package app

import (
	"bytes"
	"reflect"
	"testing"

	"gitea.maximumdirect.net/eric/weatherreporter/internal/briefing"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/collect"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/generatedtext"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/module"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
	"gitea.maximumdirect.net/eric/weatherreporter/internal/weatherdata"
)

func TestPrepareReportBuildsImmutableDeterministicInputs(t *testing.T) {
	cfg := generationConfig()
	bundle := generationBundle(t)
	resolved, err := ResolveGenerate(GenerateRequest{
		Config: cfg, Report: ReportDaily,
		Date: generationTime("2026-05-29T12:00:00-05:00"), Now: generationTime("2026-05-29T08:30:00-05:00"),
	}, generationTime("2026-05-29T08:30:00-05:00"))
	if err != nil {
		t.Fatalf("ResolveGenerate() error = %v", err)
	}

	request := prepareReportRequest{Config: cfg, Resolved: resolved, Collection: collect.Result{Bundle: &bundle}, handler: preparedHandler(t, resolved)}
	prepared, err := prepareReport(request)
	if err != nil {
		t.Fatalf("prepareReport() error = %v", err)
	}
	repeated, err := prepareReport(request)
	if err != nil {
		t.Fatalf("second prepareReport() error = %v", err)
	}
	if len(prepared.dataPackage) == 0 || !bytes.Equal(prepared.dataPackage, repeated.dataPackage) || !reflect.DeepEqual(prepared.identity, repeated.identity) {
		t.Fatalf("prepared package and identity are not deterministic: %q/%#v", prepared.dataPackage, prepared.identity)
	}

	originalDataPackage := append([]byte(nil), prepared.dataPackage...)
	originalIdentity := prepared.identity
	originalDerived := prepared.derived
	originalWarnings := append([]weatherdata.SourceWarning(nil), prepared.sourceWarnings...)
	identity, snapshot, derived, err := prepared.renderInputs()
	if err != nil {
		t.Fatalf("renderInputs() error = %v", err)
	}
	identity.SourceWarnings = append(identity.SourceWarnings, weatherdata.SourceWarning{Source: "test", Message: "consumer mutation"})
	snapshot.Outputs = nil
	derived.PrecipTiming.ThunderMentioned = false
	bundle.Hourly.Periods[0].TextDescription = "mutated after preparation"
	bundle.Warnings = append(bundle.Warnings, weatherdata.SourceWarning{Source: "test", Message: "mutated warning"})
	if len(bundle.Sources) > 0 {
		if bundle.Sources[0].Query == nil {
			bundle.Sources[0].Query = map[string]string{}
		}
		bundle.Sources[0].Query["mutated"] = "true"
	}

	if !bytes.Equal(prepared.dataPackage, originalDataPackage) || !reflect.DeepEqual(prepared.identity, originalIdentity) || !reflect.DeepEqual(prepared.derived, originalDerived) || !reflect.DeepEqual(prepared.sourceWarnings, originalWarnings) {
		t.Fatalf("prepared values changed after caller mutation: %#v", prepared)
	}
	if len(prepared.moduleSnapshot.Outputs) == 0 {
		t.Fatal("prepared report values retain consumer mutation")
	}
}

func TestPrepareReportProjectsPreparedIdentity(t *testing.T) {
	cfg := generationConfig()
	bundle := generationBundle(t)
	resolved, err := ResolveGenerate(GenerateRequest{
		Config: cfg, Report: ReportDaily,
		Date: generationTime("2026-05-29T12:00:00-05:00"), Now: generationTime("2026-05-29T08:30:00-05:00"),
	}, generationTime("2026-05-29T08:30:00-05:00"))
	if err != nil {
		t.Fatalf("ResolveGenerate() error = %v", err)
	}
	prepared, err := prepareReport(prepareReportRequest{Config: cfg, Resolved: resolved, Collection: collect.Result{Bundle: &bundle}, handler: preparedHandler(t, resolved)})
	if err != nil {
		t.Fatalf("prepareReport() error = %v", err)
	}

	identity := prepared.identity
	renderIdentity, _, _, err := prepared.renderInputs()
	if err != nil {
		t.Fatalf("renderInputs() error = %v", err)
	}
	if !reflect.DeepEqual(renderIdentity, identity) {
		t.Fatalf("render identity = %#v, want %#v", renderIdentity, identity)
	}
	prompt := promptMetadata(identity)
	if prompt.RunID != identity.RunID || prompt.ReportID != identity.ReportID || prompt.Variant != identity.Variant || prompt.PromptID != identity.PromptID || !prompt.GeneratedAt.Equal(identity.GeneratedAt) || prompt.Timezone != identity.Timezone || prompt.ValidPeriod != identity.ValidPeriod || !reflect.DeepEqual(prompt.SourceWarnings, identity.SourceWarnings) {
		t.Fatalf("prompt metadata does not match prepared identity: %#v/%#v", prompt, identity)
	}

	moduleMetadata, found, err := module.StanzaValue[briefing.MetadataModule](prepared.moduleSnapshot, "metadata")
	if err != nil || !found {
		t.Fatalf("metadata stanza = %#v/%t/%v", moduleMetadata, found, err)
	}
	if moduleMetadata.RunID != identity.RunID || moduleMetadata.ReportID != identity.ReportID || moduleMetadata.Variant != identity.Variant || moduleMetadata.PromptID != identity.PromptID || !moduleMetadata.GeneratedAt.Equal(identity.GeneratedAt) || moduleMetadata.Units != identity.Units || moduleMetadata.Timezone != identity.Timezone || moduleMetadata.ValidPeriod != identity.ValidPeriod || !reflect.DeepEqual(moduleMetadata.Location, identity.Location) {
		t.Fatalf("module metadata does not match prepared identity: %#v/%#v", moduleMetadata, identity)
	}
	if len(moduleMetadata.SourceWarnings) != len(identity.SourceWarnings) {
		t.Fatalf("module source warnings = %#v, want %#v", moduleMetadata.SourceWarnings, identity.SourceWarnings)
	}
	for index, warning := range identity.SourceWarnings {
		summary := moduleMetadata.SourceWarnings[index]
		if summary.Source != warning.Source || summary.Code != warning.Code || summary.Severity != warning.Severity || summary.Message != warning.Message || summary.CompletenessImpact != warning.CompletenessImpact {
			t.Fatalf("module source warning %d = %#v, want %#v", index, summary, warning)
		}
	}
}

func preparedHandler(t *testing.T, resolved report.Resolved) generatedtext.Handler {
	t.Helper()
	handler, err := generatedtext.LookupDefinition(resolved.Definition)
	if err != nil {
		t.Fatalf("LookupDefinition() error = %v", err)
	}
	return handler
}