package main

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

// The shape ADR 0480 clauses 1, 2, 3 and 5 give the bus's manifest: the upstream image by digest, the mesh's two
// programs mounted read-only under /opt, unpacked by archive resources the container names under restart-on
// (the node-engine does not look inside a mounted directory), and the container the same one it was.
func TestTheBussManifestMountsItsProgramsIntoTheUpstreamImage(t *testing.T) {
	raw, err := os.ReadFile("../../module.json")
	if err != nil {
		t.Fatal(err)
	}
	var m struct {
		Data struct {
			Own []struct {
				ID     string `json:"id"`
				Backup struct {
					Dump string `json:"dump"`
				} `json:"backup"`
			} `json:"own"`
		} `json:"data"`
		Resources []map[string]any `json:"resources"`
		Build     struct {
			On        any `json:"on"`
			Artifacts []struct {
				Name, Kind, From, Language, System, Binary string
			} `json:"artifacts"`
		} `json:"build"`
	}
	if err := json.Unmarshal(raw, &m); err != nil {
		t.Fatal(err)
	}
	if m.Build.On != nil {
		t.Error("build.on is declared: nothing is built on a base image any more")
	}
	artifacts := map[string]struct{ Name, Kind, From, Language, System, Binary string }{}
	for _, a := range m.Build.Artifacts {
		artifacts[a.Name] = a
		if a.Kind == "image" {
			t.Errorf("artifact %s is an image built from a Dockerfile (ADR 0452)", a.Name)
		}
	}
	if a := artifacts["server"]; a.Kind != "upstream" || !strings.Contains(a.From, "@sha256:") {
		t.Errorf("server is %+v: an upstream image pinned by digest", a)
	}
	if a := artifacts["snapshot"]; a.Kind != "bundle" || a.Language != "go" || a.System != "alpine" ||
		a.From != "cmd/mesh-nats-snapshot" || a.Binary != "mesh-nats-snapshot" {
		t.Errorf("snapshot is %+v: a Go bundle of the module's own package, stamped for alpine", a)
	}
	if a := artifacts["entrypoint"]; a.Kind != "archive" || a.From != "program" {
		t.Errorf("entrypoint is %+v: an archive of program/", a)
	}
	if _, err := os.Stat("../../program/entrypoint.sh"); err != nil {
		t.Error(err)
	}
	if _, err := os.Stat("../../Dockerfile"); err == nil {
		t.Error("the Dockerfile is still there")
	}

	byID := map[string]map[string]any{}
	for _, r := range m.Resources {
		byID[r["id"].(string)] = r
	}
	server := byID["server"]
	if server["name"] != "mesh-broker-nats" || server["artifact"] != "server" {
		t.Errorf("the container is %v on artifact %v: it keeps its name, which the dump and the jails use", server["name"], server["artifact"])
	}
	volumes, _ := server["volumes"].([]any)
	restart, _ := server["restart-on"].([]any)
	for _, p := range []struct{ resource, artifact, mount string }{
		{"program-snapshot", "snapshot", ":/opt/mesh:ro"},
		{"program-entrypoint", "entrypoint", ":/opt/mesh-entrypoint:ro"},
	} {
		r := byID[p.resource]
		if r == nil || r["type"] != "archive" || r["artifact"] != p.artifact {
			t.Errorf("%s is %v: an archive resource unpacking %s", p.resource, r, p.artifact)
			continue
		}
		// Under a directory the module declares (ADR 0030: nothing is mounted from a path no resource covers).
		if dir, _, _ := strings.Cut(strings.TrimPrefix(r["path"].(string), "${dir:"), "}"); !strings.HasPrefix(r["path"].(string), "${dir:") ||
			byID[dir] == nil || byID[dir]["type"] != "directory" {
			t.Errorf("%s is at %v: not under a directory the module declares", p.resource, r["path"])
		}
		mounted := false
		for _, v := range volumes {
			if v == r["path"].(string)+p.mount {
				mounted = true
			}
		}
		if !mounted {
			t.Errorf("%s is not mounted read-only as %s", p.resource, p.mount)
		}
		named := false
		for _, v := range restart {
			named = named || v == p.resource
		}
		if !named {
			t.Errorf("%s is not in the container's restart-on: a new program would leave the old one running", p.resource)
		}
	}
	args, _ := server["args"].([]any)
	if len(args) != 2 || args[0] != "sh" || args[1] != "/opt/mesh-entrypoint/entrypoint.sh" {
		t.Errorf("args are %v: the entrypoint run through sh, so no execute bit is relied on", args)
	}
	for _, d := range m.Data.Own {
		if d.ID == "jetstream" && !strings.Contains(d.Backup.Dump, "docker exec -i mesh-broker-nats /opt/mesh/mesh-nats-snapshot snapshot") {
			t.Errorf("the dump is %q: it calls the mounted program", d.Backup.Dump)
		}
	}
}