package commandkit

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"reflect"
	"strings"
	"testing"
	"text/template"
)

func TestRenderReportAutomaticShapes(t *testing.T) {
	for _, tc := range []struct {
		name  string
		value any
		text  string
		yaml  bool
	}{
		{"string", "hello", "hello\n", false},
		{"number", json.Number("123456789012345678901234567890"), "123456789012345678901234567890\n", false},
		{"boolean", false, "false\n", false},
		{"strings", []string{"one", "two"}, "one\ntwo\n", false},
		{"empty strings", []string{}, "", true},
		{"empty map", map[string]any{}, "", true},
		{"null", nil, "", true},
		{"mixed", []any{"a", false}, "", true},
		{"map", map[string]any{"n": json.Number("9007199254740993")}, "", true},
	} {
		t.Run(tc.name, func(t *testing.T) {
			var out bytes.Buffer
			if err := RenderReport(&out, Report{Value: tc.value}, ""); err != nil {
				t.Fatal(err)
			}
			if !tc.yaml {
				if out.String() != tc.text {
					t.Fatalf("got %q want %q", out.String(), tc.text)
				}
				return
			}
			got, err := DecodeYAMLReport(&out)
			if err != nil {
				t.Fatal(err)
			}
			want, err := normalizeReport(tc.value)
			if err != nil {
				t.Fatal(err)
			}
			if !reflect.DeepEqual(got, want) {
				t.Fatalf("got %#v want %#v", got, want)
			}
		})
	}
}

func TestRenderReportTemplatesAndFormats(t *testing.T) {
	tmpl, err := ParseTextTemplate("report", `{{upper .Secret}}/{{.Name}}`, template.FuncMap{"upper": strings.ToUpper})
	if err != nil {
		t.Fatal(err)
	}
	value := struct {
		Name   string `json:"name"`
		Secret string `json:"-"`
	}{"public", "private"}
	var out bytes.Buffer
	if err := RenderReport(&out, Report{value, tmpl}, ""); err != nil {
		t.Fatal(err)
	}
	if out.String() != "PRIVATE/public" {
		t.Fatal(out.String())
	}
	for _, format := range []Format{FormatYAML, FormatJSON} {
		out.Reset()
		if err := RenderReport(&out, Report{value, tmpl}, format); err != nil {
			t.Fatal(err)
		}
		var got any
		if format == FormatYAML {
			got, err = DecodeYAMLReport(&out)
		} else {
			d := json.NewDecoder(&out)
			d.UseNumber()
			err = d.Decode(&got)
		}
		if err != nil {
			t.Fatal(err)
		}
		if !reflect.DeepEqual(got, map[string]any{"name": "public"}) {
			t.Fatalf("got %#v", got)
		}
	}
	out.Reset()
	if err := RenderReport(&out, Report{Value: map[string]any{"n": json.Number("123456789012345678901234567890")}}, FormatText); err != nil {
		t.Fatal(err)
	}
	got, err := DecodeYAMLReport(&out)
	if err != nil || !reflect.DeepEqual(got, map[string]any{"n": json.Number("123456789012345678901234567890")}) {
		t.Fatalf("got %#v: %v", got, err)
	}
}

type reportShortWriter struct{}

func (reportShortWriter) Write(p []byte) (int, error) { return len(p) / 2, nil }

type reportErrorWriter struct{ err error }

func (w reportErrorWriter) Write([]byte) (int, error) { return 0, w.err }

func TestRenderReportErrors(t *testing.T) {
	if _, err := ParseTextTemplate("bad", `{{`, nil); err == nil {
		t.Fatal("invalid template accepted")
	}
	tmpl, err := ParseTextTemplate("bad-execution", `{{.Missing}}`, nil)
	if err != nil {
		t.Fatal(err)
	}
	if err := RenderReport(io.Discard, Report{Value: struct{}{}, TextTemplate: tmpl}, ""); err == nil {
		t.Fatal("template execution succeeded")
	}
	if err := RenderReport(io.Discard, Report{Value: make(chan int)}, FormatJSON); err == nil {
		t.Fatal("unsupported value accepted")
	}
	if err := RenderReport(io.Discard, Report{}, Format("bad")); err == nil {
		t.Fatal("unknown format accepted")
	}
	tmpl, err = ParseTextTemplate("skip-json", `{{if .}}ok{{end}}`, nil)
	if err != nil {
		t.Fatal(err)
	}
	var out bytes.Buffer
	if err := RenderReport(&out, Report{Value: make(chan int), TextTemplate: tmpl}, FormatText); err != nil || out.String() != "ok" {
		t.Fatalf("templated unsupported value: %q, %v", &out, err)
	}
	failure := errors.New("writer failure")
	for _, format := range []Format{FormatText, FormatYAML, FormatJSON} {
		t.Run(string(format), func(t *testing.T) {
			for _, writer := range []struct {
				w    io.Writer
				want error
			}{{reportShortWriter{}, io.ErrShortWrite}, {reportErrorWriter{failure}, failure}} {
				err := RenderReport(writer.w, Report{Value: "content"}, format)
				if !errors.Is(err, writer.want) {
					t.Fatalf("%s: got %v, want %v", fmt.Sprint(writer.w), err, writer.want)
				}
			}
		})
	}
}

func TestRenderReportExplicitFormatsSkipTemplateAndPreserveNumbers(t *testing.T) {
	tmpl, err := ParseTextTemplate("invalid-at-execution", `{{.Missing}}`, nil)
	if err != nil {
		t.Fatal(err)
	}
	value := struct {
		Number json.Number `json:"number"`
	}{json.Number("123456789012345678901234567890")}
	want := map[string]any{"number": json.Number("123456789012345678901234567890")}
	for _, format := range []Format{FormatYAML, FormatJSON} {
		t.Run(string(format), func(t *testing.T) {
			var out bytes.Buffer
			if err := RenderReport(&out, Report{Value: value, TextTemplate: tmpl}, format); err != nil {
				t.Fatal(err)
			}
			var got any
			if format == FormatYAML {
				got, err = DecodeYAMLReport(&out)
			} else {
				dec := json.NewDecoder(&out)
				dec.UseNumber()
				err = dec.Decode(&got)
			}
			if err != nil || !reflect.DeepEqual(got, want) {
				t.Fatalf("got %#v, %v", got, err)
			}
		})
	}
	plain, err := ParseTextTemplate("plain", "content", nil)
	if err != nil {
		t.Fatal(err)
	}
	if err := RenderReport(reportShortWriter{}, Report{TextTemplate: plain}, FormatText); !errors.Is(err, io.ErrShortWrite) {
		t.Fatalf("got %v", err)
	}
}