package ckprompt

import (
	"bytes"
	"context"
	"errors"
	"io"
	"strings"
	"testing"

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

func TestSmokeTestFindingsDoNotChangeSuccessfulOutcome(t *testing.T) {
	falseValue := false
	app := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{
		SmokeTest: func(context.Context, SmokeRequest, struct{}, struct{}) (commandkit.Acquired[*promptkit.SmokeTestReport], error) {
			return commandkit.Acquired[*promptkit.SmokeTestReport]{Value: &promptkit.SmokeTestReport{
				Kind: promptkit.SmokeTestReachability, Supported: false, Applicable: nil, Completed: false,
				Facts: promptkit.SmokeTestFacts{EndpointReachable: &falseValue},
			}}, nil
		},
	}))
	var output bytes.Buffer
	outcome := app.Execute(context.Background(), []string{"promptkit", "test", "reachability"}, commandkit.Streams{Out: &output, Err: io.Discard})
	if outcome.Kind != commandkit.OutcomeSuccess || outcome.Cause != nil {
		t.Fatalf("false and unknown findings changed outcome: %#v", outcome)
	}
	var report struct {
		Supported  bool  `yaml:"supported"`
		Applicable *bool `yaml:"applicable"`
		Completed  bool  `yaml:"completed"`
		Facts      struct {
			EndpointReachable *bool `yaml:"endpoint_reachable"`
		} `yaml:"facts"`
	}
	if err := yaml.Unmarshal(output.Bytes(), &report); err != nil {
		t.Fatalf("decode smoke findings %q: %v", output.String(), err)
	}
	if report.Supported || report.Applicable != nil || report.Completed || report.Facts.EndpointReachable == nil || *report.Facts.EndpointReachable {
		t.Fatalf("native findings were not retained: %#v", report)
	}
}

func TestSmokeTestCancellationAfterAcquisitionStillDeliversReport(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	t.Cleanup(cancel)
	calls := 0
	app := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{
		SmokeTest: func(context.Context, SmokeRequest, struct{}, struct{}) (commandkit.Acquired[*promptkit.SmokeTestReport], error) {
			calls++
			cancel()
			return commandkit.Acquired[*promptkit.SmokeTestReport]{Value: &promptkit.SmokeTestReport{Kind: promptkit.SmokeTestAuthentication}}, nil
		},
	}))
	var output bytes.Buffer
	outcome := app.Execute(ctx, []string{"promptkit", "test", "authentication"}, commandkit.Streams{Out: &output, Err: io.Discard})
	if outcome.Kind != commandkit.OutcomeOperational || !errors.Is(outcome.Cause, context.Canceled) || calls != 1 || output.Len() == 0 {
		t.Fatalf("post-acquisition cancellation = (%#v, %q), calls=%d", outcome, output.String(), calls)
	}
}

func TestSmokeTestCancellationBeforeAcquisitionSkipsProvider(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	calls, stateCalls := 0, 0
	app := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{
		NewState: func() struct{} { stateCalls++; return struct{}{} },
		SmokeTest: func(context.Context, SmokeRequest, struct{}, struct{}) (commandkit.Acquired[*promptkit.SmokeTestReport], error) {
			calls++
			return commandkit.Acquired[*promptkit.SmokeTestReport]{Value: &promptkit.SmokeTestReport{}}, nil
		},
	}))
	var output bytes.Buffer
	outcome := app.Execute(ctx, []string{"promptkit", "test", "authentication"}, commandkit.Streams{Out: &output, Err: io.Discard})
	if outcome.Kind != commandkit.OutcomeOperational || !errors.Is(outcome.Cause, context.Canceled) || calls != 0 || stateCalls != 0 || output.Len() != 0 {
		t.Fatalf("pre-acquisition cancellation = (%#v, %q), calls/state=%d/%d", outcome, output.String(), calls, stateCalls)
	}
}

func TestSmokeTestEncodingAndWriterFailuresRetainOutcomeFields(t *testing.T) {
	operationErr := errors.New("native operation failed")
	diagnostic := commandkit.Diagnostic{Severity: commandkit.SeverityWarning, Write: func(writer io.Writer) error {
		_, err := io.WriteString(writer, "smoke warning\n")
		return err
	}}
	app := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{
		SmokeTest: func(context.Context, SmokeRequest, struct{}, struct{}) (commandkit.Acquired[*promptkit.SmokeTestReport], error) {
			return commandkit.Acquired[*promptkit.SmokeTestReport]{
				Value:       &promptkit.SmokeTestReport{Kind: promptkit.SmokeTestAuthentication},
				Diagnostics: []commandkit.Diagnostic{diagnostic},
			}, operationErr
		},
	}))
	writeErr := errors.New("smoke report writer failed")
	for _, test := range []struct {
		name   string
		writer io.Writer
		want   error
	}{
		{name: "writer error", writer: partialReportWriter{err: writeErr}, want: writeErr},
		{name: "short write", writer: partialReportWriter{}, want: io.ErrShortWrite},
	} {
		t.Run(test.name, func(t *testing.T) {
			var diagnosticOutput bytes.Buffer
			outcome := app.Execute(context.Background(), []string{"promptkit", "test", "authentication", "--verbose"}, commandkit.Streams{Out: test.writer, Err: &diagnosticOutput})
			warningIndex := strings.Index(diagnosticOutput.String(), "smoke warning")
			if outcome.Kind != commandkit.OutcomeOperational || !errors.Is(outcome.Cause, operationErr) || !errors.Is(outcome.Presentation.Output.WriteError, test.want) || outcome.Presentation.Output.State != commandkit.DeliveryIncomplete || outcome.Presentation.Diagnostics.State != commandkit.DeliveryComplete || warningIndex < 0 || strings.Contains(diagnosticOutput.String(), operationErr.Error()) {
				t.Fatalf("report delivery = %#v, diagnostics=%q", outcome, diagnosticOutput.String())
			}
		})
	}

