#!/usr/bin/env bash
# check_the_checker for scripts/pr-watch. Every case is a state this repo
# actually hit; three of them are watchers that exited green while wrong.
set -uo pipefail

here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
WATCH="$here/pr-watch"
work="$(mktemp -d)"
trap 'rm -rf "$work"' EXIT

pass=0; fail=0
ok()  { printf '  ok   %s\n' "$1"; pass=$((pass+1)); }
bad() { printf '  FAIL %s (exit %s, wanted %s)\n' "$1" "$2" "$3"; fail=$((fail+1)); }

# $1 name, $2 expected exit, $3 fixture dir, rest: extra args
run_case() {
  local name="$1" want="$2" dir="$3"; shift 3
  PR_WATCH_FIXTURE_DIR="$dir" "$WATCH" 1 --interval 0 --timeout 1 "$@" >/dev/null 2>&1
  local got=$?
  [ "$got" = "$want" ] && ok "$name" || bad "$name" "$got" "$want"
}

# Like run_case but captures stdout for content checks
run_case_capture() {
  local name="$1" want="$2" dir="$3"; shift 3
  local out="$work/output.txt"
  PR_WATCH_FIXTURE_DIR="$dir" "$WATCH" 1 --interval 0 --timeout 1 "$@" >"$out" 2>&1
  local got=$?
  [ "$got" = "$want" ] && ok "$name" || bad "$name" "$got" "$want"
  cat "$out"
}

mk() { mkdir -p "$1"; cat > "$1/$2"; }

# Create empty pr-reviews fixtures so pr-watch can call pr-reviews in fixture mode.
# $1 dir, $2 head (must match the pr-watch fixture's headRefOid)
mk_reviews_empty() {
  local dir="$1" head="$2"
  mkdir -p "$dir"
  printf '{"headRefOid":"%s","reviews":[]}\n' "$head" > "$dir/last.pr.json"
  echo '[]' > "$dir/last.inline.json"
  echo '[]' > "$dir/last.issue.json"
}

# Create pr-reviews fixtures with a review. $1 dir, $2 head, $3 review commit
mk_reviews_with_review() {
  local dir="$1" head="$2" review_commit="$3"
  mkdir -p "$dir"
  cat > "$dir/last.pr.json" <<EOF
{"headRefOid":"$head","reviews":[{"submittedAt":"2026-09-25T12:00:00Z","state":"COMMENTED","author":{"login":"copilot"},"commit":{"oid":"$review_commit"},"body":"Test review body"}]}
EOF
  echo '[]' > "$dir/last.inline.json"
  echo '[]' > "$dir/last.issue.json"
}

# The state a fresh push is in: the PR exists, no check has registered yet.
# A watcher keyed on "nothing pending" calls this finished and green.
mk "$work/none" last.json <<'EOF'
{"headRefOid":"aaaaaaaaaaaa","mergeable":"MERGEABLE","mergeStateStatus":"CLEAN","statusCheckRollup":[]}
EOF
run_case "no checks registered yet is not success" 3 "$work/none"

# conclusion is a STRING, empty while running -- never null. A null test
# matches nothing, so every check looks finished.
mk "$work/running" last.json <<'EOF'
{"headRefOid":"aaaaaaaaaaaa","mergeable":"MERGEABLE","mergeStateStatus":"UNSTABLE","statusCheckRollup":[
 {"name":"build","status":"IN_PROGRESS","conclusion":""},
 {"name":"test","status":"COMPLETED","conclusion":"SUCCESS"}]}
EOF
run_case "a running check with an empty conclusion is not finished" 3 "$work/running"

mk "$work/green" last.json <<'EOF'
{"headRefOid":"aaaaaaaaaaaa","mergeable":"MERGEABLE","mergeStateStatus":"CLEAN","statusCheckRollup":[
 {"name":"build","status":"COMPLETED","conclusion":"SUCCESS"},
 {"name":"skipped","status":"COMPLETED","conclusion":"SKIPPED"}]}
EOF
mk_reviews_empty "$work/green" "aaaaaaaaaaaa"
run_case "all completed and green" 0 "$work/green"

