{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://buildchain.libkungfu.dev/schemas/release-train-transition-v1.schema.json",
  "title": "Buildchain Release Train Transition v1",
  "type": "object",
  "additionalProperties": false,
  "required": [
    "contract",
    "trainRoot",
    "expectedStateRoot",
    "from",
    "to",
    "event",
    "reason",
    "authorityRoots",
    "recordedAt",
    "requestRoot",
    "transitionRoot"
  ],
  "properties": {
    "contract": { "const": "kungfu-buildchain-release-train-transition/v1" },
    "trainRoot": { "$ref": "#/$defs/root" },
    "expectedStateRoot": { "$ref": "#/$defs/root" },
    "from": { "$ref": "#/$defs/state" },
    "to": { "$ref": "#/$defs/state" },
    "event": { "type": "string", "minLength": 1 },
    "reason": { "type": "string", "minLength": 1 },
    "authorityRoots": {
      "type": "array",
      "minItems": 1,
      "uniqueItems": true,
      "items": { "$ref": "#/$defs/root" }
    },
    "supersessionCause": { "$ref": "#/$defs/supersessionCause" },
    "replacementCutRoot": { "$ref": "#/$defs/root" },
    "replacementCandidateSha": { "$ref": "#/$defs/gitSha" },
    "recordedAt": { "type": "string", "format": "date-time" },
    "requestRoot": { "$ref": "#/$defs/root" },
    "transitionRoot": { "$ref": "#/$defs/root" }
  },
  "allOf": [
    {
      "if": { "properties": { "to": { "const": "superseded" } } },
      "then": {
        "required": [
          "supersessionCause",
          "replacementCutRoot",
          "replacementCandidateSha"
        ]
      },
      "else": {
        "not": {
          "anyOf": [
            { "required": ["supersessionCause"] },
            { "required": ["replacementCutRoot"] },
            { "required": ["replacementCandidateSha"] }
          ]
        }
      }
    }
  ],
  "$defs": {
    "gitSha": { "type": "string", "pattern": "^[0-9a-f]{40}$" },
    "root": { "type": "string", "pattern": "^sha256:[0-9a-f]{64}$" },
    "state": {
      "enum": [
        "preparing",
        "building",
        "repair-required",
        "publication-blocked",
        "publishable",
        "superseded",
        "terminal"
      ]
    },
    "supersessionCause": {
      "enum": [
        "release-blocker-repair",
        "incompatible-semantics",
        "alpha-base-incompatibility",
        "invalid-authority",
        "severe-security"
      ]
    }
  }
}