package module

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

type testStanza struct {
	Message string `json:"message"`
	Count   int    `json:"count"`
}

func TestSnapshotPreservesOutputOrderAndJSON(t *testing.T) {
	snapshot, err := NewSnapshot([]Output{
		{ID: Metadata, StanzaName: "metadata", Value: testStanza{Message: "first", Count: 1}},
		{ID: AlertDigest, StanzaName: "alert_digest", Value: testStanza{Message: "second", Count: 2}},
	})
	if err != nil {
		t.Fatalf("NewSnapshot() error = %v", err)
	}
	if snapshot.SchemaVersion != SnapshotSchemaVersion {
		t.Fatalf("SchemaVersion = %q, want %q", snapshot.SchemaVersion, SnapshotSchemaVersion)
	}
	if snapshot.Outputs[0].ID != Metadata || snapshot.Outputs[1].ID != AlertDigest {
		t.Fatalf("Outputs order = %#v, want input order", snapshot.Outputs)
	}

	data, err := json.Marshal(snapshot)
	if err != nil {
		t.Fatalf("Marshal() error = %v", err)
	}
	got := string(data)
	want := `{"schemaVersion":"weatherreporter.modules.v1","outputs":[{"id":"metadata","stanzaName":"metadata","value":{"message":"first","count":1}},{"id":"alert_digest","stanzaName":"alert_digest","value":{"message":"second","count":2}}]}`
	if got != want {
		t.Fatalf("json = %s, want %s", got, want)
	}
}

func TestSnapshotRejectsDuplicateOutputs(t *testing.T) {
	_, err := NewSnapshot([]Output{
		{ID: Metadata, StanzaName: "metadata", Value: struct{}{}},
		{ID: Metadata, StanzaName: "other_metadata", Value: struct{}{}},
	})
	if err == nil || !strings.Contains(err.Error(), `duplicate module output "metadata"`) {
		t.Fatalf("duplicate module error = %v, want duplicate module output", err)
	}

	_, err = NewSnapshot([]Output{
		{ID: Metadata, StanzaName: "metadata", Value: struct{}{}},
		{ID: CurrentConditions, StanzaName: "metadata", Value: struct{}{}},
	})
	if err == nil || !strings.Contains(err.Error(), `duplicate stanza name "metadata"`) {
		t.Fatalf("duplicate stanza error = %v, want duplicate stanza name", err)
	}
}

func TestStanzaValueDecodesTypedOutput(t *testing.T) {
	snapshot, err := NewSnapshot([]Output{
		{ID: Metadata, StanzaName: "metadata", Value: testStanza{Message: "available", Count: 3}},
	})
	if err != nil {
		t.Fatalf("NewSnapshot() error = %v", err)
	}

	value, found, err := StanzaValue[testStanza](snapshot, "metadata")
	if err != nil {
		t.Fatalf("StanzaValue() error = %v", err)
	}
	if !found {
		t.Fatal("StanzaValue() found = false, want true")
	}
	if value.Message != "available" || value.Count != 3 {
		t.Fatalf("StanzaValue() = %#v, want decoded stanza", value)
	}

	_, found, err = StanzaValue[testStanza](snapshot, "missing")
	if err != nil {
		t.Fatalf("StanzaValue(missing) error = %v", err)
	}
	if found {
		t.Fatal("StanzaValue(missing) found = true, want false")
	}
}

func TestSPCConvectiveModuleContractsAreStable(t *testing.T) {
	if SPCConvectiveOutlooks != ID("spc_convective_outlooks") {
		t.Fatalf("SPCConvectiveOutlooks = %q, want stable source/module ID", SPCConvectiveOutlooks)
	}
	if SPCConvectiveDiscussion != ID("spc_convective_discussion") {
		t.Fatalf("SPCConvectiveDiscussion = %q, want stable discussion module ID", SPCConvectiveDiscussion)
	}
	if CollectedSPCConvectiveOutlooks != FactRequirement("collected.spc_convective_outlooks") {
		t.Fatalf("CollectedSPCConvectiveOutlooks = %q, want collected requirement", CollectedSPCConvectiveOutlooks)
	}
	if RequiresDerivedSPCConvectiveOutlooks != FactRequirement("derived.spc_convective_outlooks") {
		t.Fatalf("RequiresDerivedSPCConvectiveOutlooks = %q, want derived requirement", RequiresDerivedSPCConvectiveOutlooks)
	}

	_ = SPCConvectiveOutlooksOptions{}
	_ = SPCConvectiveDiscussionOptions{}
}

func TestDailyPlanningModuleContractIsStable(t *testing.T) {
	if DailyPlanning != ID("daily_planning") {
		t.Fatalf("DailyPlanning = %q, want stable module ID", DailyPlanning)
	}

	_ = DailyPlanningOptions{}
}