# ── Reviews integration ────────────────────────────────────────────────────
# pr-watch now calls pr-reviews after checks are green. Test that it works.
mk "$work/green-reviews" last.json <<'EOF'
{"headRefOid":"aaaaaaaaaaaa","mergeable":"MERGEABLE","mergeStateStatus":"CLEAN","statusCheckRollup":[
 {"name":"build","status":"COMPLETED","conclusion":"SUCCESS"}]}
EOF
mk_reviews_with_review "$work/green-reviews" "aaaaaaaaaaaa" "aaaaaaaaaaaa"
out=$(run_case_capture "green with reviews shows review output" 0 "$work/green-reviews")
if echo "$out" | grep -q "pr-reviews:"; then
  ok "green with reviews prints pr-reviews output"
else
  bad "green with reviews prints pr-reviews output" "no pr-reviews output" "pr-reviews: in output"
fi

# --no-reviews skips the review printout
out=$(run_case_capture "--no-reviews skips review output" 0 "$work/green-reviews" --no-reviews)
if echo "$out" | grep -q "pr-reviews:"; then
  bad "--no-reviews skips review output" "pr-reviews in output" "no pr-reviews"
else
  ok "--no-reviews actually skips review output"
fi

# pr-reviews failure: if pr-reviews fails, pr-watch exits 6 (not 0)
# Create a green fixture with MALFORMED review fixtures so pr-reviews fails
mk "$work/green-bad-reviews" last.json <<'EOF'
{"headRefOid":"aaaaaaaaaaaa","mergeable":"MERGEABLE","mergeStateStatus":"CLEAN","statusCheckRollup":[
 {"name":"build","status":"COMPLETED","conclusion":"SUCCESS"}]}
EOF
# Create malformed JSON that will cause jq to fail in pr-reviews
echo 'NOT VALID JSON' > "$work/green-bad-reviews/last.pr.json"
echo '[]' > "$work/green-bad-reviews/last.inline.json"
echo '[]' > "$work/green-bad-reviews/last.issue.json"
run_case "pr-reviews failure exits 6" 6 "$work/green-bad-reviews"

mk "$work/red" last.json <<'EOF'
{"headRefOid":"aaaaaaaaaaaa","mergeable":"MERGEABLE","mergeStateStatus":"UNSTABLE","statusCheckRollup":[
 {"name":"build","status":"COMPLETED","conclusion":"FAILURE"}]}
EOF
run_case "a failed check fails" 1 "$work/red"

mk "$work/conflict" last.json <<'EOF'
{"headRefOid":"aaaaaaaaaaaa","mergeable":"CONFLICTING","mergeStateStatus":"DIRTY","statusCheckRollup":[
 {"name":"build","status":"COMPLETED","conclusion":"SUCCESS"}]}
EOF
run_case "green checks on a conflicting PR still fail" 1 "$work/conflict"

# The one that cost a real fix: a verdict about a tree that no longer exists
# reads as a pass. PR #67 merged at a head that predated its correction.
mkdir -p "$work/moved"
cat > "$work/moved/1.json" <<'EOF'
{"headRefOid":"aaaaaaaaaaaa","mergeable":"MERGEABLE","mergeStateStatus":"UNSTABLE","statusCheckRollup":[
 {"name":"build","status":"IN_PROGRESS","conclusion":""}]}
EOF
cat > "$work/moved/last.json" <<'EOF'
{"headRefOid":"bbbbbbbbbbbb","mergeable":"MERGEABLE","mergeStateStatus":"CLEAN","statusCheckRollup":[
 {"name":"build","status":"COMPLETED","conclusion":"SUCCESS"}]}
EOF
run_case "a head that moves mid-wait is not a pass" 2 "$work/moved" --timeout 60

run_case "--expect refuses a different head" 2 "$work/green" --expect bbbbbbbb
run_case "--expect accepts a prefix of the head" 0 "$work/green" --expect aaaa

