package meshtest

import (
	"encoding/json"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"testing"
)

// **The bus the tests run is the bus the mesh runs** (novox/hq ADR 0227 rule 9, ADR 0237): the server linked
// into the tests is held to the release the catalogue's bus image is — read from beside this checkout, as
// the build seat clones it for a merge check — and, given the facts snapshot, to the release the mesh's bus
// server says it runs. A bus upgrade moves the catalogue's pin; this then fails until go.mod's moves with it.
func TestTheBusTheTestsRunIsTheBusTheMeshRuns(t *testing.T) {
	beside := os.Getenv("MESH_CHECK_BESIDE")
	if beside == "" {
		beside = filepath.Join("..", "..", "..", "..")
	}
	dockerfile := filepath.Join(beside, "mesh-catalog", "modules", "nats", "Dockerfile")
	raw, err := os.ReadFile(dockerfile)
	switch {
	case err == nil:
		pinned := regexp.MustCompile(`upstream: nats ([0-9.]+)-alpine`).FindSubmatch(raw)
		if pinned == nil {
			t.Fatalf("%s says no release its digest is", dockerfile)
		}
		if string(pinned[1]) != Version {
			t.Errorf("the tests run bus %s and the catalogue's bus image is %s: move go.mod's nats-server pin with the image",
				Version, pinned[1])
		}
	case os.IsNotExist(err):
		t.Logf("the catalogue is not beside this checkout, so its bus image is not compared")
	default:
		t.Fatal(err)
	}
	path := os.Getenv("MESH_FACTS")
	if path == "" {
		t.Logf("no MESH_FACTS: the bus the mesh runs is compared in a merge check, which has it")
		return
	}
	body, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	var f struct {
		Taken    string `json:"taken"`
		Versions struct {
			Bus string `json:"bus"`
		} `json:"versions"`
	}
	if err := json.Unmarshal(body, &f); err != nil {
		t.Fatal(err)
	}
	if f.Versions.Bus != "" && strings.TrimPrefix(f.Versions.Bus, "v") != Version {
		t.Errorf("the tests run bus %s and the mesh's bus runs %s (facts of %s)", Version, f.Versions.Bus, f.Taken)
	}
}

// Each test is given a bus of its own, and the same one at every ask.
func TestEachTestHasABusOfItsOwn(t *testing.T) {
	var first string
	t.Run("one", func(t *testing.T) {
		first = URL(t)
		if URL(t) != first {
			t.Fatal("two buses for one test")
		}
	})
	t.Run("two", func(t *testing.T) {
		if URL(t) == first {
			t.Fatal("two tests were given one bus")
		}
	})
}