package catalogue

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

// A module declares its config (novox/hq ADR 0348 §1, §4, §5, §6, §8, §11; design 57 package K1, issue 660):
// one registration refusal per rule of design 57's K1, the old names read as aliases, and a module rewritten
// from settings to config composing byte-identically.

// inConfigForm is a module in the config form that registers: every value typed, described, defaulted or
// required, placed in a file or read at runtime, and its mergeable file naming its keys.
func inConfigForm() map[string]any {
	return map[string]any{
		"module":  "notifier",
		"version": "1",
		"config": map[string]any{
			"font-size": map[string]any{"type": "number", "description": "the notification's font size, in points",
				"minimum": 6, "maximum": 40, "default": 10},
			"width": map[string]any{"type": "number", "description": "the notification's width, in pixels",
				"default": 250},
			"position": map[string]any{"type": "string", "description": "the corner it shows in, a word",
				"enum": []any{"top-right", "top-left"}, "default": "top-right"},
			"theme": map[string]any{"type": "string", "description": "the colour theme, a lower-case name",
				"pattern": "[a-z]+", "default": "dark"},
			"history": map[string]any{"type": "number", "description": "how many notifications it keeps, a count",
				"default": 20, "runtime": true},
			"sender": map[string]any{"type": "string", "description": "the address it mails a digest from",
				"required": true},
		},
		"resources": []any{
			map[string]any{"id": "configuration", "type": "file", "path": "/x/notifierrc",
				"content": "font = Inter ${config:font-size}\nwidth = ${config:width}\nfrom = ${config:sender}\n"},
			map[string]any{"id": "rules", "type": "file", "path": "/x/rules.json", "merge": "json",
				"takes-config": []any{"position", "theme"}, "content": "{\"position\": \"top-right\"}\n"},
			map[string]any{"id": "notifier", "type": "service", "unit": "notifier.service",
				"reload-on": []any{"configuration"}, "restart-on": []any{"rules"}},
		},
	}
}

// declaration is one value of inConfigForm's config, to change in place.
func declaration(m map[string]any, key string) map[string]any {
	return m["config"].(map[string]any)[key].(map[string]any)
}

func resourceOf(m map[string]any, id string) map[string]any {
	for _, r := range m["resources"].([]any) {
		if r.(map[string]any)["id"] == id {
			return r.(map[string]any)
		}
	}
	return nil
}

func parseRaw(t *testing.T, m map[string]any) (Manifest, error) {
	t.Helper()
	raw, err := json.Marshal(m)
	if err != nil {
		t.Fatal(err)
	}
	return ParseManifest(raw)
}

// refused is that the manifest is refused with every one of these words.
func refused(t *testing.T, m map[string]any, words ...string) {
	t.Helper()
	_, err := parseRaw(t, m)
	if err == nil {
		t.Fatalf("registered; wanted a refusal saying %q", words)
	}
	for _, w := range words {
		if !strings.Contains(err.Error(), w) {
			t.Fatalf("refused without %q:\n%v", w, err)
		}
	}
}

func TestAModuleInTheConfigFormRegisters(t *testing.T) {
	m, err := parseRaw(t, inConfigForm())
	if err != nil {
		t.Fatal(err)
	}
	if !m.DeclaresConfig() {
		t.Fatal("a module declaring config is not read as in the config form")
	}
	d := m.Settings["font-size"]
	if d.Type != "number" || d.Description == "" || d.Minimum == nil || *d.Minimum != 6 || d.Default != float64(10) {
		t.Fatalf("font-size read as %+v", d)
	}
	if s := m.Settings["sender"]; !s.Required || s.Default != nil {
		t.Fatalf("sender read as %+v", s)
	}
}

// Rule 1: a value without type or description.
func TestConfigRefusesAValueWithoutTypeOrDescription(t *testing.T) {
	m := inConfigForm()
	delete(declaration(m, "width"), "type")
	refused(t, m, `notifier's config value "width"`, "no type")
	m = inConfigForm()
	declaration(m, "width")["type"] = "colour"
	refused(t, m, `"width"`, `type "colour"`)
	m = inConfigForm()
	delete(declaration(m, "width"), "description")
	refused(t, m, `"width"`, "no description")
}

