": "string",
          "pattern": "^[a-fA-F0-9]{64}$"
        },
        "zones": {
          "type": "array",
          "items": {
            "type": "object",
            "additionalProperties": false,
            "required": ["id", "value"],
            "properties": {
              "id": { "type": "string" },
              "value": { "type": "number", "minimum": 0 },
              "geometry_path": { "type": "string" }
            }
          }
        }
      }
    },
    "boundary_condition": {
      "type": "object",
      "additionalProperties": false,
      "required": ["id", "kind"],
      "properties": {
        "id": { "type": "string", "minLength": 1 },
        "kind": {
          "type": "string",
          "enum": [
            "wall",
            "open",
            "discharge",
            "stage",
            "rating_curve",
            "froude",
            "absorbing"
          ]
        },
        "edge_ids": {
          "type": "array",
          "items": { "type": "string" }
        },
        "polyline_path": { "type": "string" },
        "timeseries_path": { "type": "string" },
        "curve_id": { "type": "string" },
        "value": { "type": "number" },
        "attributes": {
          "type": "object",
          "additionalProperties": true
        }
      }
    }
  }
}