package catalogue

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

// A route contribution has an agreed vocabulary (route.go), and the parser holds a manifest to it:
// a key no proxy reads is refused rather than carried, a route with no port is refused rather than
// skipped by the proxy it asked for, and a body limit is a whole number of bytes or nothing.
//
// The limit is here for the registry's hand-over (novox/hq ADR 0082, ADR 0104): a registry takes
// image layers in single requests of gigabytes, and the predecessor served its public name with a
// twenty-gigabyte middleware. A route that could not say so would have a name it could not be
// pushed to.

func routed(contribution string) ([]byte, error) {
	raw := []byte(`{"module":"app","version":"1","contributes":{"route":` + contribution + `}}`)
	_, err := ParseManifest(raw)
	return raw, err
}

func TestARouteWithALabelAndAPortIsAccepted(t *testing.T) {
	if _, err := routed(`{"label":"git","port":3000}`); err != nil {
		t.Fatalf("the shape every routed module in the catalogue writes was refused: %v", err)
	}
	// The legacy shape — a full name and no label — still passes, so the catalogue can migrate
	// module by module (ADR 0066).
	if _, err := routed(`{"name":"git.example","port":3000}`); err != nil {
		t.Fatalf("a legacy full-name contribution was refused: %v", err)
	}
	// And a limit on what may be pushed through it.
	if _, err := routed(`{"label":"registry-api","port":5001,"max-request-body":21474836480}`); err != nil {
		t.Fatalf("a route with a body limit was refused: %v", err)
	}
}

func TestARouteKeyNoProxyReadsIsRefusedByName(t *testing.T) {
	_, err := routed(`{"label":"git","port":3000,"basic-auth":true,"timeout":30}`)
	if err == nil {
		t.Fatal("a route carrying keys no proxy reads was accepted; the module goes on believing " +
			"its route is limited when it is not")
	}
	for _, want := range []string{`"basic-auth"`, `"timeout"`, "max-request-body"} {
		if !strings.Contains(err.Error(), want) {
			t.Errorf("the refusal does not name %s, leaving the author guessing: %v", want, err)
		}
	}
}

func TestARouteWithNoPortIsRefused(t *testing.T) {
	// A module that asked for a route and not for the port is unreachable by the proxy it just
	// asked for (08-connectivity §3) — found at parse time, not in a proxy's log.
	if _, err := routed(`{"label":"git"}`); err == nil || !strings.Contains(err.Error(), "port") {
		t.Fatalf("a route with nowhere to send it was accepted: %v", err)
	}
	for _, bad := range []string{`"3000"`, `0`, `70000`, `3000.5`, `true`} {
		if _, err := routed(`{"label":"git","port":` + bad + `}`); err == nil {
			t.Errorf("a route on port %s was accepted, and that is not a port", bad)
		}
	}
	// And a route that names nothing.
	if _, err := routed(`{"port":3000}`); err == nil || !strings.Contains(err.Error(), "label") {
		t.Fatalf("a route naming nothing was accepted: %v", err)
	}
	if _, err := routed(`{"label":"","port":3000}`); err == nil {
		t.Fatal("a route with an empty label was accepted")
	}
}

func TestABodyLimitIsAWholePositiveNumberOfBytes(t *testing.T) {
	for _, bad := range []string{`"20g"`, `"21474836480"`, `0`, `-1`, `1.5`, `true`, `null`} {
		_, err := routed(`{"label":"registry-api","port":5001,"max-request-body":` + bad + `}`)
		if err == nil || !strings.Contains(err.Error(), "max-request-body") {
			t.Errorf("a body limit of %s was accepted, or refused without naming the key: %v", bad, err)
		}
	}
	for _, v := range []any{float64(1), float64(21474836480), 1024, int64(4096)} {
		if _, ok := RouteBodyLimit(v); !ok {
			t.Errorf("%v (%T) is a whole positive number of bytes and was refused", v, v)
		}
	}
	for _, v := range []any{"1", float64(0), float64(0.5), nil, true} {
		if n, ok := RouteBodyLimit(v); ok {
			t.Errorf("%v (%T) was read as a limit of %d bytes", v, v, n)
		}
	}
}

// The limit reaches the proxy exactly as written, beside the composed name and the port — the
// mesh carries it and interprets nothing.
func TestABodyLimitReachesTheProxyUnchanged(t *testing.T) {
	registry := Manifest{Module: "gate", Version: "1",
		Contributes: map[string]map[string]any{
			"route": {"label": "registry-api", "port": 5001, "max-request-body": float64(21474836480)},
		}}
	proxy := Manifest{Module: "proxy", Version: "1",
		Provides: Offers("route"),
		Receives: map[string]string{"route": "/var/lib/proxy/routes.json"}}
	got, err := Resolve(shelf(proxy, registry), []string{"gate"}, withDomain("example.test"), World{})
	if err != nil {
		t.Fatal(err)
	}
	for _, r := range mustDeclare(t, got) {
		if r["path"] != "/var/lib/proxy/routes.json" {
			continue
		}
		var parsed struct {
			Given []Contribution `json:"given"`
		}
		if err := json.Unmarshal([]byte(r["content"].(string)), &parsed); err != nil {
			t.Fatal(err)
		}
		if len(parsed.Given) != 1 {
			t.Fatalf("the proxy was given %d routes", len(parsed.Given))
		}
		v := parsed.Given[0].Values
		if v["name"] != "registry-api.example.test" {
			t.Errorf("the name did not compose: %v", v)
		}
		if limit, ok := RouteBodyLimit(v["max-request-body"]); !ok || limit != 21474836480 {
			t.Errorf("the body limit did not reach the proxy as written: %v", v["max-request-body"])
		}
		return
	}
	t.Fatal("the proxy was given no file")
}