#!/bin/sh
set -eu

[ "$#" -eq 1 ] || [ "$#" -eq 2 ] || {
    echo "usage: $0 COUNTER_INFO_JSON [OUTPUT_JSON]" >&2
    exit 2
}
input=$1
output=${2:-}

analyze() {
    jq '
      ([.counter_sets[].counters[]] | unique) as $names |
      def named($pattern): any($names[]; test($pattern; "i"));
      if .schema_version != 1 or .workload != "metal-counter-info" or
         .device.has_unified_memory != true or .device.gpu_families.apple9 != true or
         .device.max_threadgroup_memory_bytes < 32768 or
         (.sampling_points.stage_boundary | type) != "boolean" or
         (.sampling_points.dispatch_boundary | type) != "boolean" or
         (.counter_sets | type) != "array" or (.counter_sets | length) == 0 or
         any(.counter_sets[]; (.name | type) != "string" or
             (.counters | type) != "array" or any(.counters[]; type != "string"))
      then error("invalid target Metal counter inventory") else
        (named("timestamp")) as $timestamp |
        (named("occup|active.*thread|thread.*active")) as $occupancy |
        (named("bandwidth|bytes|memory.*read|memory.*write|read.*memory|write.*memory"))
          as $bandwidth |
        (named("limiter|stall")) as $limiter |
        {
          schema_version: 1,
          scope: "target-metal-counter-capability-analysis",
          device: .device,
          sampling_points: .sampling_points,
          counter_set_count: (.counter_sets | length),
          available_counter_names: $names,
          capabilities: {
            timestamp: $timestamp,
            occupancy: $occupancy,
            bandwidth: $bandwidth,
            limiter_or_stall: $limiter
          },
          instrumentation: {
            stage_timestamps_available:
              (.sampling_points.stage_boundary and $timestamp),
            dispatch_performance_counters_available:
              (.sampling_points.dispatch_boundary and
               ($occupancy or $bandwidth or $limiter)),
            selected: (
              if .sampling_points.dispatch_boundary and
                 ($occupancy or $bandwidth or $limiter)
              then "public-dispatch-counter-sampling"
              elif .sampling_points.stage_boundary and $timestamp
              then "stage-timestamps-plus-xcode-gpu-trace"
              else "xcode-gpu-trace-only" end),
            reason: (
              if .sampling_points.dispatch_boundary and
                 ($occupancy or $bandwidth or $limiter)
              then "target exposes public dispatch-boundary performance counters"
              elif .sampling_points.stage_boundary and $timestamp
              then "public API lacks required performance counters; retain exact stage timestamps and use Xcode for occupancy/bandwidth/limiter evidence"
              else "public counter sampling lacks both required performance counters and stage timestamps"
              end)
          }
        }
      end
    ' "$input"
}

if [ -n "$output" ]; then analyze > "$output"; else analyze; fi