package ckconfig

import (
	"bytes"
	"context"
	"reflect"
	"strconv"
	"strings"
	"testing"
)

func TestConfigScopeDiscoveryOrdersAndDeduplicatesCapabilities(t *testing.T) {
	app, err := New(Identity{Name: "example"})
	if err != nil {
		t.Fatal(err)
	}
	newContextCalls := 0
	acquireCalls := 0
	suite := ConfigSuite[struct{}]{
		NewContext: func() struct{} { newContextCalls++; return struct{}{} },
		Scopes: []ConfigScope[struct{}]{
			{Name: "zeta", Operations: []ConfigOperation{ConfigExplain, ConfigShow, ConfigExplain}, Acquire: func(context.Context, ConfigRequest, struct{}) (Acquired[ConfigView], error) {
				acquireCalls++
				return Acquired[ConfigView]{}, nil
			}},
			{Name: "promptkit", Operations: []ConfigOperation{ConfigSources}, Acquire: noopConfigAcquire[struct{}]},
			{Name: "app", Operations: []ConfigOperation{ConfigShow, ConfigValidate, ConfigShow}, Acquire: func(context.Context, ConfigRequest, struct{}) (Acquired[ConfigView], error) {
				acquireCalls++
				return Acquired[ConfigView]{}, nil
			}},
			{Name: "metadata", Summary: "No provider is required."},
		},
	}
	normalized, err := normalizeConfigSuite(suite)
	if err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(normalized.Scopes[0].Operations, []ConfigOperation{ConfigShow, ConfigExplain}) || !reflect.DeepEqual(normalized.Scopes[2].Operations, []ConfigOperation{ConfigValidate, ConfigShow}) {
		t.Fatalf("normalized capabilities = %#v", normalized.Scopes)
	}
	if err := RegisterConfig(app, suite); err != nil {
		t.Fatal(err)
	}

	var textOutput bytes.Buffer
	outcome := app.Execute(context.Background(), []string{"config", "scopes"}, Streams{Out: &textOutput})
	if outcome.Kind != OutcomeSuccess {
		t.Fatalf("text inventory outcome = %#v", outcome)
	}
	wantText := "app: validate, show\npromptkit: sources\nmetadata:\nzeta: show, explain\n"
	if textOutput.String() != wantText {
		t.Fatalf("text inventory = %q, want %q", textOutput.String(), wantText)
	}

	var yamlOutput bytes.Buffer
	outcome = app.Execute(context.Background(), []string{"config", "scopes", "--format", "yaml"}, Streams{Out: &yamlOutput})
	if outcome.Kind != OutcomeSuccess {
		t.Fatalf("YAML inventory outcome = %#v", outcome)
	}
	if got := yamlOutput.String(); !strings.Contains(got, "scopes:") || strings.Index(got, "name: app") > strings.Index(got, "name: promptkit") || !strings.Contains(got, "operations: []") {
		t.Fatalf("YAML inventory = %q", got)
	}
	outcome = app.Execute(context.Background(), []string{"config", "scopes", "--help"}, Streams{})
	if outcome.Kind != OutcomeSuccess {
		t.Fatalf("scope help outcome = %#v", outcome)
	}
	outcome = app.Execute(context.Background(), []string{"config", "scopes", "--format", "json"}, Streams{})
	if outcome.Kind != OutcomeUsage {
		t.Fatalf("invalid format outcome = %#v", outcome)
	}
	if newContextCalls != 0 || acquireCalls != 0 {
		t.Fatalf("discovery called runtime callbacks: NewContext=%d Acquire=%d", newContextCalls, acquireCalls)
	}
}

func TestConfigInputDefaultsToAppAndRetainsAbsentSelections(t *testing.T) {
	suite := ConfigSuite[struct{}]{Scopes: []ConfigScope[struct{}]{{Name: "app"}}}
	prepared, err := prepareInput(CommandSpec[configInput[struct{}]]{Flags: configInputFlags(suite, "yaml")}, make([][]string, 4), nil, true)
	if err != nil {
		t.Fatal(err)
	}
	input := prepared.build()
	if input.Scope != "app" || input.Format != "yaml" || input.Selection.Config.Set || input.Selection.Overlay.Set {
		t.Fatalf("configuration defaults = %#v", input)
	}
}

