#!/usr/bin/env bash
# Tests for hooks/bash-pipeline-guard.sh
#
# Convention: bash, `set -uo pipefail`, one PASS:/FAIL: per assertion,
# FAIL=1 aggregate, ALL_OK on full pass.
#
# Each test invokes the hook as a subprocess with real JSON on stdin — never
# source the hook, so we test its actual stdin/stdout/stderr contract.

set -uo pipefail

PASS_COUNT=0
FAIL_COUNT=0
FAIL=0

HOOK="$(cd "$(dirname "$0")/.." && pwd)/bash-pipeline-guard.sh"
[ -x "$HOOK" ] || {
    echo "FATAL: hook not found or not executable: $HOOK" >&2
    exit 2
}
command -v python3 >/dev/null 2>&1 || {
    echo "FATAL: python3 required to build test JSON" >&2
    exit 2
}

pass() {
    printf 'PASS: %s\n' "$1"
    PASS_COUNT=$((PASS_COUNT + 1))
}
fail() {
    printf 'FAIL: %s\n' "$1"
    FAIL_COUNT=$((FAIL_COUNT + 1))
    FAIL=1
}

# Build the JSON envelope the hook expects.
json_for_cmd() {
    python3 -c '
import json, sys
print(json.dumps({"tool_input": {"command": sys.argv[1]}}))
' "$1"
}

# Run the hook with the given stdin payload. Captures stderr to a file (so the
# test name stays readable on stdout) and stdout to nothing.
run_hook_with_stdin() {
    local payload="$1"
    local stderr_file
    stderr_file="$(mktemp)"
    printf '%s' "$payload" | "$HOOK" 2>"$stderr_file" >/dev/null
    HOOK_RC=$?
    HOOK_STDERR="$(cat "$stderr_file")"
    rm -f "$stderr_file"
}

# assert_flag <label> <command>
# Hook must exit 2 and emit a non-empty stderr line.
assert_flag() {
    local label="$1" cmd="$2"
    run_hook_with_stdin "$(json_for_cmd "$cmd")"
    if [ "$HOOK_RC" -eq 2 ] && [ -n "$HOOK_STDERR" ]; then
        pass "$label"
    else
        fail "$label (expected exit=2 + stderr; got exit=$HOOK_RC stderr='$HOOK_STDERR')"
    fi
}

# assert_pass <label> <command>
# Hook must exit 0 (no blocking). Stderr allowed to be non-empty — the brief
# says exit 0 for anything the hook doesn't understand, including cases where
# it might surface information; but in practice our hook is silent on pass.
assert_pass() {
    local label="$1" cmd="$2"
    run_hook_with_stdin "$(json_for_cmd "$cmd")"
    if [ "$HOOK_RC" -eq 0 ]; then
        pass "$label"
    else
        fail "$label (expected exit=0; got exit=$HOOK_RC stderr='$HOOK_STDERR')"
    fi
}

# -----------------------------------------------------------------------------
# SHOULD FLAG — state-changing left side + pipe + && / || / if-test consumer
# -----------------------------------------------------------------------------

assert_flag "git push masked by tail && echo pushed (brief example)" \
    'git push -q origin main 2>&1 | tail -1 && echo "pushed"'

assert_flag "git push simple mask" \
    'git push origin main | head && echo done'

assert_flag "git commit masked" \
    'git commit -m msg file.txt | head && echo done'

assert_flag "git merge masked" \
    'git merge feature | head && echo done'

assert_flag "git rebase masked" \
    'git rebase main | head && echo done'

assert_flag "kubectl apply masked" \
    'kubectl apply -f foo.yaml | head && echo done'

assert_flag "kubectl delete masked" \
    'kubectl delete pod foo | head && echo done'

assert_flag "kubectl patch masked" \
    'kubectl patch svc foo -p {} | head && echo done'

assert_flag "docker push masked" \
    'docker push registry.example.com/img | head && echo done'

assert_flag "helm upgrade masked" \
    'helm upgrade foo bar | head && echo done'

