#!/usr/bin/env bash
# gdd-structure-check.sh — deterministic section-presence check for system GDDs.
#
# Replaces a full-document model read per GDD with ~2 lines of output that cannot
# hallucinate a missing section. This is the cheapest real win available: the
# model spends its budget judging content, not counting headings.
#
# REPORTS PRESENCE ONLY — IT DOES NOT JUDGE COMPLETENESS.
# Which sections are REQUIRED depends on the workflow tier and on what the system
# defines (/design-review Phase 2b: Player Fantasy and Tuning Knobs are advisory
# at `standard`; Formulas is required at `standard` whenever the system defines
# numeric rules -- rates, curves, thresholds, costs. The system's category is a
# hint, not the test). A `standard`-tier GDD missing Player Fantasy is
# COMPLETE, so an "N/8" score would actively misreport it. The caller applies the
# tier; this script only says what is on disk.
#
# Usage:
#   bash .claude/scripts/gdd-structure-check.sh                    # all system GDDs
#   bash .claude/scripts/gdd-structure-check.sh design/gdd/foo.md  # one GDD
#
# Output (per GDD; the ABSENT line is omitted when nothing is absent):
#   combat.md PRESENT: Overview,Player Fantasy,Detailed Rules,...
#   loot.md   PRESENT: Overview,Detailed Rules,Edge Cases
#   loot.md   ABSENT:  Player Fantasy,Formulas,Tuning Knobs

set -u

cd "$(dirname "$0")/../.." || { echo "gdd-structure-check: cannot reach repo root" >&2; exit 1; }

# Each MATCH entry is an ERE alternation of every accepted heading for one
# required section; LABEL is the canonical name reported to the caller.
#
# "Detailed Rules" is authored as "## Detailed Design" by the GDD template and by
# /design-system. They denote the SAME required section. Accepting only one name
# reports 7/8 MISSING on every conforming GDD — the exact failure this guard
# exists to prevent, and it is regression-tested.
MATCH=("Overview" \
       "Player Fantasy" \
       "Detailed (Rules|Design)" \
       "Formulas" \
       "Edge Cases" \
       "Dependencies" \
       "Tuning Knobs" \
       "Acceptance Criteria")
LABEL=("Overview" "Player Fantasy" "Detailed Rules" "Formulas" "Edge Cases" \
       "Dependencies" "Tuning Knobs" "Acceptance Criteria")

# Governance and registry docs that live in design/gdd/ but are not system GDDs.
not_a_system_gdd() {
    case "$(basename "$1")" in
        game-concept.md|systems-index.md|game-pillars.md|gdd-cross-review-*.md) return 0 ;;
        gameplay-tags.md|fixture-swap-ledger.md|entity-registry.md)             return 0 ;;
        *) return 1 ;;
    esac
}

check_file() {
    local f="$1" present="" absent="" i s
    for i in "${!MATCH[@]}"; do
        s="${MATCH[$i]}"
        # [[:space:]] not [ \t] — inside double quotes the shell leaves \t literal
        # and ERE reads the class as {space, backslash, t}, so real tabs fail to
        # match while "##tOverview" false-positives.
        if grep -qiE "^##+[[:space:]]+([0-9]+[.)]?[[:space:]]*)?${s}" "$f"; then
            present="$present,${LABEL[$i]}"
        else
            absent="$absent,${LABEL[$i]}"
        fi
    done
    local b; b="$(basename "$f")"
    echo "$b PRESENT: ${present#,}"
    [ -n "$absent" ] && echo "$b ABSENT:  ${absent#,}"
    return 0
}

if [ $# -gt 0 ] && [ -n "${1:-}" ]; then
    [ -f "$1" ] || { echo "Not found: $1" >&2; exit 1; }
    check_file "$1"
    exit 0
fi

any=0
# -maxdepth 1 keeps design/gdd/reviews/ out of scope — /design-review writes its
# own output there, and sweeping it in makes the tool review its own reports.
while IFS= read -r f; do
    [ -n "$f" ] || continue
    not_a_system_gdd "$f" && continue
    any=1
    check_file "$f"
done <<EOF
$(find design/gdd -maxdepth 1 -name '*.md' -type f 2>/dev/null | sort)
EOF

[ "$any" -eq 1 ] || echo "No system GDDs found in design/gdd/."