func TestRegisterConfigOwnsPreparedScopeAndSelectorMetadata(t *testing.T) {
	type selectorInput struct{ Region Supplied[string] }
	var acquired selectorInput
	suite := ConfigSuite[selectorInput]{
		Selectors: []Selector[selectorInput]{{
			Binding: ValueFlag[selectorInput](FlagMeta{Name: "region"}, nil, parseString, func(input *selectorInput, value Supplied[string]) { input.Region = value }),
			Scopes:  []string{"app"},
		}},
		Scopes: []ConfigScope[selectorInput]{{
			Name:       "app",
			Operations: []ConfigOperation{ConfigValidate},
			Acquire: func(_ context.Context, _ ConfigRequest, input selectorInput) (Acquired[ConfigView], error) {
				acquired = input
				return Acquired[ConfigView]{}, nil
			},
		}},
	}
	app, err := New(Identity{Name: "example"})
	if err != nil {
		t.Fatal(err)
	}
	if err := RegisterConfig(app, suite); err != nil {
		t.Fatal(err)
	}

	suite.Scopes[0].Name = "renamed"
	suite.Scopes[0].Operations[0] = ConfigShow
	suite.Selectors[0].Scopes[0] = "renamed"

	var inventory bytes.Buffer
	if result := app.Execute(context.Background(), []string{"config", "scopes"}, Streams{Out: &inventory}); result.Kind != OutcomeSuccess {
		t.Fatalf("scope inventory outcome = %#v", result)
	}
	if got := inventory.String(); got != "app: validate\n" {
		t.Fatalf("scope inventory after caller mutation = %q", got)
	}
	if result := app.Execute(context.Background(), []string{"config", "validate", "--scope=app", "--region=west"}, Streams{}); result.Kind != OutcomeSuccess {
		t.Fatalf("registered scope execution after caller mutation = %#v", result)
	}
	if acquired.Region != (Supplied[string]{Value: "west", Set: true}) {
		t.Fatalf("acquired selector after caller mutation = %#v", acquired)
	}
}

func TestRegisterConfigRejectsDuplicateSelectorNamesAndShorts(t *testing.T) {
	type selectorInput struct{ First, Second string }
	tests := []struct {
		name       string
		firstMeta  FlagMeta
		secondMeta FlagMeta
	}{
		{name: "name", firstMeta: FlagMeta{Name: "region", Short: "r"}, secondMeta: FlagMeta{Name: "region", Short: "g"}},
		{name: "short", firstMeta: FlagMeta{Name: "region", Short: "r"}, secondMeta: FlagMeta{Name: "group", Short: "r"}},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			app, err := New(Identity{Name: "example"})
			if err != nil {
				t.Fatal(err)
			}
			suite := ConfigSuite[selectorInput]{Selectors: []Selector[selectorInput]{
				{Binding: ValueFlag[selectorInput](test.firstMeta, nil, parseString, func(input *selectorInput, value Supplied[string]) { input.First = value.Value })},
				{Binding: ValueFlag[selectorInput](test.secondMeta, nil, parseString, func(input *selectorInput, value Supplied[string]) { input.Second = value.Value })},
			}}
			if err := RegisterConfig(app, suite); err == nil || !strings.Contains(err.Error(), "duplicate configuration selector flag") {
				t.Fatalf("RegisterConfig error = %v", err)
			}
		})
	}
}