assert_flag "helm install masked" \
    'helm install foo bar | head && echo done'

assert_flag "curl -X POST masked" \
    'curl -X POST https://api.example.com | jq && echo done'

assert_flag "curl -X PUT masked" \
    'curl -X PUT https://api.example.com | jq && echo done'

assert_flag "curl -X DELETE masked" \
    'curl -X DELETE https://api.example.com | jq && echo done'

assert_flag "curl --data masked" \
    "curl --data 'foo' https://api.example.com | jq && echo done"

assert_flag "git push consumed by ||" \
    'git push | head || echo fallback'

assert_flag "multi-pipe state-changing left (git push | tee | tail)" \
    'git push | tee /tmp/log | tail && echo done'

assert_flag "if-test consumes pipeline status (git push)" \
    'if git push origin main | head; then echo done; fi'

assert_flag "if-test consumes pipeline status (kubectl apply)" \
    'if kubectl apply -f foo.yaml | tee /tmp/log; then deploy; fi'

assert_flag "state-changing verb with quoted arg" \
    'git push "origin main" | head && echo done'

# -----------------------------------------------------------------------------
# SHOULD NOT FLAG — read-only, handled, or non-consuming contexts
# -----------------------------------------------------------------------------

assert_pass "no pipe, just &&" \
    'git push origin main && echo done'

assert_pass "pipe with semicolon (no consumption)" \
    'git push origin main | head -1; echo done'

assert_pass "set -o pipefail suppresses flag" \
    'set -o pipefail; git push | head && echo done'

assert_pass "\${PIPESTATUS[0]} suppresses flag" \
    'git push | head; echo ${PIPESTATUS[0]} && echo done'

assert_pass "git log is read-only" \
    'git log | head && echo done'

assert_pass "ls is read-only" \
    'ls | grep foo && echo done'

assert_pass "cat is read-only" \
    'cat file | grep foo && echo done'

assert_pass "grep is read-only" \
    'grep foo file | head && echo done'

assert_pass "curl without write method" \
    'curl https://api.example.com | jq && echo done'

assert_pass "git status is read-only" \
    'git status | head && echo done'

assert_pass "state verb quoted (echo \"git push\")" \
    'echo "git push" | head && echo done'

assert_pass "then keyword is in if-body, not after pipe" \
    'if [ -f foo ]; then git push | head; fi'

# Malformed JSON, empty input, command with quotes and newlines
assert_pass "malformed JSON does not crash" \
    'not json {{{'

assert_pass "empty JSON object does not crash" \
    '{}'

assert_pass "missing tool_input does not crash" \
    '{"foo":"bar"}'

assert_pass "tool_input as non-dict does not crash" \
    '{"tool_input":"oops"}'

assert_pass "empty stdin does not crash" \
    ''

# Command containing quotes and newlines. State verb is inside an echo — must
# not flag. The newlines are encoded as literal "\n" in JSON; the hook sees a
# real newline.
assert_pass "command with embedded newline (state verb quoted)" \
    $'echo "git push" | head && echo done'

# A real multi-line state-changing push that the hook should still flag.
assert_flag "real state-changing push spanning newlines" \
    $'git push \\\n  | head && echo done'

# -----------------------------------------------------------------------------
# Mutation tests — prove the suite can catch real regressions
# -----------------------------------------------------------------------------
#
# Each mutation rewrites one piece of the matcher in a temp copy of the hook,
# runs a previously-passing case through it, and expects the hook to either
# fail to flag (when we broke detection of a flag case) or unexpectedly flag
# (when we broke detection of a pass case). A mutation that does not change
# the outcome is a test that cannot fail.

echo
echo "--- Mutation tests ---"

# Apply a string substitution to a copy of the hook. Use python so we don't
# fight BRE/ERE escaping.
apply_mutation() {
    local hook_src="$1" mutation="$2" out="$3"
    python3 -c '
import sys
old, new = sys.argv[1].split("=>", 1)
with open(sys.argv[2]) as f:
    src = f.read()
if old not in src:
    sys.stderr.write("mutation pattern not found: " + repr(old) + "\n")
    sys.exit(1)
with open(sys.argv[3], "w") as f:
    f.write(src.replace(old, new, 1))
' "$mutation" "$hook_src" "$out"
}