# improvise-edpl. GitHub computes mergeability lazily: for a while after the
# base moves it reports UNKNOWN, and PRs #172 and #179 both exited 0 there.
# This is the shape both had: every check green, mergeability unresolved.
green_rollup='[{"name":"build","status":"COMPLETED","conclusion":"SUCCESS"}]'
red_rollup='[{"name":"build","status":"COMPLETED","conclusion":"FAILURE"}]'
# $1 dir, $2 file, $3 mergeable, $4 mergeStateStatus, $5 rollup (JSON values)
state() {
  mkdir -p "$1"
  printf '{"headRefOid":"aaaaaaaaaaaa","mergeable":%s,"mergeStateStatus":%s,"statusCheckRollup":%s}\n' \
    "$3" "$4" "$5" > "$1/$2"
}

state "$work/unk-conflict" 1.json '"UNKNOWN"' '"UNKNOWN"' "$green_rollup"
state "$work/unk-conflict" last.json '"CONFLICTING"' '"DIRTY"' "$green_rollup"
run_case "UNKNOWN that resolves to CONFLICTING fails" 1 "$work/unk-conflict" --timeout 60

state "$work/unk-clean" 1.json '"UNKNOWN"' '"UNKNOWN"' "$green_rollup"
state "$work/unk-clean" 2.json '"MERGEABLE"' '"UNKNOWN"' "$green_rollup"
state "$work/unk-clean" last.json '"MERGEABLE"' '"CLEAN"' "$green_rollup"
run_case "UNKNOWN that resolves to MERGEABLE/CLEAN passes" 0 "$work/unk-clean" --timeout 60

state "$work/unk-forever" last.json '"UNKNOWN"' '"UNKNOWN"' "$green_rollup"
run_case "UNKNOWN until the timeout is a timeout, not a pass" 3 "$work/unk-forever"

# A failed check fails whatever mergeability says; waiting on it would turn a
# known red into a timeout.
state "$work/unk-red" last.json '"UNKNOWN"' '"UNKNOWN"' "$red_rollup"
run_case "a failed check fails without waiting on mergeability" 1 "$work/unk-red" --timeout 0

# The whole table, enumerated rather than hand-picked, every check green. The
# rule it states is in context/code/tooling.md, "pr-watch and mergeability".
for m in MERGEABLE CONFLICTING UNKNOWN; do
  for s in BEHIND BLOCKED CLEAN DIRTY DRAFT HAS_HOOKS UNKNOWN UNSTABLE SOMETHING_NEW null; do
    if [ "$m" = CONFLICTING ]; then want=1
    elif [ "$m" = UNKNOWN ] || [ "$s" = UNKNOWN ]; then want=3
    else case "$s" in CLEAN|UNSTABLE|HAS_HOOKS) want=0 ;; BLOCKED) want=3 ;; *) want=1 ;; esac
    fi
    sv="\"$s\""; [ "$s" = null ] && sv=null
    state "$work/table-$m-$s" last.json "\"$m\"" "$sv" "$green_rollup"
    # Add review fixtures for cases that exit 0 (pr-watch calls pr-reviews)
    if [ "$want" = 0 ]; then
      mk_reviews_empty "$work/table-$m-$s" "aaaaaaaaaaaa"
    fi
    run_case "table: $m/$s" "$want" "$work/table-$m-$s" --timeout 0
  done
done

