#!/usr/bin/env bash
set -euo pipefail

ROOT="$(cd "$(dirname "$0")/.." && pwd)"
HOTGRAPH="$ROOT/hotgraph/source_hotgraph.json"
USECASES="$ROOT/configs/usecase_registry.json"
USECASE="${1:-migration_brief}"
GOAL_OVERRIDE="${2:-}"

RUN_DIR="$ROOT/runs/run-$(date -u +"%Y%m%dT%H%M%SZ")"
PACKET="$RUN_DIR/control_packet.json"
BRIEF="$RUN_DIR/brief.md"

mkdir -p "$RUN_DIR"

USECASE_JSON="$(jq -c --arg usecase "$USECASE" '.usecases[] | select(.id == $usecase)' "$USECASES")"
if [ -z "$USECASE_JSON" ]; then
  echo "unknown usecase: $USECASE" >&2
  exit 1
fi

if [ -n "$GOAL_OVERRIDE" ]; then
  GOAL="$GOAL_OVERRIDE"
else
  GOAL="$(printf '%s' "$USECASE_JSON" | jq -r '.goal_template')"
fi

score_row() {
  local row_json="$1"
  local usecase_id role priority package_count score text
  usecase_id="$(printf '%s' "$USECASE_JSON" | jq -r '.id')"
  role="$(printf '%s' "$row_json" | jq -r '.role')"
  priority="$(printf '%s' "$row_json" | jq -r '.priority')"
  package_count="$(printf '%s' "$row_json" | jq -r '.package_count')"
  score=0

  if [ "$priority" = "high" ]; then
    score=$((score + 2))
  fi
  if [ "$package_count" -gt 4 ]; then
    package_count=4
  fi
  score=$((score + package_count))

  case "$usecase_id:$role" in
    migration_brief:successor_branch) score=$((score + 5)) ;;
    migration_brief:kernel_candidate|migration_brief:control_plane_candidate) score=$((score + 4)) ;;
    migration_brief:product_runtime_reference) score=$((score + 3)) ;;
    migration_brief:live_shell|migration_brief:memory_substrate|migration_brief:manifest_executor) score=$((score + 2)) ;;
    control_scorecard:control_plane_candidate) score=$((score + 5)) ;;
    control_scorecard:memory_substrate) score=$((score + 4)) ;;
    control_scorecard:live_shell|control_scorecard:successor_branch|control_scorecard:product_runtime_reference) score=$((score + 3)) ;;
    control_scorecard:kernel_candidate|control_scorecard:manifest_executor) score=$((score + 2)) ;;
    runtime_split:successor_branch|runtime_split:kernel_candidate) score=$((score + 5)) ;;
    runtime_split:product_runtime_reference|runtime_split:control_plane_candidate) score=$((score + 4)) ;;
    runtime_split:manifest_executor) score=$((score + 3)) ;;
    runtime_split:live_shell|runtime_split:memory_substrate) score=$((score + 2)) ;;
    product_quickstart:product_runtime_reference) score=$((score + 5)) ;;
    product_quickstart:live_shell) score=$((score + 4)) ;;
    product_quickstart:successor_branch|product_quickstart:control_plane_candidate) score=$((score + 3)) ;;
    product_quickstart:manifest_executor) score=$((score + 2)) ;;
    product_quickstart:kernel_candidate|product_quickstart:memory_substrate) score=$((score + 1)) ;;
  esac

  text="$(printf '%s' "$GOAL" | tr '[:upper:]' '[:lower:]')"
  case "$text:$role" in
    *kernel*:kernel_candidate) score=$((score + 3)) ;;
  esac
  case "$text:$role" in
    *control*:control_plane_candidate) score=$((score + 3)) ;;
  esac
  case "$text:$role" in
    *product*:product_runtime_reference) score=$((score + 3)) ;;
  esac
  case "$text:$role" in
    *live*:live_shell) score=$((score + 2)) ;;
  esac

  printf '%s' "$score"
}

RANKED_TMP="$(mktemp)"
trap 'rm -f "$RANKED_TMP"' EXIT

jq -c '.summary[]' "$HOTGRAPH" | while IFS= read -r row; do
  score="$(score_row "$row")"
  jq -n --argjson score "$score" --argjson row "$row" '$row + {score:$score}' >> "$RANKED_TMP"
done