// Rule 2: a value with neither a default nor required.
func TestConfigRefusesAValueWithNeitherDefaultNorRequired(t *testing.T) {
	m := inConfigForm()
	delete(declaration(m, "width"), "default")
	refused(t, m, `"width"`, "neither a default nor required")
	m = inConfigForm()
	declaration(m, "sender")["default"] = "noreply@example.org"
	refused(t, m, `"sender"`, "both a default and required")
}

// Rule 3: a default failing its validation.
func TestConfigRefusesADefaultFailingItsValidation(t *testing.T) {
	for _, c := range []struct {
		key   string
		value any
		said  string
	}{
		{"font-size", 4, "below its minimum"},
		{"font-size", 41, "above its maximum"},
		{"font-size", "10", "not a number"},
		{"position", "bottom", "not one of"},
		{"theme", "Dark", "does not match"},
	} {
		m := inConfigForm()
		declaration(m, c.key)["default"] = c.value
		refused(t, m, `"`+c.key+`"`, c.said)
	}
}

// Rule 4: an object or a list not trusted.
func TestConfigRefusesAnObjectOrListNotTrusted(t *testing.T) {
	for _, kind := range []string{"object", "list"} {
		m := inConfigForm()
		def := any(map[string]any{"a": 1})
		if kind == "list" {
			def = []any{"a"}
		}
		m["config"].(map[string]any)["rules"] = map[string]any{"type": kind, "description": "the rules, as " + kind,
			"default": def, "runtime": true}
		refused(t, m, `"rules"`, "is "+kind+" and not trusted")
		m["config"].(map[string]any)["rules"].(map[string]any)["trusted"] = true
		if _, err := parseRaw(t, m); err != nil {
			t.Fatalf("a trusted %s is refused: %v", kind, err)
		}
	}
}

// withPredefined is the list of predefined keys the mesh published, for the length of a test.
func withPredefined(t *testing.T, keys PredefinedList) {
	t.Helper()
	was := ReplacePublished(keys)
	t.Cleanup(func() { ReplacePublished(was) })
}

// Rule 5: a predefined key not on the list, or of another type. Where no list is present, a value naming one is
// refused saying so.
func TestConfigRefusesAPredefinedKeyNotOnTheListOrOfAnotherType(t *testing.T) {
	withPredefined(t, nil)
	m := inConfigForm()
	declaration(m, "font-size")["predefined"] = "font-size"
	refused(t, m, `"font-size"`, "the list of predefined keys", "is not present")

	withPredefined(t, map[string]PredefinedKey{"font-size": {Type: "number"}, "accent": {Type: "string"}})
	if _, err := parseRaw(t, m); err != nil {
		t.Fatalf("a value falling back to a listed key of its type is refused: %v", err)
	}
	m = inConfigForm()
	declaration(m, "font-size")["predefined"] = "font-scale"
	refused(t, m, `"font-size"`, `"font-scale"`, "not on the list")
	m = inConfigForm()
	declaration(m, "font-size")["predefined"] = "accent"
	refused(t, m, `"font-size"`, `"accent"`, "is a string")
}

// Rule 6: an untrusted value falling back to a trusted predefined key.
func TestConfigRefusesAnUntrustedValueFallingBackToATrustedKey(t *testing.T) {
	withPredefined(t, nil)
	m := inConfigForm()
	declaration(m, "theme")["predefined"] = "theme"
	refused(t, m, `"theme"`, "is not present")

	withPredefined(t, map[string]PredefinedKey{"theme": {Type: "string", Trusted: true}})
	refused(t, m, `"theme"`, "trusted", "is not")
	declaration(m, "theme")["trusted"] = true
	if _, err := parseRaw(t, m); err != nil {
		t.Fatalf("a trusted value falling back to a trusted key is refused: %v", err)
	}
}

