{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://ayagmar.github.io/llm-usage-metrics/report-compare.v1.schema.json",
  "title": "llm-usage-metrics compare report output (v1)",
  "description": "Envelope and payload for compare report --json output. Diagnostics are excluded by contract.",
  "allOf": [
    {
      "$ref": "https://ayagmar.github.io/llm-usage-metrics/report-common.v1.schema.json#/$defs/envelope"
    }
  ],
  "properties": {
    "report": { "const": "compare" },
    "data": {
      "description": "Compare payload: both windows plus metric and source deltas.",
      "type": "object",
      "properties": {
        "current": { "$ref": "#/$defs/windowSummary" },
        "baseline": { "$ref": "#/$defs/windowSummary" },
        "totals": {
          "description": "Per-metric comparison rows.",
          "type": "array",
          "items": { "$ref": "#/$defs/metricRow" }
        },
        "sources": {
          "description": "Per-source cost comparison rows.",
          "type": "array",
          "items": { "$ref": "#/$defs/sourceRow" }
        }
      },
      "required": ["current", "baseline", "totals", "sources"],
      "additionalProperties": false
    }
  },
  "$defs": {
    "windowRange": {
      "description": "A compared date window.",
      "type": "object",
      "properties": {
        "since": { "description": "Window start (YYYY-MM-DD).", "type": "string" },
        "until": { "description": "Window end (YYYY-MM-DD).", "type": "string" },
        "label": { "description": "Human-readable window label.", "type": "string" }
      },
      "required": ["since", "until", "label"],
      "additionalProperties": false
    },
    "windowTotals": {
      "description": "Usage totals for one window (non-negative).",
      "allOf": [
        {
          "$ref": "https://ayagmar.github.io/llm-usage-metrics/report-common.v1.schema.json#/$defs/usageTotals"
        }
      ],
      "properties": {
        "events": { "description": "Events in the window.", "type": "integer", "minimum": 0 },
        "activeDays": {
          "description": "Days with at least one event in the window.",
          "type": "integer",
          "minimum": 0
        }
      },
      "required": ["events", "activeDays"],
      "unevaluatedProperties": false
    },
    "windowTotalsDelta": {
      "description": "Current-minus-baseline totals; values can be negative.",
      "type": "object",
      "properties": {
        "inputTokens": { "description": "Input token delta.", "type": "integer" },
        "outputTokens": { "description": "Output token delta.", "type": "integer" },
        "reasoningTokens": { "description": "Reasoning token delta.", "type": "integer" },
        "cacheReadTokens": { "description": "Cache-read token delta.", "type": "integer" },
        "cacheWriteTokens": { "description": "Cache-write token delta.", "type": "integer" },
        "totalTokens": { "description": "Total token delta.", "type": "integer" },
        "costUsd": { "description": "Cost delta in USD.", "type": "number" },
        "costIncomplete": {
          "description": "True when either side's cost is missing pricing.",
          "type": "boolean"
        },
        "events": { "description": "Event count delta.", "type": "integer" },
        "activeDays": { "description": "Active day delta.", "type": "integer" }
      },
      "required": [
        "inputTokens",
        "outputTokens",
        "reasoningTokens",
        "cacheReadTokens",
        "cacheWriteTokens",
        "totalTokens",
        "events",
        "activeDays"
      ],
      "additionalProperties": false
    },
    "windowSummary": {
      "description": "One compared window with its totals.",
      "type": "object",
      "properties": {
        "window": { "$ref": "#/$defs/windowRange" },
        "totals": { "$ref": "#/$defs/windowTotals" }
      },
      "required": ["window", "totals"],
      "additionalProperties": false
    },
    "metricRow": {
      "description": "One compared metric with values and deltas; unresolved values are omitted.",
      "type": "object",
      "properties": {
        "key": {
          "description": "Metric key.",
          "type": "string",
          "enum": [
            "inputTokens",
            "outputTokens",
            "reasoningTokens",
            "cacheReadTokens",
            "cacheWriteTokens",
            "totalTokens",
            "costUsd",
            "events",
            "activeDays"
          ]
        },
        "label": { "description": "Display label for the metric.", "type": "string" },
        "valueType": {
          "description": "Render hint: integer or USD.",
          "type": "string",
          "enum": ["integer", "usd"]
        },
        "current": { "description": "Current-window value.", "type": "number" },
        "baseline": { "description": "Baseline-window value.", "type": "number" },
        "delta": { "description": "current minus baseline; can be negative.", "type": "number" },
        "deltaRatio": {
          "description": "delta / baseline as a 0-centered fraction; can be negative.",
          "type": "number"
        },
        "currentCostIncomplete": {
          "description": "True when the current cost is missing pricing.",
          "type": "boolean"
        },
        "baselineCostIncomplete": {
          "description": "True when the baseline cost is missing pricing.",
          "type": "boolean"
        },
        "deltaCostIncomplete": {
          "description": "True when the cost delta involves missing pricing.",
          "type": "boolean"
        }
      },
      "required": ["key", "label", "valueType"],
      "additionalProperties": false
    },
    "sourceRow": {
      "description": "One source's window totals and deltas.",
      "type": "object",
      "properties": {
        "source": { "description": "Source id.", "type": "string" },
        "current": { "$ref": "#/$defs/windowTotals" },
        "baseline": { "$ref": "#/$defs/windowTotals" },
        "delta": { "$ref": "#/$defs/windowTotalsDelta" },
        "deltaRatio": {
          "description": "Per-metric delta fractions keyed by metric name; unresolved entries omitted.",
          "type": "object",
          "propertyNames": {
            "enum": [
              "inputTokens",
              "outputTokens",
              "reasoningTokens",
              "cacheReadTokens",
              "cacheWriteTokens",
              "totalTokens",
              "costUsd",
              "events",
              "activeDays"
            ]
          },
          "additionalProperties": { "type": "number" }
        }
      },
      "required": ["source", "current", "baseline", "delta", "deltaRatio"],
      "additionalProperties": false
    }
  }
}