RANKED_JSON="$(jq -s 'sort_by(.score, .priority == "high", .package_count, .id) | reverse' "$RANKED_TMP")"
RECOMMENDED_HOME="$(printf '%s' "$RANKED_JSON" | jq -r '.[0].id')"
TOP_ROLE="$(printf '%s' "$RANKED_JSON" | jq -r '.[0].role')"

FRONTIER_READ="top_ranked_source_selected"
case "$USECASE:$TOP_ROLE" in
  migration_brief:successor_branch) FRONTIER_READ="favor_successor_branch_over_live_shell" ;;
  control_scorecard:control_plane_candidate) FRONTIER_READ="favor_control_plane_for_metrics_logic" ;;
  product_quickstart:product_runtime_reference) FRONTIER_READ="favor_thin_product_runtime" ;;
  runtime_split:kernel_candidate) FRONTIER_READ="favor_kernel_extraction" ;;
esac

ONE_LINER="Use \`$RECOMMENDED_HOME\` as the recommended home."
case "$USECASE" in
  migration_brief) ONE_LINER="Use \`$RECOMMENDED_HOME\` as the forward home for new runtime-shaping work." ;;
  control_scorecard) ONE_LINER="Use \`$RECOMMENDED_HOME\` as the policy and scorecard home, with the hotgraph as intake." ;;
  runtime_split) ONE_LINER="Split shell, kernel, and memory roles around \`$RECOMMENDED_HOME\` first." ;;
  product_quickstart) ONE_LINER="Use \`$RECOMMENDED_HOME\` as the reference for the smallest user-facing runtime slice." ;;
esac

RISKS='[]'
case "$RECOMMENDED_HOME" in
  nix_codecli) RISKS='["live shell may absorb more product logic than it should"]' ;;
  tmp_meta3_engine_test) RISKS='["successor branch is richer but less settled than the live shell"]' ;;
  meta3_graph_core) RISKS='["kernel candidate is too low-level to be the whole product by itself"]' ;;
esac
if [ "$USECASE" = "control_scorecard" ]; then
  RISKS="$(printf '%s' "$RISKS" | jq '. + ["metrics may drift if the hotgraph source registry is not refreshed"]')"
fi

printf '%s' "$RANKED_JSON" | jq -n \
  --arg generated_at "$(date -u +"%Y-%m-%dT%H:%M:%SZ")" \
  --arg goal "$GOAL" \
  --arg usecase_id "$USECASE" \
  --arg hotgraph_ref "$HOTGRAPH" \
  --arg target_artifact "$(printf '%s' "$USECASE_JSON" | jq -r '.target_artifact')" \
  --arg one_liner "$ONE_LINER" \
  --arg frontier_read "$FRONTIER_READ" \
  --arg recommended_home "$RECOMMENDED_HOME" \
  --argjson ranked "$RANKED_JSON" \
  --argjson risks "$RISKS" \
  '{
    generated_at:$generated_at,
    goal:$goal,
    usecase_id:$usecase_id,
    source_ids:($ranked | map(.id)),
    hotgraph_ref:$hotgraph_ref,
    target_artifact:$target_artifact,
    decision:{
      one_liner:$one_liner,
      frontier_read:$frontier_read,
      recommended_home:$recommended_home,
      recommended_sources:($ranked | map(.id)[:4]),
      risks:$risks
    }
  }' > "$PACKET"

{
  echo "# Control Brief"
  echo
  echo "Goal: \`$(jq -r '.goal' "$PACKET")\`"
  echo
  echo "Use case: \`$(jq -r '.usecase_id' "$PACKET")\`"
  echo
  echo "Clean product one-liner: $(jq -r '.decision.one_liner' "$PACKET")"
  echo
  echo "Pareto read: \`$(jq -r '.decision.frontier_read' "$PACKET")\`"
  echo
  echo "Recommended home: \`$(jq -r '.decision.recommended_home' "$PACKET")\`"
  echo
  echo "## Source order"
  echo
  jq -r '.decision.recommended_sources[] | "- `\(.)`"' "$PACKET"
  if [ "$(jq '.decision.risks | length' "$PACKET")" -gt 0 ]; then
    echo
    echo "## Risks"
    echo
    jq -r '.decision.risks[] | "- \(.)"' "$PACKET"
  fi
} > "$BRIEF"

printf '%s\n' "$PACKET"
printf '%s\n' "$BRIEF"