package main

import (
	"bytes"
	"context"
	"io"
	"testing"

	commandkit "gitea.maximumdirect.net/eric/CommandKit"
	"gitea.maximumdirect.net/eric/CommandKit/integrations/ckconfig"
	"go.yaml.in/yaml/v4"
)

func TestSimpleAppComparesFixturesAndKeepsDefaultCommands(t *testing.T) {
	app, err := newApp()
	if err != nil {
		t.Fatal(err)
	}
	var output bytes.Buffer
	outcome := app.Execute(context.Background(), []string{"config", "diff", "--config", "fixtures/before.yml", "--against-config", "fixtures/after.yml"}, commandkit.Streams{Out: &output, Err: io.Discard})
	if outcome.Kind != commandkit.OutcomeSuccess {
		t.Fatalf("fixture comparison outcome = %#v", outcome)
	}
	var report yaml.Node
	if err := yaml.Unmarshal(output.Bytes(), &report); err != nil {
		t.Fatalf("comparison report is not YAML: %q: %v", output.String(), err)
	}
	changes := field(report.Content[0], "changes")
	greeting := field(changes, "greeting")
	if greeting == nil || greeting.Value != "Goodbye" {
		t.Fatalf("fixture comparison report = %q", output.String())
	}

	output.Reset()
	outcome = app.Execute(context.Background(), []string{"config", "diff", "--config", "fixtures/before.yml", "--against-config", "fixtures/before.yml"}, commandkit.Streams{Out: &output, Err: io.Discard})
	if outcome.Kind != commandkit.OutcomeSuccess {
		t.Fatalf("equal fixture comparison outcome = %#v", outcome)
	}
	if reportNode, err := decodeReport(output.Bytes()); err != nil || len(field(reportNode, "additions").Content) != 0 || len(field(reportNode, "changes").Content) != 0 || len(field(reportNode, "deletions").Content) != 0 {
		t.Fatalf("equal fixture report = %q, decode error %v", output.String(), err)
	}

	output.Reset()
	outcome = app.Execute(context.Background(), []string{"config", "show"}, commandkit.Streams{Out: &output, Err: io.Discard})
	if outcome.Kind != commandkit.OutcomeSuccess || output.String() != "greeting: Hello\n" {
		t.Fatalf("default show outcome/output = %#v / %q", outcome, output.String())
	}

	output.Reset()
	outcome = app.Execute(context.Background(), []string{"greet"}, commandkit.Streams{Out: &output, Err: io.Discard})
	if outcome.Kind != commandkit.OutcomeSuccess || len(output.String()) == 0 || output.String()[:5] != "Hello" {
		t.Fatalf("default greeting outcome/output = %#v / %q", outcome, output.String())
	}
}

func TestSimpleLoaderDoesNotReplaceExplicitEmptyConfiguration(t *testing.T) {
	_, err := loadAppConfiguration(context.Background(), ckconfig.Selection{Config: commandkit.Supplied[string]{Set: true}})
	if err == nil {
		t.Fatal("explicit empty configuration fell back to the default source")
	}
}

func field(mapping *yaml.Node, name string) *yaml.Node {
	if mapping == nil || mapping.Kind != yaml.MappingNode {
		return nil
	}
	for index := 0; index+1 < len(mapping.Content); index += 2 {
		if mapping.Content[index].Value == name {
			return mapping.Content[index+1]
		}
	}
	return nil
}

func decodeReport(data []byte) (*yaml.Node, error) {
	var document yaml.Node
	if err := yaml.Unmarshal(data, &document); err != nil {
		return nil, err
	}
	return document.Content[0], nil
}