#!/bin/sh
set -eu

if [ "$#" -ne 1 ]; then
    echo "usage: $0 LONG_CONTEXT_SERVER_GATE" >&2
    exit 2
fi

runner=$1
fixture=$(mktemp -d /private/tmp/gem-server-gate-resume.XXXXXX)
listener_pid=
cleanup()
{
    if [ -n "$listener_pid" ] && kill -0 "$listener_pid" 2>/dev/null; then
        kill "$listener_pid"
        wait "$listener_pid" 2>/dev/null || true
    fi
    rm -rf "$fixture"
}
trap cleanup EXIT INT TERM HUP

mkdir -p "$fixture/build" "$fixture/scripts"
printf 'fixture model\n' > "$fixture/model.gguf"
printf 'fixture prompt\n' > "$fixture/prompt.txt"
# The single-quoted fragments below are the literal body of a generated fixture.
# shellcheck disable=SC2016
printf '%s\n' '#!/bin/sh' \
    'set -eu' \
    'if [ "$1" = print-config ]; then' \
    '    if [ -e .changed-config ]; then' \
    '        printf '\''{"engine":"gem-native-c-metal","context":4098,"kv_type":"f32","route":"changed"}\n'\''' \
    '    else' \
    '        printf '\''{"engine":"gem-native-c-metal","context":4098,"kv_type":"f32","route":"fixture"}\n'\''' \
    '    fi' \
    '    exit 0' \
    'fi' \
    ': > .serve-attempted' \
    'printf '\''serve must not run during a completed-sample resume\n'\'' >&2' \
    'exit 99' > "$fixture/build/gem"
printf '%s\n' '#!/bin/sh' 'printf '\''{"token_count":4096}\n'\''' \
    > "$fixture/build/gem-tokenize"
printf '%s\n' '#!/bin/sh' 'exit 99' > "$fixture/scripts/server-stream-probe.sh"
chmod +x "$fixture/build/gem" "$fixture/build/gem-tokenize" \
    "$fixture/scripts/server-stream-probe.sh"

port=$((20000 + ($$ % 20000)))
nc -l 127.0.0.1 "$port" >/dev/null 2>&1 &
listener_pid=$!
attempt=0
while ! lsof -nP -iTCP:"$port" -sTCP:LISTEN >/dev/null 2>&1; do
    attempt=$((attempt + 1))
    if [ "$attempt" -ge 50 ]; then
        echo "fixture listener did not become ready" >&2
        exit 1
    fi
    sleep 0.02
done

set +e
(
    cd "$fixture"
    GEM_MODEL_SHA256=0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef \
        GEM_STREAM_MAX_TOKENS=2 \
        "$runner" model.gguf 4098 prompt.txt results "$port"
)
initial_status=$?
set -e
if [ "$initial_status" -ne 1 ]; then
    echo "initial occupied-port run returned $initial_status, expected 1" >&2
    exit 1
fi
kill "$listener_pid"
wait "$listener_pid" 2>/dev/null || true
listener_pid=

set +e
(
    cd "$fixture"
    GEM_MODEL_SHA256=0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef \
        GEM_STREAM_MAX_TOKENS=2 GEM_GATE_PREFLIGHT_MIN_TOKENS=0 \
        GEM_GATE_MAX_LOAD_PER_CPU=0.000001 \
        "$runner" model.gguf 4098 prompt.txt results-busy "$port" >/dev/null 2>&1
)
preflight_status=$?
set -e
if [ "$preflight_status" -ne 1 ] ||
   ! jq -e '.status == "fail"' "$fixture/results-busy/host-preflight-1.json" >/dev/null ||
   [ -e "$fixture/.serve-attempted" ]; then
    echo "busy-host preflight did not fail before server launch" >&2
    exit 1
fi

sample=1
while [ "$sample" -le 3 ]; do
    printf 'gem: prompt prefill 4096/4096 tokens (100.00%%), fixture sample %s\n' \
        "$sample" > "$fixture/results/server-$sample.log"
    printf 'data: {"choices":[{"delta":{"content":"x"}}]}\n\ndata: [DONE]\n\n' \
        > "$fixture/results/stream-$sample.sse"
    jq -n --argjson sample "$sample" \
        '{schema_version: 1, engine: "gem-native-c-metal", model: "gemma4",
          requested_max_tokens: 2, http_code: 200,
          header_ttfb_seconds: 0.01,
          first_visible_event_seconds: (0.02 + ($sample / 1000)),
          completion_seconds: 0.04, visible_event_count: 1,
          finish_reason: "stop",
          usage: {prompt_tokens: 4096, completion_tokens: 2, total_tokens: 4098}}' \
        > "$fixture/results/measurement-$sample.json"
    sample=$((sample + 1))
done

(
    cd "$fixture"
    GEM_MODEL_SHA256=0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef \
        GEM_STREAM_MAX_TOKENS=2 GEM_GATE_RESUME=1 \
        "$runner" model.gguf 4098 prompt.txt results "$port" >/dev/null
)
jq -e '.repetitions == 3 and .resumed_samples == 3 and (.samples | length) == 3' \
    "$fixture/results/summary.json" >/dev/null

printf 'nonempty but missing final prefill record\n' > "$fixture/results/server-2.log"
set +e
(
    cd "$fixture"
    GEM_MODEL_SHA256=0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef \
        GEM_STREAM_MAX_TOKENS=2 GEM_GATE_RESUME=1 \
        "$runner" model.gguf 4098 prompt.txt results "$port" >/dev/null 2>&1
)
log_status=$?
set -e
if [ "$log_status" -ne 1 ] || [ ! -e "$fixture/.serve-attempted" ]; then
    echo "missing final prefill record was silently resumed" >&2
    exit 1
fi
rm "$fixture/.serve-attempted"
printf 'gem: prompt prefill 4096/4096 tokens (100.00%%), fixture sample 2\n' \
    > "$fixture/results/server-2.log"

touch "$fixture/.changed-config"
set +e
(
    cd "$fixture"
    GEM_MODEL_SHA256=0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef \
        GEM_STREAM_MAX_TOKENS=2 GEM_GATE_RESUME=1 \
        "$runner" model.gguf 4098 prompt.txt results "$port" >/dev/null 2>&1
)
config_status=$?
set -e
if [ "$config_status" -ne 2 ]; then
    echo "changed native configuration returned $config_status, expected 2" >&2
    exit 1
fi
rm "$fixture/.changed-config"

jq '.prompt_sha256 = "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"' \
    "$fixture/results/gate-config.json" > "$fixture/results/gate-config.tmp"
mv "$fixture/results/gate-config.tmp" "$fixture/results/gate-config.json"
set +e
(
    cd "$fixture"
    GEM_MODEL_SHA256=0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef \
        GEM_STREAM_MAX_TOKENS=2 GEM_GATE_RESUME=1 \
        "$runner" model.gguf 4098 prompt.txt results "$port" >/dev/null 2>&1
)
provenance_status=$?
set -e
if [ "$provenance_status" -ne 2 ]; then
    echo "changed gate provenance returned $provenance_status, expected 2" >&2
    exit 1
fi