// Rule 7: a value neither placed in a template nor read at runtime.
func TestConfigRefusesAValueNeitherPlacedNorReadAtRuntime(t *testing.T) {
	m := inConfigForm()
	delete(declaration(m, "history"), "runtime")
	refused(t, m, `"history"`, "${config:history}", `"runtime": true`)
	// Taken by a mergeable file is placed.
	m = inConfigForm()
	if _, err := parseRaw(t, m); err != nil {
		t.Fatal(err)
	}
}

// Rule 8: a placeholder naming an undeclared value.
func TestConfigRefusesAPlaceholderNamingAnUndeclaredValue(t *testing.T) {
	m := inConfigForm()
	resourceOf(m, "configuration")["content"] = "font = ${config:font-size}\nwidth = ${config:width}\n" +
		"from = ${config:sender}\ncolour = ${config:colour}\n"
	refused(t, m, "${config:colour}", "declares no such value")
}

// Rule 9: a reload-on or restart-on naming a file the module does not declare.
func TestConfigRefusesAReloadOrRestartOnNamingAnUndeclaredFile(t *testing.T) {
	m := inConfigForm()
	resourceOf(m, "notifier")["reload-on"] = []any{"configuration", "dunstrc"}
	refused(t, m, "reload-on", `"dunstrc"`, "declares no such")
	m = inConfigForm()
	resourceOf(m, "notifier")["restart-on"] = []any{"rule"}
	refused(t, m, "restart-on", `"rule"`)
	// Another module's file, and one the mesh makes for the module, are not the module's to declare.
	m = inConfigForm()
	resourceOf(m, "notifier")["restart-on"] = []any{"rules", "resolver.fact-zones", "secret-mail", "composed-jails"}
	if _, err := parseRaw(t, m); err != nil {
		t.Fatalf("refused: %v", err)
	}
}

// Rule 10: a moved module's mergeable file not naming its keys under takes-config.
func TestConfigRefusesAMergeableFileNotNamingItsKeys(t *testing.T) {
	m := inConfigForm()
	delete(resourceOf(m, "rules"), "takes-config")
	// position and theme are then placed nowhere; say they are read at runtime so only the file's rule speaks.
	declaration(m, "position")["runtime"] = true
	declaration(m, "theme")["runtime"] = true
	refused(t, m, "rules", "names no takes-config")
}

// Rule 11: a mesh word, puid or pgid in takes-config.
func TestConfigRefusesAMeshWordOrAnAccountFactInTakesConfig(t *testing.T) {
	for _, word := range []string{"ports", "expose", "reach", "endpoints", "places", "accesses", "networks", "puid", "pgid"} {
		m := inConfigForm()
		resourceOf(m, "rules")["takes-config"] = []any{"position", "theme", word}
		refused(t, m, `"`+word+`"`, "takes-config")
	}
}

// A module uses one form or the other, never both.
func TestAManifestMixingTheConfigAndSettingsFormsIsRefused(t *testing.T) {
	m := inConfigForm()
	resourceOf(m, "configuration")["content"] = "font = ${config:font-size}\nwidth = ${setting:width}\nfrom = ${config:sender}\n"
	refused(t, m, "mixes", "${setting:", "config")

	m = inConfigForm()
	delete(resourceOf(m, "rules"), "takes-config")
	resourceOf(m, "rules")["takes-settings"] = []any{"position", "theme"}
	refused(t, m, "mixes", "takes-settings")

	m = inConfigForm()
	m["settings"] = map[string]any{"colour": map[string]any{"kind": "preference", "default": "red", "why": "red"}}
	refused(t, m, "mixes", "settings")
}

// The settings form keeps its own declaration; the config form's has no kind or why.
func TestEachFormKeepsItsOwnDeclaration(t *testing.T) {
	m := inConfigForm()
	declaration(m, "width")["why"] = "fits a title"
	refused(t, m, `"width"`, "why")

	err := parsed(t, Manifest{Module: "notifier",
		Settings: map[string]SettingDeclaration{"width": {Kind: KindPreference, Default: float64(250),
			Why: "fits a title", Type: "number"}},
		Resources: []map[string]any{{"id": "c", "type": "file", "path": "/x", "content": "${setting:width}"}}})
	if err == nil || !strings.Contains(err.Error(), "under config") {
		t.Fatalf("a typed value under settings: %v", err)
	}
}

