package builtins_test

import (
	"bytes"
	"context"
	"github.com/stretchr/testify/assert"
	"strings"
	"testing"
	"testing/fstest"
	"ucl.lmika.dev/ucl"
	"ucl.lmika.dev/ucl/builtins"
)

var testCsvFS = fstest.MapFS{
	"test.csv": &fstest.MapFile{
		Data: []byte(strings.Join([]string{
			"wind,dir,bearing",
			"north,N,0",
			"south,S,180",
			"east,E,90",
			"west,W,270",
		}, "\n")),
	},
}

func TestCSV_ReadRecord(t *testing.T) {
	tests := []struct {
		descr   string
		eval    string
		wantOut string
	}{
		{descr: "read csv 1", eval: `csv:each-record "test.csv" { |r h| echo $r.(0) }`, wantOut: "north\nsouth\neast\nwest\n"},
		{descr: "read csv 2", eval: `csv:each-record "test.csv" { |r h| echo $r.($h.dir) }`, wantOut: "N\nS\nE\nW\n"},
		{descr: "read csv 3", eval: `csv:each-record "test.csv" { |r h| echo $r.($h.bearing) "-" $r.($h.dir) }`, wantOut: "0-N\n180-S\n90-E\n270-W\n"},
		{descr: "read csv 4", eval: `csv:each-record "test.csv" { |r h| echo $h.bearing }`, wantOut: "2\n2\n2\n2\n"},
		{descr: "read csv 5", eval: `csv:each-record "test.csv" {}`, wantOut: ""},
	}

	for _, tt := range tests {
		t.Run(tt.descr, func(t *testing.T) {
			var bfr bytes.Buffer

			inst := ucl.New(
				ucl.WithModule(builtins.CSV(testCsvFS)),
				ucl.WithOut(&bfr),
			)

			_, err := inst.EvalString(context.Background(), tt.eval)
			assert.NoError(t, err)
			assert.Equal(t, tt.wantOut, bfr.String())
		})
	}
}