#!/usr/bin/env bash
# Regression test for the `skill-frontmatter` pre-commit hook.
#
# The hook is `entry: bash` with `args: ['-c', <script>, <arg0>]`, and this file
# drives that exact call shape -- read out of .pre-commit-config.yaml, never
# re-implemented here. That is the whole point. `grep -rn skill-frontmatter
# tests/` returned nothing before this file existed, and the two defect classes
# below are both invisible to a test that copies the script body and calls it
# some other way:
#
#   1. THE POSITIONAL DROP. `bash -c <script> fileA fileB` puts fileA in $0, not
#      in "$@". The hook had no arg0 placeholder, so pre-commit's FIRST filename
#      was swallowed -- and a single-file commit, the normal case, ran the loop
#      body zero times and reported Passed having checked nothing. A test that
#      sources or inlines the script never sees this; only the real invocation
#      shape does. Cases 2 and 3 below are that regression.
#
#   2. THE UNSCOPED GREP. The checks used to run over the WHOLE file, and the
#      version check was `grep -A10 "^metadata:" | grep -q "  version:"`. Four
#      confirmed ways to pass while measuring nothing, all pinned below:
#        * `metadata:` in a BODY code fence satisfies it (skill-author's own
#          docs quote exactly such a block);
#        * `-A10` runs past the end of the metadata block, so a `version:`
#          belonging to a following `source:` list entry satisfies it
#          (write-docs and research both have `source:` right after `metadata:`);
#        * `"  version:"` is an unanchored substring, so `    version:` at a
#          deeper nesting satisfies it;
#        * and the mirror image, a false NEGATIVE: a metadata block with more
#          than 10 lines before `version:` was reported missing.
#
# Plus the semver assertion, which is not redundant with presence: write-docs
# carried `version: "1.0"` -- present, well-nested, and not a version -- through
# an entire PR under a check that only ever asked whether the key was there.
set -euo pipefail

REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
CONFIG="$REPO_ROOT/.pre-commit-config.yaml"
PASS=0
FAIL=0

pass() { echo "  PASS: $1"; PASS=$((PASS + 1)); }
fail() { echo "  FAIL: $1"; FAIL=$((FAIL + 1)); }

# Same guard shape as tests/test-check-executables-allow-sync.sh: the hook
# definition is YAML and reading it any other way is guessing. README.md lists
# python3/PyYAML as a pre-push prerequisite, and `run-tests.sh --strict` turns
# this skip into a failure, which is the correct reading when it runs as a gate.
command -v python3 > /dev/null 2>&1 || { echo "SKIP: python3 is required to read the hook definition out of .pre-commit-config.yaml"; exit 77; }
python3 -c 'import yaml' > /dev/null 2>&1 || { echo "SKIP: PyYAML is required to read the hook definition out of .pre-commit-config.yaml"; exit 77; }

TMPDIR_T="$(mktemp -d)"
trap 'rm -rf "$TMPDIR_T"' EXIT

# ---------------------------------------------------------------------------
# The hook, as pre-commit will run it
# ---------------------------------------------------------------------------
# ENTRY and ARGS come straight out of the config. run_hook() then reproduces
# pre-commit's own composition -- entry, then args, then the filenames appended
# LAST -- so the positional handling under test is the real one.
HOOK_JSON="$TMPDIR_T/hook.json"
python3 - "$CONFIG" "$HOOK_JSON" <<'PY'
import json
import sys

import yaml

config_path, out_path = sys.argv[1:3]
with open(config_path, encoding='utf-8') as fh:
    cfg = yaml.safe_load(fh) or {}

found = None
for repo in cfg.get('repos') or []:
    for hook in repo.get('hooks') or []:
        if hook.get('id') == 'skill-frontmatter':
            found = hook

if found is None:
    sys.exit("skill-frontmatter hook not found in " + config_path)

with open(out_path, 'w', encoding='utf-8') as fh:
    json.dump(
        {
            'entry': found.get('entry'),
            'args': found.get('args') or [],
            'files': found.get('files'),
            'pass_filenames': found.get('pass_filenames', True),
            'always_run': found.get('always_run', False),
        },
        fh,
    )
PY