	diagnosticErr := errors.New("smoke diagnostic writer failed")
	var output bytes.Buffer
	outcome := app.Execute(context.Background(), []string{"promptkit", "test", "authentication", "--verbose"}, commandkit.Streams{Out: &output, Err: partialReportWriter{err: diagnosticErr}})
	if outcome.Kind != commandkit.OutcomeOperational || !errors.Is(outcome.Cause, operationErr) || !errors.Is(outcome.Presentation.Diagnostics.WriteError, diagnosticErr) || outcome.Presentation.Diagnostics.State != commandkit.DeliveryIncomplete || output.Len() == 0 {
		t.Fatalf("diagnostic delivery = (%#v, %q)", outcome, output.String())
	}

	encodeApp := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{
		SmokeTest: func(context.Context, SmokeRequest, struct{}, struct{}) (commandkit.Acquired[*promptkit.SmokeTestReport], error) {
			return commandkit.Acquired[*promptkit.SmokeTestReport]{Value: &promptkit.SmokeTestReport{
				Target: promptkit.SmokeTestTarget{EffectiveSettings: promptkit.ExecutionTarget{ExtraParams: map[string]any{"unsupported": func() {}}}},
			}}, nil
		},
	}))
	output.Reset()
	outcome = encodeApp.Execute(context.Background(), []string{"promptkit", "test", "authentication"}, commandkit.Streams{Out: &output, Err: io.Discard})
	if outcome.Kind != commandkit.OutcomeOperational || outcome.Cause != nil || outcome.Presentation.Output.RenderError == nil || output.Len() != 0 {
		t.Fatalf("encoding failure = (%#v, %q)", outcome, output.String())
	}
}

type smokeTypedError struct{ text string }

func (err *smokeTypedError) Error() string { return err.text }

func TestSmokeAggregatePreservesMultipleTypedCauses(t *testing.T) {
	firstErr := &smokeTypedError{text: "reachability failed"}
	secondErr := &smokeTypedError{text: ""}
	app := newPromptTestApp(t, Command(Suite[struct{}, struct{}]{
		SmokeTest: func(_ context.Context, request SmokeRequest, _ struct{}, _ struct{}) (commandkit.Acquired[*promptkit.SmokeTestReport], error) {
			var err error
			switch request.Request.Kind {
			case promptkit.SmokeTestReachability:
				err = firstErr
			case promptkit.SmokeTestAuthentication:
				err = secondErr
			}
			acquired := commandkit.Acquired[*promptkit.SmokeTestReport]{Value: &promptkit.SmokeTestReport{Kind: request.Request.Kind}}
			if err != nil {
				acquired.Explanation = commandkit.Explanation{Message: string(request.Request.Kind) + " native context"}
			}
			return acquired, err
		},
	}))
	var output, diagnosticOutput bytes.Buffer
	outcome := app.Execute(context.Background(), []string{"promptkit", "test", "all"}, commandkit.Streams{Out: &output, Err: &diagnosticOutput})
	var retained *smokeTypedError
	if outcome.Kind != commandkit.OutcomeOperational || !errors.Is(outcome.Cause, firstErr) || !errors.Is(outcome.Cause, secondErr) || !errors.As(outcome.Cause, &retained) || retained != firstErr {
		t.Fatalf("joined aggregate errors lost identity: %#v, retained=%#v", outcome, retained)
	}
	firstContext := strings.Index(diagnosticOutput.String(), "reachability native context")
	secondContext := strings.Index(diagnosticOutput.String(), "authentication native context")
	if firstContext < 0 || secondContext < 0 || firstContext >= secondContext {
		t.Fatalf("aggregate native explanations were not retained in order: %q", diagnosticOutput.String())
	}
	var document struct {
		Tests []struct {
			Kind  string  `yaml:"kind"`
			Error *string `yaml:"error"`
		} `yaml:"tests"`
	}
	if err := yaml.Unmarshal(output.Bytes(), &document); err != nil {
		t.Fatalf("decode aggregate errors %q: %v", output.String(), err)
	}
	if len(document.Tests) != 4 || document.Tests[0].Kind != string(promptkit.SmokeTestReachability) || document.Tests[0].Error == nil || *document.Tests[0].Error != firstErr.Error() || document.Tests[1].Kind != string(promptkit.SmokeTestAuthentication) || document.Tests[1].Error == nil || *document.Tests[1].Error != secondErr.Error() || document.Tests[2].Error != nil || document.Tests[3].Error != nil {
		t.Fatalf("aggregate error entries = %#v", document.Tests)
	}
}