#!/usr/bin/env bash
# Requires bash ≥ 4 for `mapfile`; on macOS install via `brew install bash`
# and invoke as `bash scripts/quality/license-headers.sh`.  The portable
# fallback below works on bash 3.2 too.
# scripts/quality/license-headers.sh
#
# Verify that every source file under code/ carries an SPDX-License-
# Identifier header.  The project policy (doc/release-policy.md) is:
#
#   * Every conformallab++ source file (.h, .hpp, .cpp under code/include
#     or code/src, but NOT code/deps/) must have:
#       SPDX-License-Identifier: MIT
#   * The copyright line is encouraged but not enforced (the year is
#     allowed to lag).
#
# Files under code/deps/ are vendored third-party code (Eigen, JSON,
# GLFW, libigl, …) and are skipped — they carry their own licenses.
#
# Exit codes:
#   0  every checked file has the SPDX header
#   1  at least one file is missing it
#   2  prerequisite missing
#
# Run from any directory; the script resolves the repo root from its own path.

set -euo pipefail
ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
cd "$ROOT"

SPDX="SPDX-License-Identifier: MIT"

# Files to check: code/include + code/src + code/tests.  Skip code/deps.
FILES_LIST="$(find code/include code/src code/tests \
    \( -name "*.h" -o -name "*.hpp" -o -name "*.cpp" \) \
    -type f 2>/dev/null \
    | grep -v "^code/deps/" \
    | grep -v " 2\." \
    | sort)"

n_total=0
n_missing=0
missing_list=""
while IFS= read -r f; do
    [ -z "$f" ] && continue
    n_total=$((n_total + 1))
    # Check only the first 30 lines — SPDX must be near the top.
    if ! head -30 "$f" | grep -q "$SPDX"; then
        n_missing=$((n_missing + 1))
        missing_list="$missing_list  $f
"
    fi
done <<EOF
$FILES_LIST
EOF

if [ "$n_total" -eq 0 ]; then
    echo "FAIL: no source files found under code/{include,src,tests}/" >&2
    exit 2
fi

echo "Checked $n_total source files for SPDX header."

if [ "$n_missing" -gt 0 ]; then
    echo
    echo "FAIL: $n_missing file(s) missing '$SPDX' in their first 30 lines:"
    printf '%s' "$missing_list"
    echo
    echo "Recovery: add this two-line header at the top of each file:"
    echo "  // Copyright (c) 2024-$(date +%Y) Tarik Moussa."
    echo "  // $SPDX"
    exit 1
fi

echo "OK: every checked file carries '$SPDX'."
exit 0