# Reads NUL-delimited fields on stdin into the named array. bash 3.2 (macOS) has
# no `mapfil[e]`/`readarra[y]` builtin, and tests/test-vale-wrap.sh's static scan
# rejects both — the bracket classes above match what a bare spelling would while
# keeping one out of this file, the same trick that file uses for `npro[c]`.
read_nul_array() {
  local __var="$1"
  shift
  local __item
  eval "$__var=()"
  while IFS= read -r -d '' __item; do
    eval "$__var+=(\"\$__item\")"
  done
}

ENTRY="$(python3 -c 'import json,sys; print(json.load(open(sys.argv[1]))["entry"])' "$HOOK_JSON")"
ARGS=()
read_nul_array ARGS < <(python3 -c '
import json
import sys

data = json.load(open(sys.argv[1]))
for arg in data["args"]:
    sys.stdout.write(arg + "\0")
' "$HOOK_JSON")

RUN_OUT=""
RUN_RC=0
# run_hook <file>... -- exactly `entry args... files...`, pre-commit's ordering.
run_hook() {
  RUN_RC=0
  RUN_OUT="$("$ENTRY" ${ARGS[@]+"${ARGS[@]}"} "$@" 2>&1)" || RUN_RC=$?
}

# write_skill <path> <frontmatter-body> [markdown-body]
write_skill() {
  local path="$1" frontmatter="$2" body="${3:-# Heading

Body text.}"
  mkdir -p "$(dirname "$path")"
  {
    printf -- '---\n'
    printf '%s\n' "$frontmatter"
    printf -- '---\n\n'
    printf '%s\n' "$body"
  } > "$path"
}

VALID_FM='name: valid-skill
description: A skill whose frontmatter is complete and well formed.
metadata:
  version: "1.0.0"'

assert_passes() { # <label> <file>...
  local label="$1"
  shift
  run_hook "$@"
  if [[ $RUN_RC -eq 0 ]]; then
    pass "$label"
  else
    fail "$label -- expected exit 0, got $RUN_RC. Output: $RUN_OUT"
  fi
}

assert_fails_with() { # <label> <needle> <file>...
  local label="$1" needle="$2"
  shift 2
  run_hook "$@"
  if [[ $RUN_RC -eq 0 ]]; then
    fail "$label -- exited 0, so the hook reported Passed having checked nothing. Output: $RUN_OUT"
  elif [[ "$RUN_OUT" != *"$needle"* ]]; then
    fail "$label -- exited $RUN_RC but the message lacked '$needle'. Output: $RUN_OUT"
  else
    pass "$label"
  fi
}

# ---------------------------------------------------------------------------
# 1. The call shape itself
# ---------------------------------------------------------------------------
# Asserted as a contract as well as behaviourally, because the behavioural
# symptom of losing arg0 is a GREEN run -- the least likely thing to be noticed.
echo "--- the hook passes an arg0 placeholder so pre-commit's filenames land in \"\$@\" ---"
if [[ "$ENTRY" != "bash" ]]; then
  fail "entry is '$ENTRY', not bash -- the arg0 reasoning below assumes bash -c"
elif [[ ${#ARGS[@]} -lt 3 ]]; then
  fail "args has ${#ARGS[@]} entries; a 'bash -c <script>' hook needs a third, the arg0 placeholder, or the first filename is dropped from \"\$@\""
elif [[ "${ARGS[0]}" != "-c" ]]; then
  fail "args[0] is '${ARGS[0]}', not -c"
elif [[ "${ARGS[2]}" == -* ]]; then
  fail "args[2] is '${ARGS[2]}', which bash will read as a flag rather than as \$0"
else
  pass "args is [-c, <script>, '${ARGS[2]}'] -- the third entry becomes \$0 and every filename reaches \"\$@\""
fi

FILES_PATTERN="$(python3 -c 'import json,sys; print(json.load(open(sys.argv[1]))["files"] or "")' "$HOOK_JSON")"
PASS_FILENAMES="$(python3 -c 'import json,sys; print(json.load(open(sys.argv[1]))["pass_filenames"])' "$HOOK_JSON")"
echo ""
echo "--- the hook is filename-driven, so the loop is the only thing that ever runs ---"
if [[ "$PASS_FILENAMES" != "True" ]]; then
  fail "pass_filenames is $PASS_FILENAMES; with no filenames the loop body never executes and the hook is a permanent no-op"
elif [[ "$FILES_PATTERN" != '^plugins/[^/]+/\.apm/skills/[^/]+/SKILL\.md$' ]]; then
  fail "files: is '$FILES_PATTERN', not the .apm/ skill scope -- ADR-0020's gates and this one must agree on scope"
else
  pass "pass_filenames is on and files: is the .apm/ skill scope"
fi

