#!/bin/bash
# Regression coverage for Gitea PR diff construction and fail-closed review behavior.
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
TMP_DIR=$(mktemp -d)
trap 'rm -rf "$TMP_DIR"' EXIT

fail() {
    echo "not ok - $*" >&2
    exit 1
}

assert_contains() {
    local haystack="$1" needle="$2"
    [[ "$haystack" == *"$needle"* ]] || fail "expected output to contain: $needle"
}

# A fresh clone is on main, while PR #795's changes exist only at the provider PR ref.
# The git stub returns the PR patch only when build_diff_context fetches and diffs that
# explicit ref; diffing main...HEAD reproduces the empty/wrong-branch bug.
if [[ "${1:-all}" != "fail-closed" ]]; then
FETCH_LOG="$TMP_DIR/fetch.log"
DIFF_LOG="$TMP_DIR/diff.log"
export FETCH_LOG DIFF_LOG

(
    # shellcheck source=common.sh
    source "$SCRIPT_DIR/common.sh"

    detect_platform() {
        PLATFORM=gitea
        export PLATFORM
    }

    tea() {
        if [[ "$*" == "pr list --fields index,base --output simple" ]]; then
            printf '795 main\n'
            return 0
        fi
        return 1
    }

    git() {
        case "${1:-}" in
            remote)
                printf 'https://git.example.test/mosaicstack/stack.git\n'
                ;;
            fetch)
                printf '%s\n' "$*" >> "$FETCH_LOG"
                ;;
            diff)
                printf '%s\n' "$*" >> "$DIFF_LOG"
                if [[ "$*" == *"refs/remotes/origin/pr/795/head"* && "$*" != *"HEAD"* ]]; then
                    cat <<'DIFF'
diff --git a/pr-change.ts b/pr-change.ts
--- a/pr-change.ts
+++ b/pr-change.ts
@@ -1 +1 @@
-old
+actual-pr-change
DIFF
                fi
                ;;
            *)
                return 1
                ;;
        esac
    }

    diff_context=$(build_diff_context pr 795)
    assert_contains "$diff_context" "actual-pr-change"
)

assert_contains "$(cat "$FETCH_LOG" 2>/dev/null || true)" "refs/pull/795/head"
assert_contains "$(cat "$DIFF_LOG" 2>/dev/null || true)" "refs/remotes/origin/pr/795/head"
if grep -q 'HEAD' "$DIFF_LOG" 2>/dev/null; then
    fail "Gitea PR diff used local HEAD"
fi
echo "ok - Gitea PR mode fetches and diffs the explicit PR head"
fi

# Exercise the CLI path with all provider/network mutations stubbed. An empty PR diff
# must be an actionable nonzero failure before Codex runs and before auto-post can run.
if [[ "${1:-all}" != "pr-head" ]]; then
SANDBOX="$TMP_DIR/sandbox"
mkdir -p "$SANDBOX/tools/codex/schemas" "$SANDBOX/tools/git" "$SANDBOX/bin"
cp "$SCRIPT_DIR/common.sh" "$SCRIPT_DIR/codex-code-review.sh" "$SANDBOX/tools/codex/"
cp "$SCRIPT_DIR/schemas/code-review-schema.json" "$SANDBOX/tools/codex/schemas/"

cat > "$SANDBOX/tools/git/detect-platform.sh" <<'STUB'
detect_platform() { PLATFORM=gitea; export PLATFORM; }
get_repo_info() { printf 'mosaicstack/stack\n'; }
STUB
cat > "$SANDBOX/tools/git/pr-review.sh" <<'STUB'
#!/bin/bash
printf 'POST %s\n' "$*" >> "$POST_LOG"
STUB
chmod +x "$SANDBOX/tools/git/pr-review.sh"

cat > "$SANDBOX/bin/git" <<'STUB'
#!/bin/bash
case "${1:-}" in
    rev-parse) exit 0 ;;
    remote) printf 'https://git.example.test/mosaicstack/stack.git\n' ;;
    fetch) printf 'FETCH %s\n' "$*" >> "$FETCH_LOG" ;;
    diff) exit 0 ;;
    *) exit 1 ;;
esac
STUB
cat > "$SANDBOX/bin/tea" <<'STUB'
#!/bin/bash
if [[ "$*" == "pr list --fields index,base --output simple" ]]; then
    printf '795 main\n'
    exit 0
fi
exit 1
STUB
cat > "$SANDBOX/bin/codex" <<'STUB'
#!/bin/bash
printf 'CODEX %s\n' "$*" >> "$CODEX_LOG"
exit 99
STUB
chmod +x "$SANDBOX/bin/git" "$SANDBOX/bin/tea" "$SANDBOX/bin/codex"

POST_LOG="$TMP_DIR/post.log"
CODEX_LOG="$TMP_DIR/codex.log"
export POST_LOG CODEX_LOG
set +e
PATH="$SANDBOX/bin:$PATH" "$SANDBOX/tools/codex/codex-code-review.sh" -n 795 \
    >"$TMP_DIR/review.stdout" 2>"$TMP_DIR/review.stderr"
review_status=$?
set -e

[[ "$review_status" -ne 0 ]] || fail "empty PR diff returned success instead of failing closed"
[[ ! -s "$CODEX_LOG" ]] || fail "Codex ran for an empty PR diff"
[[ ! -s "$POST_LOG" ]] || fail "review auto-post ran for an empty PR diff"
assert_contains "$(cat "$TMP_DIR/review.stderr")" "Error:"
assert_contains "$(cat "$TMP_DIR/review.stderr")" "PR #795"
echo "ok - empty PR diff fails closed before Codex and auto-post"
fi