{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://example.com/xpm/schema.json",
  "title": "xpm config schema",
  "type": "object",
  "properties": {
    "image": { "type": "object", "description": "Image properties.",
      "properties": {
        "path": { "type": "string", "description": "Path to an 8-bit uncompressed image." },
        "size": { "type": "array", "items": { "type": "integer" }, "description": "Voxel count in 3 dimensions.", "minItems": 3, "maxItems": 3 },
        "resolution": { "type": "number", "description": "Side length of a voxel, m." },
        
        "phase": { "type": "object",
          "properties": {
            "void": { "type": "integer", "description": "Value for void voxels, must be 0.", "minimum": 0, "maximum": 0 },
            "solid": { "type": "integer", "description": "Value for solid voxels." }            
          },
          
          "required": ["void", "solid"]
        }
      },

      "required": ["path", "size", "resolution", "phase"]
    },

    "macro": { "type": "object", "description": "Macroscopic network properties.",
      "properties": {
        "contact_angle": { "type": "number", "description": "Contact angle, deg.", "default": 0 },
        "trans_multiplier": { "type": "number", "description": "Transmissibility multiplier.", "default": 1 }
      }
    },

    "darcy": { "type": "array", "description": "Array of darcy properties per under-resolved image value.",
      "items": { "type": "object",
        "properties": {
          "value": { "type": "integer", "description": "Value of the underlying under-resolved phase.", "minimum": 0, "maximum": 255 },
          "poro": { "type": "number", "description": "Porosity, frac." },
          "perm": { "type": "number", "description": "Permeability, mD." },
          "cap_press": { "type": "array", "items": { "type": "array" }, "description": "Capillary pressure curves, Pa (one data table per flooding cycle).", "maxItems": 2 },
          "rel_perm": { "type": "array", "items": { "type": "array" }, "description": "Relative permeability curves (array of two data tables per flooding cycle).", "maxItems": 2 },
          "rgb": { "type": "array", "items": { "type": "integer", "minimum": 0, "maximum": 255 }, "description": "Color in RGB format.", "minItems": 3, "maxItems": 3 },
          "file": { "type": "string", "description": "Path to an external JSON file that contains relevant darcy properties. " }
        }
      }
    },

    "solver": { "type": "object", "description": "Linear solver properties.",
      "properties": {
        "cache": { "type": "object",  "description": "Caching of pressure solutions.",
          "properties": {
            "use": { "type": "boolean", "default": false },
            "save": { "type": "boolean", "default": false }
          }
        },
        "decomposition": { "type": "array", "items": { "type": "integer" }, "description": "Volume decomposition in 3 dimensions. MPI processor count is the product of 3 components.", "minItems": 3, "maxItems": 3 },
        "tolerance": {  "type": "number", "description": "The convergence tolerance.", "default": 1e-6 },
        "max_iterations": { "type": "integer", "description": "Maximum number of iterations.", "default": 100 },
        "print_level": { "type": "integer", "description": "Requests automatic printing of setup and solve information.\n0 : no printout\n1 : print setup information\n2 : print solve information\n3 : print both setup and solve information", "minimum": 0, "maximum": 3, "default": 0 },
        "aggressive_number_of_levels": { "type": "integer", "description": "Defines the number of levels of aggressive coarsening.", "default": 0 }
      },

      "required": ["decomposition"]
    },

    "report": { "type": "object", "description": "Reporting properties.",
      "properties": {
        "display": { "type": "string", "description": "Display property of the 3D view.",
          "enum": ["pressure", "saturation", "permeability", "phase", "velem", "decomposition"], "default": "saturation"
        },
        "invasion_percolation": { "type": "boolean", "description": "Simulate invasion percolation.", "default": false },
        "occupancy_images": { "type": "boolean", "description": "Write 3D image files for different occupancies.", "default": false },
        "capillary_pressure_sw_step": { "type": "number", "description": "Sw step in capillary pressure curves.", "default": 0.05 },
        "relative_permeability_sw_step": { "type": "number", "description": "Sw step in relative permeability curves.", "default": 0.075 }
      }
    }
  }
}