# verify_mutation <name> <mutation> <cmd> <expected>
#   expected = "flag"     → the broken hook must no longer flag this should-flag case
#   expected = "no-flag"  → the broken hook must no longer crash or block a pass case
verify_mutation() {
    local name="$1" mutation="$2" cmd="$3" expected="$4"
    local broken
    broken="$(mktemp -t bpgmut.XXXXXX)" || {
        fail "mutation $name: mktemp failed"
        return
    }
    if ! apply_mutation "$HOOK" "$mutation" "$broken"; then
        fail "mutation $name: could not apply"
        rm -f "$broken"
        return
    fi
    chmod +x "$broken"
    local stderr_file rc stderr_content
    stderr_file="$(mktemp)"
    json_for_cmd "$cmd" | "$broken" 2>"$stderr_file" >/dev/null
    rc=$?
    stderr_content="$(cat "$stderr_file")"
    rm -f "$stderr_file" "$broken"

    case "$expected" in
        flag)
            if [ "$rc" -eq 2 ]; then
                fail "mutation $name: still flags (rc=$rc) — test did NOT go red"
            else
                pass "mutation $name: no longer flags (rc=$rc) — test went red"
            fi
            ;;
        no-flag)
            if [ "$rc" -eq 0 ]; then
                fail "mutation $name: pass-case still passes (rc=$rc) — test did NOT go red"
            else
                pass "mutation $name: pass-case now fails (rc=$rc stderr=$stderr_content) — test went red"
            fi
            ;;
    esac
}

MUTATION_OK=1

# Mutation A: kill the git-push pattern. The flag-case must stop being flagged.
verify_mutation "git-push pattern" \
    'r"\bgit\s+push\b"=>r"\bgit\s+pull\b"' \
    'git push -q origin main 2>&1 | tail -1 && echo "pushed"' \
    "flag"

# Mutation B: never consume \|| when present. The flag-case with && stays flagged,
# so instead break the && check.
verify_mutation "and-or consumption check" \
    're.search(r"&&|\|\|", rest)=>re.search(r"XXX", rest)' \
    'git push | head && echo done' \
    "flag"

# Mutation C: treat every `|` as a `||` and skip it, so the parser thinks
# the command has no single pipe and never flags.
verify_mutation "single-pipe detection" \
    'if c == "|" and i + 1 < len(cmd) and cmd[i + 1] == "|":=>if c == "|" or i + 1 < len(cmd) and cmd[i + 1] == "|":' \
    'git push -q origin main 2>&1 | tail -1 && echo "pushed"' \
    "flag"

# Mutation D: drop the curl-with-write branch so a state-changing curl stops
# being flagged.
verify_mutation "curl write-method detection" \
    'verb = "curl"=>verb = "WEB' \
    'curl -X POST https://api.example.com | jq && echo done' \
    "flag"

# Mutation E: kill the `then` check so the if-context case stops being flagged.
verify_mutation "then-keyword check" \
    're.search(r"\bthen\b", rest)=>re.search(r"XXXXX", rest)' \
    'if git push origin main | head; then echo done; fi' \
    "flag"

# Mutation F: kill the PIPESTATUS bailout so a should-pass command with
# PIPESTATUS now incorrectly flags.
verify_mutation "PIPESTATUS bailout" \
    're.search(r"\$\{?PIPESTATUS", cmd)=>re.search(r"\$\{?XXXXXXXX", cmd)' \
    'git push | head; echo ${PIPESTATUS[0]} && echo done' \
    "no-flag"

# -----------------------------------------------------------------------------
# Summary
# -----------------------------------------------------------------------------

echo
echo "Passed: $PASS_COUNT"
echo "Failed: $FAIL_COUNT"

if [ "$FAIL" -eq 0 ]; then
    echo "ALL_OK"
    exit 0
else
    exit 1
fi