# improvise-zlj2. The required "Browser harness" check comes from a job that
# `needs: build`, so its check run does not exist until build finishes. In that
# gap every registered check is green and GitHub says MERGEABLE/BLOCKED. The
# rollup below is PR #189's, verbatim; the gap states drop or rewind entries.
cat > "$work/rollup.jsonl" <<'EOF'
{"__typename":"CheckRun","completedAt":"2026-09-23T04:41:53Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261571/job/107047406461","name":"Build all bundles","startedAt":"2026-09-23T04:40:15Z","status":"COMPLETED","workflowName":"CI"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:40:32Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261564/job/107047406233","name":"plan","startedAt":"2026-09-23T04:40:14Z","status":"COMPLETED","workflowName":"Release"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:40:32Z","conclusion":"SKIPPED","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261564/job/107047482378","name":"build-local-artifacts (${{ join(matrix.targets, ', ') }})","startedAt":"2026-09-23T04:40:32Z","status":"COMPLETED","workflowName":"Release"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:42:22Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261571/job/107047406506","name":"Test and lint (host)","startedAt":"2026-09-23T04:40:16Z","status":"COMPLETED","workflowName":"CI"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:40:32Z","conclusion":"SKIPPED","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261564/job/107047482733","name":"build-global-artifacts","startedAt":"2026-09-23T04:40:32Z","status":"COMPLETED","workflowName":"Release"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:40:40Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261571/job/107047406409","name":"wasm32 check (browser bundle crates)","startedAt":"2026-09-23T04:40:15Z","status":"COMPLETED","workflowName":"CI"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:40:32Z","conclusion":"SKIPPED","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261564/job/107047482801","name":"host","startedAt":"2026-09-23T04:40:33Z","status":"COMPLETED","workflowName":"Release"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:40:25Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261571/job/107047406415","name":"Browser JS unit tests (node --test)","startedAt":"2026-09-23T04:40:14Z","status":"COMPLETED","workflowName":"CI"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:40:32Z","conclusion":"SKIPPED","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261564/job/107047483313","name":"announce","startedAt":"2026-09-23T04:40:33Z","status":"COMPLETED","workflowName":"Release"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:41:17Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261571/job/107047406264","name":"Knowledge base consistency","startedAt":"2026-09-23T04:40:14Z","status":"COMPLETED","workflowName":"CI"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:40:39Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261571/job/107047406373","name":"Lint the harness crate","startedAt":"2026-09-23T04:40:14Z","status":"COMPLETED","workflowName":"CI"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:44:17Z","conclusion":"SUCCESS","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261571/job/107047753280","name":"Browser harness (OPFS contract + shell)","startedAt":"2026-09-23T04:41:56Z","status":"COMPLETED","workflowName":"CI"}
{"__typename":"CheckRun","completedAt":"2026-09-23T04:44:18Z","conclusion":"SKIPPED","detailsUrl":"https://github.com/fiddlerwoaroof/improvise/actions/runs/35819261571/job/107048259684","name":"Deploy to GitHub Pages","startedAt":"2026-09-23T04:44:18Z","status":"COMPLETED","workflowName":"CI"}
EOF
harness='Browser harness (OPFS contract + shell)'
deploy='Deploy to GitHub Pages'
# $1 dir, $2 file, $3 mergeable, $4 state, $5 jq filter over the rollup array
gap_state() {
  state "$1" "$2" "\"$3\"" "\"$4\"" "$(jq -cs "$5" "$work/rollup.jsonl")"
}
build_running='map(if .name == "Build all bundles" then .status = "IN_PROGRESS" | .conclusion = "" else . end)'
not_yet="map(select(.name != \"$harness\" and .name != \"$deploy\"))"
harness_running="map(if .name == \"$harness\" then .status = \"IN_PROGRESS\" | .conclusion = \"\" else . end) | map(select(.name != \"$deploy\"))"
gap_state "$work/gap" 1.json MERGEABLE BLOCKED "$not_yet | $build_running"
gap_state "$work/gap" 2.json MERGEABLE BLOCKED "$not_yet"
gap_state "$work/gap" 3.json MERGEABLE BLOCKED "$harness_running"
gap_state "$work/gap" last.json MERGEABLE CLEAN '.'
mk_reviews_empty "$work/gap" "aaaaaaaaaaaa"
run_case "the needs-gap before the required check registers is not a failure" 0 "$work/gap" --timeout 60

gap_state "$work/gap-never" last.json MERGEABLE BLOCKED "$not_yet"
run_case "a required check that never registers is a timeout" 3 "$work/gap-never"

