package briefing

import (
	"encoding/json"
	"errors"
	"strings"
	"testing"

	"gitea.maximumdirect.net/eric/weatherreporter/internal/facts"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/weatherdata"
)

func TestDefaultModuleRegistryValidatesReportDefaults(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	for _, definition := range report.DefaultRegistry().All() {
		if err := registry.ValidateComposition(definition.ID, definition.Modules); err != nil {
			t.Fatalf("ValidateComposition(%s) error = %v", definition.ID, err)
		}
		for _, item := range definition.Modules {
			moduleDefinition, err := registry.Lookup(item.ID)
			if err != nil {
				t.Fatalf("Lookup(%s) error = %v", item.ID, err)
			}
			if moduleDefinition.Builder == nil {
				t.Fatalf("report %s module %s has no builder", definition.ID, item.ID)
			}
		}
	}
}

func TestFactRequirementVocabularyMatchesModuleDefinitions(t *testing.T) {
	vocabulary := make(map[string]factRequirement, len(factRequirementVocabulary))
	for _, requirement := range factRequirementVocabulary {
		if requirement.identity == "" {
			t.Fatal("fact requirement identity is empty")
		}
		if requirement.category != collectedFactRequirement && requirement.category != derivedFactRequirement {
			t.Fatalf("fact requirement %q category = %q, want collected or derived", requirement.identity, requirement.category)
		}
		if _, exists := vocabulary[requirement.identity]; exists {
			t.Fatalf("duplicate fact requirement %q", requirement.identity)
		}
		vocabulary[requirement.identity] = requirement
	}

	used := map[factRequirement]struct{}{}
	for _, definition := range defaultModuleDefinitions() {
		for _, requirement := range definition.RequiredCollected {
			assertFactRequirementCategory(t, vocabulary, used, definition.ID, requirement, collectedFactRequirement)
		}
		for _, requirement := range definition.RequiredDerived {
			assertFactRequirementCategory(t, vocabulary, used, definition.ID, requirement, derivedFactRequirement)
		}
	}
	for _, requirement := range factRequirementVocabulary {
		if _, ok := used[requirement]; !ok {
			t.Fatalf("fact requirement %q is not used by a module definition", requirement.identity)
		}
	}
}

func assertFactRequirementCategory(t *testing.T, vocabulary map[string]factRequirement, used map[factRequirement]struct{}, moduleID module.ID, requirement factRequirement, want factRequirementCategory) {
	t.Helper()
	descriptor, ok := vocabulary[requirement.identity]
	if !ok {
		t.Fatalf("module %q uses unknown fact requirement %q", moduleID, requirement.identity)
	}
	if descriptor != requirement {
		t.Fatalf("module %q requirement %q does not use the vocabulary descriptor", moduleID, requirement.identity)
	}
	if requirement.category != want {
		t.Fatalf("module %q requirement %q category = %q, want %q", moduleID, requirement.identity, requirement.category, want)
	}
	used[requirement] = struct{}{}
}

func TestDefaultReportModulesBuildSnapshots(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	for _, definition := range report.DefaultRegistry().All() {
		t.Run(string(definition.ID), func(t *testing.T) {
			ctx := derivedModuleContext(definition.ID)
			var outputs []module.Output
			for _, item := range definition.Modules {
				output, err := registry.BuildModule(ctx, item)
				if err != nil {
					t.Fatalf("BuildModule(%s) error = %v", item.ID, err)
				}
				if output != nil {
					if output.DataPackageValue() == nil {
						t.Fatalf("BuildModule(%s) data package value = nil", item.ID)
					}
					outputs = append(outputs, *output)
				}
			}
			snapshot, err := module.NewSnapshot(outputs)
			if err != nil {
				t.Fatalf("NewSnapshot() error = %v", err)
			}
			if len(snapshot.Outputs) == 0 {
				t.Fatal("snapshot outputs = 0, want default report modules")
			}
		})
	}
}

