{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://acdl.cloudinit.dev/schemas/ir.schema.json",
  "title": "ACDL Target Stack IR",
  "description": "Substrate-neutral description of a target stack: resources with typed inputs/outputs/NFRs, relationships (single parent per child), composition tree (max depth 5), and policy hooks. The L1 registry, L2 thin-composition tree, contract YML, and PolicyCheckResult schema are all defined against this IR. Substrate adapters (the Terraform adapter in v1) are the only substrate-specific code.",
  "$comment": "v1 ships one adapter (Terraform). The IR is nearly isomorphic to Terraform in v1 (ARCHITECTURE.md §12.1); the adapter compiles resource.module -> module block, resource.inputs -> variable + arg, resource.outputs -> output, relationship.kind=uses_output -> interpolation, relationship.kind=parent -> composition ordering hint. As more adapters appear (v2+), the IR gains expressiveness; the L1 content + contract YML + thin-composition tree do not change. The schema body is substrate-agnostic: no Terraform block keywords (variable/output/resource as blocks) and no aws_ provider prefixes in the schema keywords; type values are IR types (aws:s3:bucket), not Terraform resource types (aws_s3_bucket).",
  "type": "object",
  "required": ["version", "stack", "resources"],
  "properties": {
    "version": {
      "type": "string",
      "description": "IR schema version (semver).",
      "pattern": "^\\d+\\.\\d+\\.\\d+$"
    },
    "stack": {
      "type": "object",
      "description": "The L1/L2 stack identity this IR represents.",
      "required": ["name", "kind", "depth"],
      "properties": {
        "name": {
          "type": "string",
          "pattern": "^l[12]-[a-z][a-z0-9-]*$",
          "description": "Stack name matching the L1/L2 folder name."
        },
        "kind": {
          "type": "string",
          "enum": ["l1", "l2"],
          "description": "l1 = primitive; l2 = thin-composition."
        },
        "depth": {
          "type": "integer",
          "minimum": 1,
          "maximum": 5,
          "description": "Composition depth (ARCHITECTURE.md §3: max depth 5). L2->L1 is depth 1."
        }
      }
    },
    "resources": {
      "type": "array",
      "minItems": 1,
      "items": {"$ref": "#/$defs/resource"}
    },
    "relationships": {
      "type": "array",
      "description": "Optional in v1; present when the adapter needs explicit ordering/output wiring hints beyond parent composition.",
      "items": {"$ref": "#/$defs/relationship"}
    }
  },
  "$defs": {
    "resource": {
      "type": "object",
      "required": ["id", "type", "module", "inputs"],
      "properties": {
        "id": {
          "type": "string",
          "pattern": "^[a-z][a-z0-9-]*$",
          "description": "Local IR resource id (unique within the stack)."
        },
        "type": {
          "type": "string",
          "description": "IR-typed resource identifier (substrate-agnostic), e.g. 'aws:s3:bucket'. NOT a Terraform resource type ('aws_s3_bucket'); the adapter translates IR type -> substrate type."
        },
        "module": {
          "type": "string",
          "pattern": "^l1-[a-z][a-z0-9-]*@\\d+\\.\\d+\\.\\d+$",
          "description": "L1 registry reference: name@semver (W3.D). MAJOR bumps require a new registry entry (immutable publication); old entry enters a 12-month deprecation window."
        },
        "parent": {
          "type": "string",
          "description": "Parent resource id. Absent for the root. Single parent per child (ARCHITECTURE.md §12.1)."
        },
        "inputs": {
          "type": "object",
          "description": "Input values keyed by the L1 module's declared inputs. Free-form in v1 (validated at contract->IR resolution against the L1 registry); typed per-L1 in v1.2.",
          "additionalProperties": {"type": ["string", "number", "boolean"]}
        },
        "outputs": {
          "type": "object",
          "description": "Typed output contract. The adapter translates this to a substrate output block (e.g. Terraform output).",
          "additionalProperties": {"$ref": "#/$defs/outputSpec"}
        },
        "nfrs": {
          "type": "object",
          "description": "Declared non-functional requirements (latency, throughput, error rate). Opaque to the adapter; consumed by the confidence signal's NFR input.",
          "additionalProperties": true
        }
      }
    },
    "outputSpec": {
      "type": "object",
      "required": ["type"],
      "properties": {
        "type": {
          "type": "string",
          "description": "IR-typed output type: a primitive ('string', 'arn') or a reference ('ref:<resourceId>.<outputName>')."
        },
        "description": {"type": "string"}
      }
    },
    "relationship": {
      "type": "object",
      "required": ["from", "to", "kind"],
      "properties": {
        "from": {"type": "string", "description": "Source resource id."},
        "to": {"type": "string", "description": "Target resource id."},
        "kind": {
          "type": "string",
          "enum": ["parent", "depends_on", "uses_output"],
          "description": "v1 uses 'parent' (composition ordering) + 'uses_output' (interpolation). 'depends_on' is reserved for v2 explicit-dependency cases."
        },
        "shared_keyword": {
          "type": "string",
          "description": "Reserved for v2 multi-relationship dependencies. Unused in v1."
        }
      }
    }
  }
}