func TestRegisterConfigRejectsInvalidSuitesAndCollisions(t *testing.T) {
	tests := []struct {
		name  string
		scope ConfigScope[struct{}]
		want  string
	}{
		{name: "empty name", scope: ConfigScope[struct{}]{}, want: "name must not be empty"},
		{name: "all name", scope: ConfigScope[struct{}]{Name: "all"}, want: "reserved"},
		{name: "unknown operation", scope: ConfigScope[struct{}]{Name: "app", Operations: []ConfigOperation{"diff"}}, want: "unknown operation"},
		{name: "missing acquisition", scope: ConfigScope[struct{}]{Name: "app", Operations: []ConfigOperation{ConfigValidate}}, want: "without an acquisition"},
	}
	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			app, _ := New(Identity{Name: "example"})
			err := RegisterConfig(app, ConfigSuite[struct{}]{Scopes: []ConfigScope[struct{}]{test.scope}})
			if err == nil || !strings.Contains(err.Error(), test.want) {
				t.Fatalf("RegisterConfig error = %v, want %q", err, test.want)
			}
		})
	}

	app, _ := New(Identity{Name: "example"})
	custom, err := NewCommand(CommandSpec[struct{}]{Name: "config", Run: func(Invocation, struct{}) Outcome { return Success() }})
	if err != nil {
		t.Fatal(err)
	}
	if err := app.Register(custom); err != nil {
		t.Fatal(err)
	}
	if err := RegisterConfig(app, ConfigSuite[struct{}]{}); err == nil {
		t.Fatal("replaced a pre-existing config command")
	}
}

func TestConfigSelectorPreflightAndScopedContextProjection(t *testing.T) {
	type selectorInput struct {
		Count   Supplied[int]
		Enabled Supplied[bool]
		Other   Supplied[int]
		Runtime string
	}
	baseContextCalls := 0
	checkCalls := 0
	var checked selectorInput
	countDefault := 9
	suite := ConfigSuite[selectorInput]{
		NewContext: func() selectorInput { baseContextCalls++; return selectorInput{Runtime: "invocation cache"} },
		Selectors: []Selector[selectorInput]{
			{Binding: ValueFlag[selectorInput](FlagMeta{Name: "count"}, &countDefault, strconv.Atoi, func(input *selectorInput, value Supplied[int]) { input.Count = value }), Scopes: []string{"app"}},
			{Binding: BoolFlag[selectorInput](FlagMeta{Name: "enabled"}, true, func(input *selectorInput, value Supplied[bool]) { input.Enabled = value }), Scopes: []string{"promptkit"}},
			{Binding: ValueFlag[selectorInput](FlagMeta{Name: "other"}, nil, strconv.Atoi, func(input *selectorInput, value Supplied[int]) { input.Other = value })},
		},
		CheckInput: func(_ Selection, input selectorInput) error { checkCalls++; checked = input; return nil },
		Scopes: []ConfigScope[selectorInput]{
			{Name: "app", Operations: []ConfigOperation{ConfigValidate}, Acquire: noopConfigAcquire[selectorInput]},
			{Name: "promptkit", Operations: []ConfigOperation{ConfigValidate}, Acquire: noopConfigAcquire[selectorInput]},
		},
	}
	normalized, err := normalizeConfigSuite(suite)
	if err != nil {
		t.Fatal(err)
	}
	preparedSuite := prepareConfigSuite(normalized)
	spec := CommandSpec[configInput[selectorInput]]{Flags: configInputFlags(normalized, "text")}
	prepared, err := prepareInput(spec, [][]string{{"all"}, {"text"}, {""}, nil, {"0"}, {"false"}, nil}, nil, true)
	if err != nil {
		t.Fatal(err)
	}
	input := prepared.build()
	scopeNames, err := preflightConfig(preparedSuite, input, ConfigValidate)
	if err != nil {
		t.Fatal(err)
	}
	if !reflect.DeepEqual(scopeNames, []string{"app", "promptkit"}) || checkCalls != 1 || checked.Count != (Supplied[int]{Value: 0, Set: true}) || checked.Enabled != (Supplied[bool]{Value: false, Set: true}) {
		t.Fatalf("preflight result=%v checked=%#v calls=%d", scopeNames, checked, checkCalls)
	}
	if !input.Selection.Config.Set || input.Selection.Config.Value != "" || input.Selection.Overlay.Set {
		t.Fatalf("configuration selection presence = %#v", input.Selection)
	}
	if baseContextCalls != 0 {
		t.Fatalf("NewContext called during preflight %d times", baseContextCalls)
	}