# ---------------------------------------------------------------------------
# 2. A single bad file, on its own -- THE regression
# ---------------------------------------------------------------------------
# This is the shipped bug in one line: one file, which is what a commit
# touching one skill hands the hook. Before the arg0 fix the file landed in $0,
# "$@" was empty, and this exited 0.
echo ""
echo "--- a SINGLE bad file fails (before the arg0 fix this exited 0 having read nothing) ---"
write_skill "$TMPDIR_T/single/SKILL.md" 'name: single
description: Missing its metadata block entirely.'
assert_fails_with "one file with no metadata block is rejected" "missing required frontmatter fields" "$TMPDIR_T/single/SKILL.md"

echo ""
echo "--- and a single GOOD file still passes, so the case above is not failing for some other reason ---"
write_skill "$TMPDIR_T/single-ok/SKILL.md" "$VALID_FM"
assert_passes "one valid file passes" "$TMPDIR_T/single-ok/SKILL.md"

# ---------------------------------------------------------------------------
# 3. Position within the argument list must not matter
# ---------------------------------------------------------------------------
echo ""
echo "--- the bad file is caught wherever it sits in the argument list ---"
write_skill "$TMPDIR_T/ok-a/SKILL.md" "$VALID_FM"
write_skill "$TMPDIR_T/ok-b/SKILL.md" "$VALID_FM"
write_skill "$TMPDIR_T/bad/SKILL.md" 'name: bad
description: No metadata block.'

assert_fails_with "bad file FIRST is caught" "$TMPDIR_T/bad/SKILL.md" \
  "$TMPDIR_T/bad/SKILL.md" "$TMPDIR_T/ok-a/SKILL.md" "$TMPDIR_T/ok-b/SKILL.md"
assert_fails_with "bad file LAST is caught (the loop reaches the end of \"\$@\")" "$TMPDIR_T/bad/SKILL.md" \
  "$TMPDIR_T/ok-a/SKILL.md" "$TMPDIR_T/ok-b/SKILL.md" "$TMPDIR_T/bad/SKILL.md"
assert_passes "three valid files pass" "$TMPDIR_T/ok-a/SKILL.md" "$TMPDIR_T/ok-b/SKILL.md" "$TMPDIR_T/single-ok/SKILL.md"

# ---------------------------------------------------------------------------
# 4. The four grep defects
# ---------------------------------------------------------------------------
echo ""
echo "--- defect 1: a \`metadata:\` block in a BODY code fence is documentation, not frontmatter ---"
# skill-author's docs quote a metadata block verbatim. Under the old whole-file
# grep that quotation satisfied the check for the file quoting it.
write_skill "$TMPDIR_T/fence/SKILL.md" 'name: fence
description: Frontmatter has no metadata block; the body quotes one.' '# Fence

Skills declare their version like this:

```yaml
metadata:
  version: "1.0.0"
```'
assert_fails_with "a quoted metadata block in the body does not satisfy metadata.version" "missing required frontmatter fields" "$TMPDIR_T/fence/SKILL.md"

echo ""
echo "--- ... and the same for name: and description: quoted in the body ---"
write_skill "$TMPDIR_T/fence-keys/SKILL.md" 'metadata:
  version: "1.0.0"' '# Fence keys

```yaml
name: not-the-real-name
description: not the real description
```'
assert_fails_with "body-fenced name:/description: do not satisfy the presence checks" "name: description:" "$TMPDIR_T/fence-keys/SKILL.md"

echo ""
echo "--- defect 2: a \`version:\` under a following \`source:\` list is not metadata.version ---"
# `-A10` ran ten lines past `metadata:` regardless of where the block ended.
# write-docs and research both carry a `source:` list immediately after it.
write_skill "$TMPDIR_T/source-list/SKILL.md" 'name: source-list
description: metadata has no version; the next top-level key does.
metadata:
  author: someone
source:
  - name: upstream
    version: "2.3.4"'
assert_fails_with "a version: belonging to source[] does not satisfy metadata.version" "missing required frontmatter fields" "$TMPDIR_T/source-list/SKILL.md"