// What the mesh holds is what was written: a module in the config form is written back in it, and read again
// the same.
func TestAConfigManifestIsWrittenBackInItsOwnForm(t *testing.T) {
	m, err := parseRaw(t, inConfigForm())
	if err != nil {
		t.Fatal(err)
	}
	raw, err := json.Marshal(m)
	if err != nil {
		t.Fatal(err)
	}
	for _, said := range []string{`"config":`, `${config:font-size}`, `"takes-config":`, `"required":true`} {
		if !strings.Contains(string(raw), said) {
			t.Fatalf("written back without %s: %s", said, raw)
		}
	}
	for _, unsaid := range []string{`"settings":`, `${setting:`, `"takes-settings"`, `"kind"`, `"why"`, `"default":null`} {
		if strings.Contains(string(raw), unsaid) {
			t.Fatalf("written back with %s: %s", unsaid, raw)
		}
	}
	again, err := ParseManifest(raw)
	if err != nil {
		t.Fatal(err)
	}
	twice, _ := json.Marshal(again)
	if !bytes.Equal(raw, twice) {
		t.Fatalf("read again it is written\n%s\nwhere it was\n%s", twice, raw)
	}
}

// A module in the settings form is written back byte for byte as before.
func TestASettingsManifestIsWrittenBackAsBefore(t *testing.T) {
	d := SettingDeclaration{Kind: KindPreference, Default: float64(10), Why: "readable"}
	raw, err := json.Marshal(d)
	if err != nil {
		t.Fatal(err)
	}
	if string(raw) != `{"kind":"preference","default":10,"why":"readable"}` {
		t.Fatalf("written as %s", raw)
	}
}

// settingsDunst is the dunst module as it is written today; configDunst the same module rewritten from settings to
// config.
const settingsDunst = `{"module": "dunst", "version": "1",
  "settings": {
    "font-size": {"kind": "preference", "default": 10, "why": "10 points of Inter reads well on a screen of about 100 DPI"},
    "width": {"kind": "preference", "default": 250, "why": "250 pixels fits a title of about forty characters at 10 points"}
  },
  "resources": [
    {"id": "package", "type": "package", "package": "dunst"},
    {"id": "configuration", "type": "file", "path": "/home/me/.config/dunst/dunstrc", "mode": "0644",
     "content": "[global]\n    font = Inter ${setting:font-size}\n    width = ${setting:width}\n"},
    {"id": "rules", "type": "file", "path": "/home/me/.config/dunst/rules.json", "merge": "json",
     "takes-settings": [], "content": "{\"urgency\": \"low\"}\n"},
    {"id": "notifier", "type": "service", "unit": "dunst.service", "reload-on": ["configuration"]}
  ]}`

const configDunst = `{"module": "dunst", "version": "1",
  "config": {
    "font-size": {"type": "number", "description": "the font size of a notification, in points", "minimum": 6,
                  "maximum": 40, "default": 10},
    "width": {"type": "number", "description": "the width of a notification, in pixels", "minimum": 100,
              "default": 250}
  },
  "resources": [
    {"id": "package", "type": "package", "package": "dunst"},
    {"id": "configuration", "type": "file", "path": "/home/me/.config/dunst/dunstrc", "mode": "0644",
     "content": "[global]\n    font = Inter ${config:font-size}\n    width = ${config:width}\n"},
    {"id": "rules", "type": "file", "path": "/home/me/.config/dunst/rules.json", "merge": "json",
     "takes-config": [], "content": "{\"urgency\": \"low\"}\n"},
    {"id": "notifier", "type": "service", "unit": "dunst.service", "reload-on": ["configuration"]}
  ]}`