func TestDefaultModuleDefinitionsDeclarePromptExportPolicy(t *testing.T) {
	customExporters := map[module.ID]struct{}{
		module.CurrentConditions:       {},
		module.HourlyForecast:          {},
		module.DerivedDaypartSummaries: {},
	}
	passThroughExporters := map[module.ID]struct{}{
		module.Metadata:                {},
		module.NarrativeForecast:       {},
		module.DerivedDailySummary:     {},
		module.PrecipTiming:            {},
		module.AlertDigest:             {},
		module.SPCConvectiveOutlooks:   {},
		module.AreaForecastDiscussion:  {},
		module.SPCConvectiveDiscussion: {},
		module.WeatherStory:            {},
		module.OutdoorWindows:          {},
		module.TodayPlanning:           {},
		module.TomorrowPlanning:        {},
		module.DailyPlanning:           {},
	}

	for _, definition := range defaultModuleDefinitions() {
		_, custom := customExporters[definition.ID]
		_, passThrough := passThroughExporters[definition.ID]
		if custom == passThrough {
			t.Fatalf("module %q exporter policy custom=%v passThrough=%v, want exactly one policy", definition.ID, custom, passThrough)
		}
		if custom && definition.PromptExporter == nil {
			t.Fatalf("module %q PromptExporter = nil, want custom prompt exporter", definition.ID)
		}
		if passThrough && definition.PromptExporter != nil {
			t.Fatalf("module %q PromptExporter is set, want default pass-through", definition.ID)
		}
	}
}

func TestModuleRegistryAddsPassThroughPromptValue(t *testing.T) {
	registry, err := NewModuleRegistry([]ModuleDefinition{
		{
			ID:         module.Metadata,
			StanzaName: "metadata",
			Builder: func(ModuleContext, any) (*module.Output, error) {
				return &module.Output{
					ID:         module.Metadata,
					StanzaName: "metadata",
					Value:      testRegistryValue{Message: "rich"},
				}, nil
			},
		},
	})
	if err != nil {
		t.Fatalf("NewModuleRegistry() error = %v", err)
	}

	output, err := registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
	if err != nil {
		t.Fatalf("BuildModule() error = %v", err)
	}
	if output == nil {
		t.Fatal("BuildModule() output = nil, want output")
	}
	if output.PromptValue != output.Value {
		t.Fatalf("PromptValue = %#v, want pass-through rich value %#v", output.PromptValue, output.Value)
	}
	if output.DataPackageValue() != output.Value {
		t.Fatalf("DataPackageValue() = %#v, want rich value", output.DataPackageValue())
	}
}

func TestModuleRegistryAddsCustomPromptValue(t *testing.T) {
	registry, err := NewModuleRegistry([]ModuleDefinition{
		{
			ID:         module.Metadata,
			StanzaName: "metadata",
			Builder: func(ModuleContext, any) (*module.Output, error) {
				return &module.Output{
					ID:         module.Metadata,
					StanzaName: "metadata",
					Value:      testRegistryValue{Message: "rich"},
				}, nil
			},
			PromptExporter: func(value any) (any, error) {
				rich, ok := value.(testRegistryValue)
				if !ok {
					return nil, errors.New("unexpected rich value type")
				}
				return testRegistryValue{Message: rich.Message + " prompt"}, nil
			},
		},
	})
	if err != nil {
		t.Fatalf("NewModuleRegistry() error = %v", err)
	}

	output, err := registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
	if err != nil {
		t.Fatalf("BuildModule() error = %v", err)
	}
	got, ok := output.PromptValue.(testRegistryValue)
	if !ok {
		t.Fatalf("PromptValue type = %T, want testRegistryValue", output.PromptValue)
	}
	if got.Message != "rich prompt" {
		t.Fatalf("PromptValue = %#v, want custom prompt value", got)
	}
	if output.DataPackageValue() != output.PromptValue {
		t.Fatalf("DataPackageValue() = %#v, want custom prompt value", output.DataPackageValue())
	}
	if output.Value.(testRegistryValue).Message != "rich" {
		t.Fatalf("Value = %#v, want rich value unchanged", output.Value)
	}
}

func TestModuleRegistryWrapsPromptExporterErrors(t *testing.T) {
	registry, err := NewModuleRegistry([]ModuleDefinition{
		{
			ID:         module.Metadata,
			StanzaName: "metadata",
			Builder: func(ModuleContext, any) (*module.Output, error) {
				return &module.Output{ID: module.Metadata, StanzaName: "metadata", Value: testRegistryValue{Message: "rich"}}, nil
			},
			PromptExporter: func(any) (any, error) {
				return nil, errors.New("unsupported value")
			},
		},
	})
	if err != nil {
		t.Fatalf("NewModuleRegistry() error = %v", err)
	}

