package manifest

import (
	"bytes"
	"encoding/json"
	"io/fs"
	"os"
	"path/filepath"
	"reflect"
	"slices"
	"strings"
	"testing"
)

// The controller's manifest reader is mesh-controller internal/catalogue (ParseManifest), an internal package of another
// repository, which this module cannot import. These tests therefore decode the manifest strictly into the fields its
// Manifest type names (DisallowUnknownFields, as its parseManifest does) and check the rules the issue names.
// **The merge gate's module check is what proves the controller takes this manifest (1135/AC6); these tests hold the
// rules so a unit run catches a refusal early.**

type state struct {
	Name    string `json:"name"`
	History int    `json:"history,omitempty"`
	KeyTTL  bool   `json:"key-ttl,omitempty"`
}

type artifact struct {
	Name     string `json:"name"`
	Kind     string `json:"kind"`
	Language string `json:"language"`
	System   string `json:"system"`
	From     string `json:"from"`
	Binary   string `json:"binary"`
	Context  *struct {
		Repository string `json:"repository"`
	} `json:"context"`
}

type manifest struct {
	Module       string            `json:"module"`
	Moved        bool              `json:"moved"`
	Version      string            `json:"version"`
	Slug         string            `json:"slug"`
	Reads        []string          `json:"reads"`
	State        []state           `json:"state"`
	OwnSecrets   map[string]string `json:"own-secrets"`
	SecretsOwner string            `json:"secrets-owner"`
	Resources    []map[string]any  `json:"resources"`
	Build        struct {
		Artifacts []artifact `json:"artifacts"`
	} `json:"build"`
}

func load(t *testing.T) (manifest, map[string]json.RawMessage) {
	t.Helper()
	raw, err := os.ReadFile("module.json")
	if err != nil {
		t.Fatal(err)
	}
	var m manifest
	dec := json.NewDecoder(bytes.NewReader(raw))
	dec.DisallowUnknownFields()
	if err := dec.Decode(&m); err != nil {
		t.Fatalf("the controller's reader refuses a key this manifest has: %v", err)
	}
	var top map[string]json.RawMessage
	if err := json.Unmarshal(raw, &top); err != nil {
		t.Fatal(err)
	}
	return m, top
}

func TestManifestStateAndReads(t *testing.T) { // 1135/AC6
	m, top := load(t)
	if m.Module != "mesh-delivery-watchman" || m.Moved || m.Slug != "watchman" {
		t.Errorf("module %q moved %v (it has no template, so it is not moved) slug %q", m.Module, m.Moved, m.Slug)
	}
	want := []state{{Name: "presence", History: 20}, {Name: "pulse", KeyTTL: true}, {Name: "stuck", History: 20}}
	if !reflect.DeepEqual(m.State, want) {
		t.Errorf("state = %+v, want %+v", m.State, want)
	}
	reads := slices.Clone(m.Reads)
	slices.Sort(reads)
	if !reflect.DeepEqual(reads, []string{"mesh-controller.checks-running"}) {
		t.Errorf("reads = %v", reads)
	}
	for _, k := range []string{"emits", "context", "items", "consumes", "provides", "claims"} {
		if _, ok := top[k]; ok {
			t.Errorf("the manifest declares %q: the watchman has none", k)
		}
	}
	if b, ok := m.OwnSecrets["broker"]; !ok || len(m.OwnSecrets) != 1 || b != "${dir:state}/broker" {
		t.Errorf("own-secrets = %v, want exactly broker", m.OwnSecrets)
	}
	if m.SecretsOwner != "mesh-delivery-watchman" {
		t.Errorf("secrets-owner = %q", m.SecretsOwner)
	}
}

func TestManifestIsWholeInItsRepository(t *testing.T) { // 1135/AC6
	m, _ := load(t)
	if len(m.Build.Artifacts) != 1 {
		t.Fatalf("artifacts = %+v, want the one bundle program", m.Build.Artifacts)
	}
	a := m.Build.Artifacts[0]
	if a.Name != "program" || a.Kind != "bundle" || a.Language != "go" || a.System != "arch" || a.Context != nil {
		t.Errorf("artifact = %+v", a)
	}
	if st, err := os.Stat(a.From); err != nil || !st.IsDir() {
		t.Errorf("the artifact builds from %q, which is not a directory of this module", a.From)
	}
	if a.Binary != "mesh-delivery-watchman" || !strings.HasSuffix(a.From, a.Binary) {
		t.Errorf("binary %q from %q", a.Binary, a.From)
	}
}

func TestManifestResources(t *testing.T) { // 1135/AC6
	m, _ := load(t)
	byType := map[string][]map[string]any{}
	for _, r := range m.Resources {
		ty, _ := r["type"].(string)
		byType[ty] = append(byType[ty], r)
	}
	for _, ty := range []string{"user", "directory", "process"} {
		if len(byType[ty]) == 0 {
			t.Fatalf("no %s resource", ty)
		}
	}
	user := byType["user"][0]["name"]
	if user != "mesh-delivery-watchman" {
		t.Errorf("user = %v", user)
	}
	p := byType["process"][0]
	if p["user"] != user || p["artifact"] != "program" {
		t.Errorf("process = %v", p)
	}
	env, _ := p["env"].(map[string]any)
	if env["MESH_BROKER_FILE"] != "${dir:state}/broker" {
		t.Errorf("the process reads %v", env["MESH_BROKER_FILE"])
	}
	if h, _ := p["health"].(map[string]any); h["kind"] != "unit" {
		t.Errorf("health = %v", p["health"])
	}
	d := byType["directory"][0]
	if d["id"] != "state" || d["mode"] != "0700" || d["owner"] != user {
		t.Errorf("state directory = %v", d)
	}
}

func TestNoTickerTimerOrSleep(t *testing.T) { // 1135/AC7
	forbidden := []string{"time.Tick", "time.NewTicker", "time.Sleep", "time.After", "time.NewTimer", "time.AfterFunc"}
	var files int
	for _, root := range []string{"cmd", "internal"} {
		err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
			if err != nil || d.IsDir() || !strings.HasSuffix(path, ".go") || strings.HasSuffix(path, "_test.go") {
				return err
			}
			files++
			src, err := os.ReadFile(path)
			if err != nil {
				return err
			}
			for _, f := range forbidden {
				if strings.Contains(string(src), f) {
					t.Errorf("%s holds %s: the program holds no timer", path, f)
				}
			}
			return nil
		})
		if err != nil {
			t.Fatal(err)
		}
	}
	if files < 3 {
		t.Fatalf("read %d source files, want the program's", files)
	}
}