package httpapi

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

	"basicstack.de/proofedmesh/services/admin-api/internal/store"
)

func newDeps(t *testing.T) Dependencies {
	t.Helper()
	return Dependencies{
		Store: store.NewMemory(),
		Now:   func() time.Time { return time.Date(2026, 10, 25, 12, 0, 0, 0, time.UTC) },
	}
}

func newMux(deps Dependencies) http.Handler {
	mux := http.NewServeMux()
	Mount(mux, deps)
	// inject a principal for tests
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ctx := WithPrincipal(r.Context(), "test-admin")
		mux.ServeHTTP(w, r.WithContext(ctx))
	})
}

func TestList_Empty(t *testing.T) {
	srv := httptest.NewServer(newMux(newDeps(t)))
	defer srv.Close()
	resp, err := http.Get(srv.URL + "/admin/per-diem-rates/")
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		t.Fatalf("status %d", resp.StatusCode)
	}
}

func TestCreateAndGet_JSON(t *testing.T) {
	deps := newDeps(t)
	srv := httptest.NewServer(newMux(deps))
	defer srv.Close()
	body := `{
		"country":"DE","currency":"EUR",
		"full_day":"28.00","partial_day_min8h":"14.00",
		"arrival_day":"14.00","departure_day":"14.00",
		"valid_from":"2026-01-01T00:00:00Z",
		"source_regulation":"BMF 2026"
	}`
	req, _ := http.NewRequest("POST", srv.URL+"/admin/per-diem-rates/", strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusCreated {
		t.Fatalf("expected 201, got %d", resp.StatusCode)
	}
	var out map[string]map[string]any
	_ = json.NewDecoder(resp.Body).Decode(&out)
	rateID, _ := out["rate"]["rate_id"].(string)
	if rateID == "" {
		t.Fatalf("no rate_id in response: %v", out)
	}

	// Fetch it back
	resp2, err := http.Get(srv.URL + "/admin/per-diem-rates/" + rateID)
	if err != nil {
		t.Fatal(err)
	}
	defer resp2.Body.Close()
	if resp2.StatusCode != 200 {
		t.Fatalf("get status %d", resp2.StatusCode)
	}
}

func TestCreate_InvalidBody_Rejected(t *testing.T) {
	srv := httptest.NewServer(newMux(newDeps(t)))
	defer srv.Close()
	body := `{"country":"XYZ","currency":"EUR","full_day":"28.00","partial_day_min8h":"14.00","arrival_day":"14.00","departure_day":"14.00","valid_from":"2026-01-01T00:00:00Z","source_regulation":"BMF 2026"}`
	req, _ := http.NewRequest("POST", srv.URL+"/admin/per-diem-rates/", strings.NewReader(body))
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 400 {
		t.Fatalf("expected 400, got %d", resp.StatusCode)
	}
}

func TestGet_NotFound(t *testing.T) {
	srv := httptest.NewServer(newMux(newDeps(t)))
	defer srv.Close()
	resp, err := http.Get(srv.URL + "/admin/per-diem-rates/PDR-999")
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusNotFound {
		t.Fatalf("expected 404, got %d", resp.StatusCode)
	}
}

func TestRetire_UpdatesValidTo(t *testing.T) {
	deps := newDeps(t)
	srv := httptest.NewServer(newMux(deps))
	defer srv.Close()

	createBody := `{"country":"DE","currency":"EUR","full_day":"28.00","partial_day_min8h":"14.00","arrival_day":"14.00","departure_day":"14.00","valid_from":"2026-01-01T00:00:00Z","source_regulation":"BMF 2026"}`
	req, _ := http.NewRequest("POST", srv.URL+"/admin/per-diem-rates/", strings.NewReader(createBody))
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	var out map[string]map[string]any
	_ = json.NewDecoder(resp.Body).Decode(&out)
	rateID := out["rate"]["rate_id"].(string)

	retireBody := `{"valid_to":"2026-06-30"}`
	req2, _ := http.NewRequest("POST", srv.URL+"/admin/per-diem-rates/"+rateID+"/retire", strings.NewReader(retireBody))
	req2.Header.Set("Content-Type", "application/json")
	resp2, err := http.DefaultClient.Do(req2)
	if err != nil {
		t.Fatal(err)
	}
	defer resp2.Body.Close()
	if resp2.StatusCode != 200 {
		t.Fatalf("retire: expected 200, got %d", resp2.StatusCode)
	}
	var out2 map[string]map[string]any
	_ = json.NewDecoder(resp2.Body).Decode(&out2)
	if _, ok := out2["rate"]["valid_to"]; !ok {
		t.Fatal("expected valid_to to be set after retire")
	}
}

func TestOverlap_Rejected(t *testing.T) {
	srv := httptest.NewServer(newMux(newDeps(t)))
	defer srv.Close()

	body := func(validFrom string, validTo *string) string {
		base := `{"country":"DE","currency":"EUR","full_day":"28.00","partial_day_min8h":"14.00","arrival_day":"14.00","departure_day":"14.00","valid_from":"` + validFrom + `T00:00:00Z","source_regulation":"BMF 2026"`
		if validTo != nil {
			base += `,"valid_to":"` + *validTo + `T00:00:00Z"`
		}
		return base + "}"
	}

	vt := "2026-12-31"
	req1, _ := http.NewRequest("POST", srv.URL+"/admin/per-diem-rates/", strings.NewReader(body("2026-01-01", &vt)))
	req1.Header.Set("Content-Type", "application/json")
	resp1, err := http.DefaultClient.Do(req1)
	if err != nil {
		t.Fatal(err)
	}
	defer resp1.Body.Close()
	if resp1.StatusCode != http.StatusCreated {
		t.Fatalf("first create expected 201, got %d", resp1.StatusCode)
	}

	req2, _ := http.NewRequest("POST", srv.URL+"/admin/per-diem-rates/", strings.NewReader(body("2026-12-31", nil)))
	req2.Header.Set("Content-Type", "application/json")
	resp2, err := http.DefaultClient.Do(req2)
	if err != nil {
		t.Fatal(err)
	}
	defer resp2.Body.Close()
	if resp2.StatusCode != http.StatusConflict {
		t.Fatalf("overlapping create: expected 409, got %d", resp2.StatusCode)
	}
}