# improvise-9pfs. Here a failed REQUIRED check reports MERGEABLE/BLOCKED, not
# UNSTABLE. The table above holds only green rollups, so this red was unpinned.
gap_state "$work/blocked-red" last.json MERGEABLE BLOCKED \
  'map(if .name == "Test and lint (host)" then .conclusion = "FAILURE" else . end)'
run_case "a failed required check under MERGEABLE/BLOCKED fails without waiting" 1 \
  "$work/blocked-red" --timeout 0

# improvise-1qaa/29w2. Each ended fixture is a shape GitHub returned live (#189,
# #74, #46); the last is the one a waiting loop would sit on.
# $1 dir, $2 file, $3 head, $4 state, $5 mergeable, $6 mergeStateStatus
ended() {
  mkdir -p "$1"
  printf '{"headRefOid":"%s","state":"%s","mergeable":"%s","mergeStateStatus":"%s","statusCheckRollup":%s}\n' \
    "$3" "$4" "$5" "$6" "$green_rollup" > "$1/$2"
}
for shape in "MERGED UNKNOWN UNKNOWN" "CLOSED CONFLICTING DIRTY" "CLOSED MERGEABLE BLOCKED"; do
  set -- $shape
  d="$work/ended-$1-$3"
  ended "$d" last.json aaaaaaaaaaaa "$1" "$2" "$3"
  run_case "a $1 PR at $2/$3 ends the watch as no longer open" 5 "$d" --timeout 5
  polls="$(cat "$d/.poll" 2>/dev/null || echo 0)"
  [ "$polls" = 1 ] && ok "a $1 PR at $2/$3 is read once, not waited on" \
    || bad "a $1 PR at $2/$3 is read once, not waited on (polls)" "$polls" 1
done

# improvise-24lz. A merge at a head the watcher never saw is the PR #67 hazard,
# so a moved head outranks a closed PR, with or without --expect.
state "$work/moved-merged" 1.json '"MERGEABLE"' '"UNSTABLE"' \
  '[{"name":"build","status":"IN_PROGRESS","conclusion":""}]'
ended "$work/moved-merged" last.json bbbbbbbbbbbb MERGED UNKNOWN UNKNOWN
run_case "a head that moves and then merges is not reported as merged" 2 \
  "$work/moved-merged" --timeout 60
ended "$work/merged-elsewhere" last.json bbbbbbbbbbbb MERGED UNKNOWN UNKNOWN
run_case "a PR merged at a head other than --expect is a head mismatch" 2 \
  "$work/merged-elsewhere" --expect aaaa --timeout 5

# improvise-h3ni. The head must stay pinned across the UNKNOWN wait, or a
# verdict about b is reported as a verdict about a.
state "$work/unk-moved" 1.json '"UNKNOWN"' '"UNKNOWN"' "$green_rollup"
state "$work/unk-moved" 2.json '"UNKNOWN"' '"UNKNOWN"' "$green_rollup"
state "$work/unk-moved" last.json '"MERGEABLE"' '"CLEAN"' "$green_rollup"
for f in 2.json last.json; do
  sed 's/aaaaaaaaaaaa/bbbbbbbbbbbb/' "$work/unk-moved/$f" > "$work/unk-moved/$f.new"
  mv -f "$work/unk-moved/$f.new" "$work/unk-moved/$f"
done
run_case "a head that moves during the UNKNOWN wait is not a pass" 2 "$work/unk-moved" --timeout 60

printf '\npr-watch-test: %d passed, %d failed\n' "$pass" "$fail"
[ "$fail" -eq 0 ]