package converter

import (
	"fmt"
	"os"
	"path"
	"strings"
	"testing"
	"time"

	"github.com/grafana/grafana-plugin-sdk-go/experimental"
	"github.com/grafana/grafana/pkg/infra/httpclient"
	jsoniter "github.com/json-iterator/go"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

const update = false

var files = []string{
	"prom-labels",
	"prom-matrix",
	"prom-matrix-with-nans",
	"prom-matrix-histogram-no-labels",
	"prom-matrix-histogram-partitioned",
	"prom-vector-histogram-no-labels",
	"prom-vector",
	"prom-string",
	"prom-scalar",
	"prom-series",
	"prom-warnings",
	"prom-error",
	"prom-exemplars-a",
	"prom-exemplars-b",
	"prom-exemplars-diff-labels",
	"loki-streams-a",
	"loki-streams-b",
	"loki-streams-c",
}

func TestReadPromFrames(t *testing.T) {
	for _, name := range files {
		t.Run(name, runScenario(name, Options{}))
	}
}

func TestReadLimited(t *testing.T) {
	for _, name := range files {
		p := path.Join("testdata", name+".json")
		stat, err := os.Stat(p)
		require.NoError(t, err)
		size := stat.Size()

		for i := int64(10); i < size-1; i += size / 10 {
			t.Run(fmt.Sprintf("%v_%v", name, i), func(t *testing.T) {
				//nolint:gosec
				f, err := os.Open(p)
				require.NoError(t, err)
				mbr := httpclient.MaxBytesReader(f, i)

				iter := jsoniter.Parse(jsoniter.ConfigDefault, mbr, 1024)
				rsp := ReadPrometheusStyleResult(iter, Options{})

				require.ErrorContains(t, rsp.Error, "response body too large")
			})
		}
	}
}

func runScenario(name string, opts Options) func(t *testing.T) {
	return func(t *testing.T) {
		// Safe to disable, this is a test.
		// nolint:gosec
		f, err := os.Open(path.Join("testdata", name+".json"))
		require.NoError(t, err)

		iter := jsoniter.Parse(jsoniter.ConfigDefault, f, 1024)
		rsp := ReadPrometheusStyleResult(iter, opts)

		if strings.Contains(name, "error") {
			require.Error(t, rsp.Error)
			return
		}
		require.NoError(t, rsp.Error)

		fname := name + "-frame"
		experimental.CheckGoldenJSONResponse(t, "testdata", fname, &rsp, update)
	}
}

func TestTimeConversions(t *testing.T) {
	// include millisecond precision
	assert.Equal(t,
		time.Date(2020, time.September, 14, 15, 22, 25, 479000000, time.UTC),
		timeFromFloat(1600096945.479))

	ti, err := timeFromLokiString("1645030246277587968")
	require.NoError(t, err)
	// Loki date parsing
	assert.Equal(t,
		time.Date(2022, time.February, 16, 16, 50, 46, 277587968, time.UTC),
		ti)

	ti, err = timeFromLokiString("2000000000000000000")
	require.NoError(t, err)

	assert.Equal(t,
		time.Date(2033, time.May, 18, 3, 33, 20, 0, time.UTC),
		ti)
}