package taskapi

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"gitea.perlbach24.de/scripte/nexarch/common/testdb"
	"gitea.perlbach24.de/scripte/nexarch/workflow/internal/migrate"
	"gitea.perlbach24.de/scripte/nexarch/workflow/internal/task"
)

func findModuleRoot(t *testing.T) string {
	t.Helper()
	dir, err := os.Getwd()
	if err != nil {
		t.Fatalf("getwd: %v", err)
	}
	for {
		if _, err := os.Stat(filepath.Join(dir, "go.mod")); err == nil {
			return dir
		}
		parent := filepath.Dir(dir)
		if parent == dir {
			t.Fatal("go.mod nicht gefunden")
		}
		dir = parent
	}
}

func newTestServer(t *testing.T) (*Server, *task.Store) {
	t.Helper()
	dsn := os.Getenv("TEST_TENANT_DSN")
	if dsn == "" {
		t.Skip("TEST_TENANT_DSN nicht gesetzt, Integrationstest uebersprungen")
	}
	ctx := context.Background()
	pool := testdb.Pool(t, dsn)
	migrations, err := migrate.Load(filepath.Join(findModuleRoot(t), "migrations", "tenant"))
	if err != nil {
		t.Fatalf("migrationen laden: %v", err)
	}
	if _, err := migrate.Up(ctx, pool, migrations); err != nil {
		t.Fatalf("migrationen anwenden: %v", err)
	}
	store := task.NewStore(pool)
	return NewServer(store, "acme"), store
}

func TestHandleList_RequiresAuth(t *testing.T) {
	srv, _ := newTestServer(t)
	mux := http.NewServeMux()
	srv.RegisterRoutes(mux)

	req := httptest.NewRequest(http.MethodGet, "/tasks", nil)
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)
	if w.Code != http.StatusUnauthorized {
		t.Fatalf("erwartet 401 ohne X-User-Id/X-Tenant-Slug, bekam %d", w.Code)
	}
}

func TestHandleList_RejectsForeignTenant(t *testing.T) {
	srv, _ := newTestServer(t)
	mux := http.NewServeMux()
	srv.RegisterRoutes(mux)

	req := httptest.NewRequest(http.MethodGet, "/tasks", nil)
	req.Header.Set("X-User-Id", "u1")
	req.Header.Set("X-Tenant-Slug", "fremd")
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)
	if w.Code != http.StatusForbidden {
		t.Fatalf("erwartet 403 bei fremdem tenant, bekam %d", w.Code)
	}
}

func TestHandleList_ReturnsTasksForOwnTenant(t *testing.T) {
	srv, store := newTestServer(t)
	ctx := context.Background()
	id, err := store.Create(ctx, task.Task{Title: "API-Liste-Test", AssigneeType: task.AssigneePerson, AssigneeID: "u1"})
	if err != nil {
		t.Fatalf("create: %v", err)
	}

	mux := http.NewServeMux()
	srv.RegisterRoutes(mux)

	req := httptest.NewRequest(http.MethodGet, "/tasks", nil)
	req.Header.Set("X-User-Id", "u1")
	req.Header.Set("X-Tenant-Slug", "acme")
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)
	if w.Code != http.StatusOK {
		t.Fatalf("erwartet 200, bekam %d: %s", w.Code, w.Body.String())
	}
	var tasks []task.Task
	if err := json.NewDecoder(w.Body).Decode(&tasks); err != nil {
		t.Fatalf("decode: %v", err)
	}
	found := false
	for _, tk := range tasks {
		if tk.ID == id {
			found = true
		}
	}
	if !found {
		t.Fatal("erstellte aufgabe fehlt in der antwort")
	}
}

func TestHandleSetStatus_DragAndDropUpdatesViaTSK01(t *testing.T) {
	srv, store := newTestServer(t)
	ctx := context.Background()
	id, err := store.Create(ctx, task.Task{Title: "Drag-Test", AssigneeType: task.AssigneePerson, AssigneeID: "u1"})
	if err != nil {
		t.Fatalf("create: %v", err)
	}

	mux := http.NewServeMux()
	srv.RegisterRoutes(mux)

	body := strings.NewReader(`{"status":"in_progress"}`)
	req := httptest.NewRequest(http.MethodPatch, "/tasks/"+id+"/status", body)
	req.Header.Set("X-User-Id", "u1")
	req.Header.Set("X-Tenant-Slug", "acme")
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)
	if w.Code != http.StatusNoContent {
		t.Fatalf("erwartet 204, bekam %d: %s", w.Code, w.Body.String())
	}

	// Nachweis: der Status wurde tatsaechlich ueber TSK-01 (task.Store)
	// zurueckgeschrieben, nicht nur im Handler simuliert.
	got, err := store.Get(ctx, id)
	if err != nil {
		t.Fatalf("get: %v", err)
	}
	if got.Status != task.StatusInProgress {
		t.Fatalf("erwartet in_progress nach drag&drop, war %q", got.Status)
	}
}

func TestHandleSetStatus_UnknownTask(t *testing.T) {
	srv, _ := newTestServer(t)
	mux := http.NewServeMux()
	srv.RegisterRoutes(mux)

	body := strings.NewReader(`{"status":"done"}`)
	req := httptest.NewRequest(http.MethodPatch, "/tasks/00000000-0000-0000-0000-000000000000/status", body)
	req.Header.Set("X-User-Id", "u1")
	req.Header.Set("X-Tenant-Slug", "acme")
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)
	if w.Code != http.StatusNotFound {
		t.Fatalf("erwartet 404, bekam %d", w.Code)
	}
}

func TestHandleSetStatus_InvalidStatus(t *testing.T) {
	srv, store := newTestServer(t)
	ctx := context.Background()
	id, err := store.Create(ctx, task.Task{Title: "Ungueltig-API-Test", AssigneeType: task.AssigneePerson, AssigneeID: "u1"})
	if err != nil {
		t.Fatalf("create: %v", err)
	}

	mux := http.NewServeMux()
	srv.RegisterRoutes(mux)

	body := strings.NewReader(`{"status":"erfunden"}`)
	req := httptest.NewRequest(http.MethodPatch, "/tasks/"+id+"/status", body)
	req.Header.Set("X-User-Id", "u1")
	req.Header.Set("X-Tenant-Slug", "acme")
	w := httptest.NewRecorder()
	mux.ServeHTTP(w, req)
	if w.Code != http.StatusBadRequest {
		t.Fatalf("erwartet 400, bekam %d", w.Code)
	}
}