	_, err = registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
	if err == nil ||
		!strings.Contains(err.Error(), `module "metadata" stanza "metadata" prompt export`) ||
		!strings.Contains(err.Error(), "unsupported value") {
		t.Fatalf("BuildModule() error = %v, want wrapped exporter error", err)
	}
}

func TestModuleRegistryValidatesOutputBeforePromptExport(t *testing.T) {
	called := false
	registry, err := NewModuleRegistry([]ModuleDefinition{
		{
			ID:         module.Metadata,
			StanzaName: "metadata",
			Builder: func(ModuleContext, any) (*module.Output, error) {
				return &module.Output{ID: module.CurrentConditions, StanzaName: "metadata", Value: testRegistryValue{Message: "rich"}}, nil
			},
			PromptExporter: func(any) (any, error) {
				called = true
				return testRegistryValue{Message: "prompt"}, nil
			},
		},
	})
	if err != nil {
		t.Fatalf("NewModuleRegistry() error = %v", err)
	}

	_, err = registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
	if err == nil || !strings.Contains(err.Error(), `module "metadata" produced output id "current_conditions"`) {
		t.Fatalf("BuildModule() error = %v, want output id validation error", err)
	}
	if called {
		t.Fatal("PromptExporter called before output validation")
	}
}

func TestModuleRegistryPromptValueIsNotPersistedInSnapshotJSON(t *testing.T) {
	registry, err := NewModuleRegistry([]ModuleDefinition{
		{
			ID:         module.Metadata,
			StanzaName: "metadata",
			Builder: func(ModuleContext, any) (*module.Output, error) {
				return &module.Output{ID: module.Metadata, StanzaName: "metadata", Value: testRegistryValue{Message: "rich"}}, nil
			},
			PromptExporter: func(any) (any, error) {
				return testRegistryValue{Message: "prompt-only"}, nil
			},
		},
	})
	if err != nil {
		t.Fatalf("NewModuleRegistry() error = %v", err)
	}
	output, err := registry.BuildModule(testRegistryModuleContext(), module.ConfigItem{ID: module.Metadata})
	if err != nil {
		t.Fatalf("BuildModule() error = %v", err)
	}
	snapshot, err := module.NewSnapshot([]module.Output{*output})
	if err != nil {
		t.Fatalf("NewSnapshot() error = %v", err)
	}
	data, err := json.Marshal(snapshot)
	if err != nil {
		t.Fatalf("Marshal() error = %v", err)
	}
	text := string(data)
	if !strings.Contains(text, `"message":"rich"`) {
		t.Fatalf("snapshot JSON missing rich value: %s", text)
	}
	if strings.Contains(text, "prompt-only") || strings.Contains(text, "promptValue") || strings.Contains(text, "PromptValue") {
		t.Fatalf("snapshot JSON includes runtime-only prompt value: %s", text)
	}
}

func TestDefaultAreaForecastDiscussionModuleOptions(t *testing.T) {
	tests := []struct {
		id           report.ID
		wantSections string
	}{
		{id: report.Daily, wantSections: "long_term"},
		{id: report.Hourly, wantSections: "key_messages,short_term"},
	}

	registry := report.DefaultRegistry()
	for _, tt := range tests {
		t.Run(string(tt.id), func(t *testing.T) {
			definition := registry.MustLookup(tt.id)
			var found bool
			for _, item := range definition.Modules {
				if item.ID != module.AreaForecastDiscussion {
					continue
				}
				found = true
				options, ok := item.Options.(module.AreaForecastDiscussionOptions)
				if !ok {
					t.Fatalf("AFD options type = %T, want AreaForecastDiscussionOptions", item.Options)
				}
				if strings.Join(options.Sections, ",") != tt.wantSections {
					t.Fatalf("AFD sections = %#v, want %s", options.Sections, tt.wantSections)
				}
			}
			if !found {
				t.Fatal("default modules missing area_forecast_discussion")
			}
		})
	}

	for _, id := range []report.ID{report.Today, report.Tomorrow} {
		t.Run(string(id), func(t *testing.T) {
			definition := registry.MustLookup(id)
			var found bool
			for _, item := range definition.Modules {
				if item.ID != module.AreaForecastDiscussion {
					continue
				}
				found = true
				if item.Options != nil {
					t.Fatalf("AFD options = %#v, want default all sections", item.Options)
				}
			}
			if !found {
				t.Fatal("default modules missing area_forecast_discussion")
			}
		})
	}
}

