package forecastapi

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"github.com/itworx/pulse/internal/auth"
	"github.com/itworx/pulse/internal/forecast"
)

type providerFunc func(context.Context) (forecast.Snapshot, error)

func (f providerFunc) Snapshot(ctx context.Context) (forecast.Snapshot, error) { return f(ctx) }

func authenticatedRequest(method, path string) *http.Request {
	r := httptest.NewRequest(method, path, nil)
	return r.WithContext(auth.WithPrincipal(r.Context(), auth.Principal{Subject: "test", Role: auth.RoleViewer}))
}

func TestHandlerRequiresAuthenticationAndGET(t *testing.T) {
	h := Handler{}
	unauthenticated := httptest.NewRecorder()
	h.ServeHTTP(unauthenticated, httptest.NewRequest(http.MethodGet, "/api/v1/forecasts", nil))
	if unauthenticated.Code != http.StatusUnauthorized {
		t.Fatalf("status=%d", unauthenticated.Code)
	}
	method := httptest.NewRecorder()
	h.ServeHTTP(method, authenticatedRequest(http.MethodPost, "/api/v1/forecasts"))
	if method.Code != http.StatusNotFound {
		t.Fatalf("status=%d", method.Code)
	}
}

func TestHandlerReturnsBoundedSnapshotAndMapsProviderErrors(t *testing.T) {
	now := time.Date(2026, 8, 1, 12, 0, 0, 0, time.UTC)
	snapshot := forecast.Snapshot{ContractVersion: forecast.ContractVersion, GeneratedAt: now, QualifiedCount: 0, Items: []forecast.Forecast{{EntityID: "share", Method: forecast.MethodInsufficient, Confidence: forecast.ConfidenceNone, Reason: "insufficient_points"}}}
	h := Handler{Provider: providerFunc(func(context.Context) (forecast.Snapshot, error) { return snapshot, nil })}
	recorder := httptest.NewRecorder()
	h.ServeHTTP(recorder, authenticatedRequest(http.MethodGet, "/api/v1/forecasts"))
	if recorder.Code != http.StatusOK || recorder.Header().Get("Cache-Control") != "private, max-age=15" {
		t.Fatalf("status=%d headers=%v", recorder.Code, recorder.Header())
	}
	var got forecast.Snapshot
	if err := json.NewDecoder(recorder.Body).Decode(&got); err != nil {
		t.Fatal(err)
	}
	if got.QualifiedCount != 0 || len(got.Items) != 1 || got.Items[0].Reason != "insufficient_points" {
		t.Fatalf("snapshot=%+v", got)
	}

	failing := Handler{Provider: providerFunc(func(context.Context) (forecast.Snapshot, error) { return forecast.Snapshot{}, context.DeadlineExceeded })}
	deadline := httptest.NewRecorder()
	failing.ServeHTTP(deadline, authenticatedRequest(http.MethodGet, "/api/v1/forecasts"))
	if deadline.Code != http.StatusOK {
		t.Fatalf("deadline status=%d", deadline.Code)
	}
}