echo ""
echo "--- defect 3: a deeper-nested \`    version:\` is not metadata.version ---"
# `grep -q "  version:"` was an unanchored substring match, so any indentation
# of two spaces or more matched.
write_skill "$TMPDIR_T/deep-indent/SKILL.md" 'name: deep-indent
description: The only version: key sits one level too deep.
metadata:
  provenance:
    version: "1.0.0"'
assert_fails_with "a four-space-indented version: does not satisfy metadata.version" "missing required frontmatter fields" "$TMPDIR_T/deep-indent/SKILL.md"

echo ""
echo "--- defect 4: a version: more than ten lines into the metadata block is FOUND ---"
# The mirror image: the old check reported this one missing.
write_skill "$TMPDIR_T/long-metadata/SKILL.md" 'name: long-metadata
description: A long metadata block whose version sits well past line ten.
metadata:
  a: 1
  b: 2
  c: 3
  d: 4
  e: 5
  f: 6
  g: 7
  h: 8
  i: 9
  j: 10
  k: 11
  version: "1.0.0"'
assert_passes "a version: 13 lines into the metadata block is found" "$TMPDIR_T/long-metadata/SKILL.md"

# ---------------------------------------------------------------------------
# 5. Present is not the same as well formed
# ---------------------------------------------------------------------------
echo ""
echo "--- a present-but-non-semver version is rejected, with its own message ---"
# plugins/bin/.apm/skills/write-docs/SKILL.md carried exactly this through a
# whole PR: the key was present, so a presence-only check had nothing to say.
write_skill "$TMPDIR_T/two-part/SKILL.md" 'name: two-part
description: Its version is two-part, which is a float in YAML, not a version.
metadata:
  version: "1.0"'
assert_fails_with "\"1.0\" is rejected as malformed, not reported as missing" "malformed frontmatter metadata.version" "$TMPDIR_T/two-part/SKILL.md"

echo ""
echo "--- ... and the malformed message quotes the offending value ---"
run_hook "$TMPDIR_T/two-part/SKILL.md"
if [[ "$RUN_OUT" == *'"1.0"'* ]]; then
  pass "the message names the value it rejected"
else
  fail "the message did not quote the rejected value. Output: $RUN_OUT"
fi

echo ""
echo "--- other non-semver shapes ---"
write_skill "$TMPDIR_T/empty-version/SKILL.md" 'name: empty-version
description: The key is present with no value at all.
metadata:
  version:'
assert_fails_with "a valueless version: is rejected" "metadata.version" "$TMPDIR_T/empty-version/SKILL.md"

write_skill "$TMPDIR_T/word-version/SKILL.md" 'name: word-version
description: A non-numeric version.
metadata:
  version: latest'
assert_fails_with "version: latest is rejected" "malformed frontmatter metadata.version" "$TMPDIR_T/word-version/SKILL.md"

echo ""
echo "--- an unquoted three-part version is accepted (both YAML spellings are legal) ---"
write_skill "$TMPDIR_T/unquoted/SKILL.md" 'name: unquoted
description: An unquoted semver, which YAML reads as a string.
metadata:
  version: 0.1.4'
assert_passes "version: 0.1.4 unquoted passes" "$TMPDIR_T/unquoted/SKILL.md"

# ---------------------------------------------------------------------------
# 6. A file that cannot be read as frontmatter must not report green
# ---------------------------------------------------------------------------
echo ""
echo "--- a file with no frontmatter block fails loudly rather than passing vacuously ---"
printf '# Just a document\n\nname: not-frontmatter\ndescription: nor this\n' > "$TMPDIR_T/no-fm.md"
assert_fails_with "a file with no --- block is an error" "no closing YAML frontmatter block" "$TMPDIR_T/no-fm.md"

printf -- '---\nname: unterminated\ndescription: the block is never closed\nmetadata:\n  version: "1.0.0"\n' > "$TMPDIR_T/unterminated.md"
assert_fails_with "an unterminated frontmatter block is an error" "no closing YAML frontmatter block" "$TMPDIR_T/unterminated.md"

echo ""
echo "--- a path that does not exist is skipped, not crashed on ---"
assert_passes "a nonexistent path is ignored" "$TMPDIR_T/nope/SKILL.md"

echo ""
echo "Results: $PASS passed, $FAIL failed"
[[ $FAIL -eq 0 ]]