func TestModuleRegistryRejectsUnknownModule(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	err := registry.ValidateComposition(report.Daily, []module.ConfigItem{{ID: module.ID("unknown")}})
	if err == nil || !strings.Contains(err.Error(), `unknown module "unknown"`) {
		t.Fatalf("error = %v, want unknown module", err)
	}
}

func TestModuleRegistryRejectsDuplicateModuleIDs(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	err := registry.ValidateComposition(report.Daily, []module.ConfigItem{
		{ID: module.Metadata},
		{ID: module.Metadata},
	})
	if err == nil || !strings.Contains(err.Error(), `duplicate module "metadata"`) {
		t.Fatalf("error = %v, want duplicate module", err)
	}
}

func TestModuleRegistryRejectsDuplicateStanzaNames(t *testing.T) {
	_, err := NewModuleRegistry([]ModuleDefinition{
		{ID: module.Metadata, StanzaName: "metadata", DefaultOptions: module.MetadataOptions{}, Builder: noopModuleBuilder},
		{ID: module.CurrentConditions, StanzaName: "metadata", DefaultOptions: module.CurrentConditionsOptions{}, Builder: noopModuleBuilder},
	})
	if err == nil || !strings.Contains(err.Error(), `duplicate stanza name "metadata"`) {
		t.Fatalf("error = %v, want duplicate stanza name", err)
	}
}

func TestModuleRegistryRejectsIncompatibleReports(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	err := registry.ValidateComposition(report.Daily, []module.ConfigItem{{ID: module.TomorrowPlanning}})
	if err == nil || !strings.Contains(err.Error(), `module "tomorrow_planning" is not compatible with report "daily"`) {
		t.Fatalf("error = %v, want incompatible report", err)
	}
}

func TestModuleRegistryValidatesTodayPlanningSupport(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	if err := registry.ValidateComposition(report.Today, []module.ConfigItem{{ID: module.TodayPlanning}}); err != nil {
		t.Fatalf("ValidateComposition(today) error = %v", err)
	}
	for _, id := range []report.ID{report.Tomorrow, report.Daily} {
		t.Run(string(id), func(t *testing.T) {
			err := registry.ValidateComposition(id, []module.ConfigItem{{ID: module.TodayPlanning}})
			if err == nil || !strings.Contains(err.Error(), `module "today_planning" is not compatible with report`) {
				t.Fatalf("ValidateComposition(%s) error = %v, want incompatible report", id, err)
			}
		})
	}
}

func TestModuleRegistryValidatesDailyPlanningSupport(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	if err := registry.ValidateComposition(report.Daily, []module.ConfigItem{{ID: module.DailyPlanning}}); err != nil {
		t.Fatalf("ValidateComposition(daily) error = %v", err)
	}
	for _, id := range []report.ID{report.Today, report.Tomorrow, report.Hourly} {
		t.Run(string(id), func(t *testing.T) {
			err := registry.ValidateComposition(id, []module.ConfigItem{{ID: module.DailyPlanning}})
			if err == nil || !strings.Contains(err.Error(), `module "daily_planning" is not compatible with report`) {
				t.Fatalf("ValidateComposition(%s) error = %v, want incompatible report", id, err)
			}
		})
	}
}

func TestModuleRegistrySupportsTodayEligibleModules(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	err := registry.ValidateComposition(report.Today, []module.ConfigItem{
		{ID: module.Metadata},
		{ID: module.CurrentConditions},
		{ID: module.NarrativeForecast},
		{ID: module.HourlyForecast},
		{ID: module.DerivedDailySummary},
		{ID: module.DerivedDaypartSummaries},
		{ID: module.PrecipTiming},
		{ID: module.AlertDigest},
		{ID: module.SPCConvectiveOutlooks},
		{ID: module.AreaForecastDiscussion},
		{ID: module.SPCConvectiveDiscussion},
		{ID: module.WeatherStory},
		{ID: module.OutdoorWindows},
	})
	if err != nil {
		t.Fatalf("ValidateComposition(today eligible modules) error = %v", err)
	}
}

