package usecase

import (
	"context"
	"errors"
	"testing"

	"gitea.maximumdirect.net/eric/promptkit/internal/domain"
)

type outputContractTestCollaborators struct {
	artifacts *fakeArtifactReader
	renderer  *fakeRenderer
	llm       *fakeLLM
	validator *recordingValidationPreparer
	admitter  *fakeRunAdmitter
}

func newOutputContractTestRunner() (*Runner, outputContractTestCollaborators) {
	collaborators := outputContractTestCollaborators{
		artifacts: defaultArtifactReader(),
		renderer:  defaultRenderer(),
		llm:       &fakeLLM{forbid: true},
		validator: &recordingValidationPreparer{plan: &recordingPreparedValidation{}},
		admitter:  &fakeRunAdmitter{},
	}
	return NewRunner(
		&fakePromptRepo{def: promptDef(domain.FormatText, domain.ValidationNone, 0)},
		&fakeExecutionProfileRepo{profiles: map[string]*domain.ExecutionProfile{"exec": defaultExecutionProfile()}},
		nil,
		collaborators.artifacts,
		collaborators.renderer,
		collaborators.llm,
		collaborators.validator,
		collaborators.admitter,
	), collaborators
}

func TestRunnerPreparationNormalizesOutputContractConsistently(t *testing.T) {
	tests := []struct {
		name     string
		override domain.OutputContract
		want     domain.OutputContract
	}{
		{
			name:     "empty replacement format defaults to text",
			override: domain.OutputContract{ValidationMode: domain.ValidationNone},
			want:     domain.OutputContract{Format: domain.FormatText, ValidationMode: domain.ValidationNone},
		},
		{
			name:     "markdown basic replacement",
			override: domain.OutputContract{Format: domain.FormatMarkdown, ValidationMode: domain.ValidationBasic},
			want:     domain.OutputContract{Format: domain.FormatMarkdown, ValidationMode: domain.ValidationBasic},
		},
		{
			name: "json replacement preserves non-schema fields",
			override: domain.OutputContract{
				Format:         domain.FormatJSON,
				ValidationMode: domain.ValidationJSON,
				SchemaPath:     "ignored.json",
				RepairAttempts: 2,
			},
			want: domain.OutputContract{
				Format:         domain.FormatJSON,
				ValidationMode: domain.ValidationJSON,
				SchemaPath:     "ignored.json",
				RepairAttempts: 2,
			},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			runner, _ := newOutputContractTestRunner()
			req := domain.RunRequest{
				PromptID:   "p",
				ProfileID:  "exec",
				Inputs:     singleInputRef(),
				Validation: &tt.override,
			}

			prepared, err := runner.Prepare(context.Background(), req)
			if err != nil {
				t.Fatalf("prepare: %v", err)
			}
			preparedExecution, err := runner.PrepareExecution(context.Background(), req)
			if err != nil {
				t.Fatalf("prepare execution: %v", err)
			}
			details := preparedExecution.Details()
			if details == nil {
				t.Fatal("prepared execution returned nil details")
			}
			if prepared.OutputContract != tt.want || details.OutputContract != tt.want {
				t.Fatalf("output contracts = (%+v, %+v), want %+v", prepared.OutputContract, details.OutputContract, tt.want)
			}
		})
	}
}

func TestRunnerPreparationRejectsInvalidOutputContractsBeforeCompletion(t *testing.T) {
	tests := []struct {
		name     string
		override domain.OutputContract
	}{
		{name: "unsupported format", override: domain.OutputContract{Format: "binary", ValidationMode: domain.ValidationNone}},
		{name: "empty validation mode", override: domain.OutputContract{Format: domain.FormatText}},
		{name: "negative repair attempts", override: domain.OutputContract{Format: domain.FormatText, ValidationMode: domain.ValidationNone, RepairAttempts: -1}},
		{name: "json schema without path", override: domain.OutputContract{Format: domain.FormatJSON, ValidationMode: domain.ValidationJSONSchema}},
	}

	for _, tt := range tests {
		for _, operation := range []string{"Prepare", "PrepareExecution"} {
			t.Run(tt.name+"/"+operation, func(t *testing.T) {
				runner, collaborators := newOutputContractTestRunner()
				req := domain.RunRequest{
					PromptID:   "p",
					ProfileID:  "exec",
					Inputs:     singleInputRef(),
					Validation: &tt.override,
				}

				var err error
				switch operation {
				case "Prepare":
					var prepared *domain.PreparedRun
					prepared, err = runner.Prepare(context.Background(), req)
					if prepared != nil {
						t.Fatalf("expected no partial prepared run, got %+v", prepared)
					}
				case "PrepareExecution":
					var prepared *PreparedExecution
					prepared, err = runner.PrepareExecution(context.Background(), req)
					if prepared != nil {
						t.Fatalf("expected no partial prepared execution, got %+v", prepared)
					}
				default:
					t.Fatalf("unknown operation %q", operation)
				}

				if !errors.Is(err, ErrInvalidRequest) {
					t.Fatalf("expected ErrInvalidRequest, got %v", err)
				}
				assertOutputContractCompletionSkipped(t, collaborators)
			})
		}
	}
}

func TestRunnerRunRejectsInvalidOutputContractBeforeAdmission(t *testing.T) {
	runner, collaborators := newOutputContractTestRunner()
	result, err := runner.Run(context.Background(), domain.RunRequest{
		PromptID:  "p",
		ProfileID: "exec",
		Inputs:    singleInputRef(),
		Validation: &domain.OutputContract{
			Format:         domain.OutputFormat("binary"),
			ValidationMode: domain.ValidationNone,
		},
	})
	if result != nil {
		t.Fatalf("expected no partial result, got %+v", result)
	}
	if !errors.Is(err, ErrInvalidRequest) {
		t.Fatalf("expected ErrInvalidRequest, got %v", err)
	}
	assertOutputContractCompletionSkipped(t, collaborators)
}

func assertOutputContractCompletionSkipped(t *testing.T, collaborators outputContractTestCollaborators) {
	t.Helper()
	if collaborators.artifacts.calls != 0 || collaborators.renderer.calls != 0 ||
		collaborators.validator.prepareCalls != 0 || collaborators.validator.directValidateCalls != 0 ||
		len(collaborators.admitter.backendIDs) != 0 || collaborators.llm.calls != 0 {
		t.Fatalf(
			"invalid output contract reached downstream work: artifacts=%d renderer=%d prepare_validation=%d validation=%d admissions=%d generation=%d",
			collaborators.artifacts.calls,
			collaborators.renderer.calls,
			collaborators.validator.prepareCalls,
			collaborators.validator.directValidateCalls,
			len(collaborators.admitter.backendIDs),
			collaborators.llm.calls,
		)
	}
}