// ${config:<key>} fills exactly as ${setting:<key>} does: the module rewritten from settings to config composes
// to the same bytes, with no layer, with the node's, and with the mesh's under the node's.
func TestAModuleRewrittenFromSettingsToConfigComposesByteIdentically(t *testing.T) {
	composed := func(manifest string, layers []Layer) []byte {
		t.Helper()
		m, err := ParseManifest([]byte(manifest))
		if err != nil {
			t.Fatal(err)
		}
		r := anAdoptedAnchor()
		r.Modules = append(r.Modules, m)
		with := anchorRendering(false)
		if layers != nil {
			with.Settings["dunst"] = layers
		}
		c, err := r.Compose(with)
		if err != nil {
			t.Fatal(err)
		}
		if why, left := c.LeftOut["dunst"]; left {
			t.Fatalf("dunst was left out: %s", why)
		}
		raw, err := json.Marshal(c)
		if err != nil {
			t.Fatal(err)
		}
		return raw
	}
	for _, layers := range [][]Layer{
		nil,
		{{From: "anchor", Values: map[string]any{"font-size": float64(13)}}},
		{{From: MeshWideLayer, Values: map[string]any{"width": float64(300)}},
			{From: "anchor", Values: map[string]any{"font-size": float64(12), "width": float64(320)}}},
	} {
		was, is := composed(settingsDunst, layers), composed(configDunst, layers)
		if !bytes.Equal(was, is) {
			t.Fatalf("composed differently with %v:\nsettings: %s\nconfig:   %s", layers, was, is)
		}
		if !strings.Contains(string(is), "font = Inter 1") || strings.Contains(string(is), "${config:") {
			t.Fatalf("not filled: %s", is)
		}
	}
}

// A key a mergeable file takes is a config value like every other: one not declared under config is refused by
// name (ADR 0348 §4, review of mesh-controller#320).
func TestConfigRefusesATakesConfigKeyNotDeclared(t *testing.T) {
	m := inConfigForm()
	resourceOf(m, "rules")["takes-config"] = []any{"position", "theme", "urgency"}
	refused(t, m, `"urgency"`, "takes-config", "declares no such value under config")
}

// A required value nothing sets is refused at composition in the config form's words: ${config:<key>} and the
// config verb, never `settings set` (review of mesh-controller#320). The settings form's words are unchanged.
func TestAnUnsetRequiredValueIsRefusedInTheConfigFormsWords(t *testing.T) {
	m, err := parseRaw(t, inConfigForm())
	if err != nil {
		t.Fatal(err)
	}
	r := anAdoptedAnchor()
	r.Modules = append(r.Modules, m)
	composed, err := r.Compose(anchorRendering(false))
	if err != nil {
		t.Fatal(err)
	}
	why, left := composed.LeftOut["notifier"]
	if !left {
		t.Fatal("a module whose required value nothing sets was not left out")
	}
	for _, said := range []string{"${config:sender}", `required config value "sender"`, "config verb"} {
		if !strings.Contains(why, said) {
			t.Fatalf("left out without %q: %s", said, why)
		}
	}
	for _, unsaid := range []string{"${setting:", "settings set"} {
		if strings.Contains(why, unsaid) {
			t.Fatalf("left out in the settings form's words (%q): %s", unsaid, why)
		}
	}
	var unset *UnsetSettingError
	if err := unsetInConfigWords(settingInto(map[string]any{"type": "file", "content": "${setting:sender}"}, nil,
		"notifier"), m); !errors.As(err, &unset) || unset.Setting != "sender" {
		t.Fatalf("not typed as a value nobody gave: %v", err)
	}

	settingsForm := notifier()
	settingsForm.Resources[0]["content"] = "from = ${setting:domain}\n"
	err = unsetInConfigWords(settingInto(settingsForm.Resources[0], nil, "notifier"), settingsForm)
	if err == nil || !strings.Contains(err.Error(), "`settings set notifier <file>`") {
		t.Fatalf("the settings form's refusal changed: %v", err)
	}
}