func TestModuleRegistryRejectsHourlyIncompatibleModules(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	for _, id := range []module.ID{
		module.NarrativeForecast,
		module.DerivedDailySummary,
		module.DerivedDaypartSummaries,
		module.OutdoorWindows,
		module.TodayPlanning,
		module.TomorrowPlanning,
		module.DailyPlanning,
	} {
		t.Run(string(id), func(t *testing.T) {
			err := registry.ValidateComposition(report.Hourly, []module.ConfigItem{{ID: id}})
			if err == nil || !strings.Contains(err.Error(), `not compatible with report "hourly"`) {
				t.Fatalf("ValidateComposition() error = %v, want incompatible hourly module", err)
			}
		})
	}
}

func TestModuleRegistryRejectsDefinitionsWithoutBuilders(t *testing.T) {
	_, err := NewModuleRegistry([]ModuleDefinition{
		{ID: module.Metadata, StanzaName: "metadata", DefaultOptions: module.MetadataOptions{}},
	})
	if err == nil || !strings.Contains(err.Error(), `module "metadata" has no builder`) {
		t.Fatalf("error = %v, want missing builder", err)
	}
}

func TestModuleRegistryRejectsUnsupportedMissingDataWarn(t *testing.T) {
	_, err := NewModuleRegistry([]ModuleDefinition{
		{ID: module.Metadata, StanzaName: "metadata", DefaultOptions: module.MetadataOptions{}, MissingData: module.MissingDataWarn, Builder: noopModuleBuilder},
	})
	if err == nil || !strings.Contains(err.Error(), `unsupported missing data behavior`) {
		t.Fatalf("error = %v, want unsupported missing-data behavior", err)
	}
}

func TestModuleRegistryRejectsInvalidOptionShapes(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	err := registry.ValidateComposition(report.Daily, []module.ConfigItem{
		{ID: module.Metadata, Options: module.CurrentConditionsOptions{}},
	})
	if err == nil || !strings.Contains(err.Error(), `module "metadata" options have type module.CurrentConditionsOptions, want module.MetadataOptions`) {
		t.Fatalf("error = %v, want invalid option shape", err)
	}
}

func TestModuleRegistryAcceptsTypedOptions(t *testing.T) {
	registry := MustDefaultModuleRegistry()
	err := registry.ValidateComposition(report.Daily, []module.ConfigItem{
		{ID: module.Metadata, Options: module.MetadataOptions{}},
		{ID: module.CurrentConditions, Options: &module.CurrentConditionsOptions{}},
		{ID: module.AreaForecastDiscussion, Options: &module.AreaForecastDiscussionOptions{Sections: []string{"short_term"}}},
	})
	if err != nil {
		t.Fatalf("ValidateComposition() error = %v", err)
	}
}

func TestSPCConvectiveOutlookCollectedRequirementAvailability(t *testing.T) {
	ctx := ModuleContext{}
	if collectedFactAvailable(spcOutlooksRequirement, ctx) {
		t.Fatal("collectedFactAvailable() = true, want false without source")
	}

	ctx.Collected = facts.CollectedFacts{SPCConvectiveOutlooks: &weatherdata.ConvectiveOutlookRun{}}
	if !collectedFactAvailable(spcOutlooksRequirement, ctx) {
		t.Fatal("collectedFactAvailable() = false, want true with checked source")
	}
}

func TestSPCConvectiveOutlookDerivedRequirementAvailability(t *testing.T) {
	ctx := ModuleContext{}
	if derivedFactAvailable(spcDerivedOutlooksRequirement, ctx) {
		t.Fatal("derivedFactAvailable() = true, want false without derived outlooks")
	}

	ctx.Derived = facts.DerivedFacts{SPCConvectiveOutlooks: []weatherdata.ConvectiveOutlook{}}
	if !derivedFactAvailable(spcDerivedOutlooksRequirement, ctx) {
		t.Fatal("derivedFactAvailable() = false, want true for checked empty derived outlooks")
	}
}

func noopModuleBuilder(ModuleContext, any) (*module.Output, error) {
	return &module.Output{ID: module.Metadata, StanzaName: "metadata", Value: struct{}{}}, nil
}

type testRegistryValue struct {
	Message string `json:"message"`
}

func testRegistryModuleContext() ModuleContext {
	return ModuleContext{
		Resolved: report.Resolved{
			Definition: report.DefaultRegistry().MustLookup(report.Daily),
		},
	}
}