	contexts := contextsForScopes(preparedSuite, input, scopeNames)
	if baseContextCalls != 1 {
		t.Fatalf("NewContext calls = %d, want one", baseContextCalls)
	}
	if contexts["app"].Count != (Supplied[int]{Value: 0, Set: true}) || contexts["app"].Enabled != (Supplied[bool]{}) || contexts["app"].Other != (Supplied[int]{}) {
		t.Fatalf("app selectors = %#v", contexts["app"])
	}
	if contexts["promptkit"].Count != (Supplied[int]{}) || contexts["promptkit"].Enabled != (Supplied[bool]{Value: false, Set: true}) || contexts["promptkit"].Runtime != "invocation cache" {
		t.Fatalf("promptkit selectors = %#v", contexts["promptkit"])
	}
}

func TestConfigPreflightRejectsUnsupportedAggregateAndInapplicableSelector(t *testing.T) {
	type selectorInput struct{ Region Supplied[string] }
	newContextCalls := 0
	suite := ConfigSuite[selectorInput]{
		NewContext: func() selectorInput { newContextCalls++; return selectorInput{} },
		Selectors:  []Selector[selectorInput]{{Binding: ValueFlag[selectorInput](FlagMeta{Name: "region"}, nil, parseString, func(input *selectorInput, value Supplied[string]) { input.Region = value }), Scopes: []string{"promptkit"}}},
		Scopes: []ConfigScope[selectorInput]{
			{Name: "app", Operations: []ConfigOperation{ConfigValidate}, Acquire: noopConfigAcquire[selectorInput]},
			{Name: "promptkit", Operations: []ConfigOperation{ConfigShow}, Acquire: noopConfigAcquire[selectorInput]},
		},
	}
	normalized, err := normalizeConfigSuite(suite)
	if err != nil {
		t.Fatal(err)
	}
	preparedSuite := prepareConfigSuite(normalized)
	prepared, err := prepareInput(CommandSpec[configInput[selectorInput]]{Flags: configInputFlags(normalized, "text")}, [][]string{{"all"}, {"text"}, nil, nil, nil}, nil, true)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := preflightConfig(preparedSuite, prepared.build(), ConfigValidate); err == nil || !strings.Contains(err.Error(), "does not support validate") {
		t.Fatalf("unsupported aggregate error = %v", err)
	}
	if newContextCalls != 0 {
		t.Fatalf("unsupported aggregate created context %d times", newContextCalls)
	}

	prepared, err = prepareInput(CommandSpec[configInput[selectorInput]]{Flags: configInputFlags(normalized, "text")}, [][]string{{"app"}, {"text"}, nil, nil, {"west"}}, nil, true)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := preflightConfig(preparedSuite, prepared.build(), ConfigValidate); err == nil || !strings.Contains(err.Error(), "not applicable") {
		t.Fatalf("inapplicable selector error = %v", err)
	}
}

func noopConfigAcquire[C any](context.Context, ConfigRequest, C) (Acquired[ConfigView], error) {
	return Acquired[ConfigView]{}, nil
}

func TestRequiredConfigSelectorOnlyAppliesToSelectedScopes(t *testing.T) {
	app, _ := New(Identity{Name: "example"})
	calls := 0
	acquire := func(context.Context, ConfigRequest, string) (Acquired[ConfigView], error) {
		calls++
		return Acquired[ConfigView]{}, nil
	}
	err := RegisterConfig(app, ConfigSuite[string]{
		Selectors: []Selector[string]{{Scopes: []string{"app"}, Binding: ValueFlag[string](FlagMeta{Name: "campaign", Required: true}, nil, parseString, func(c *string, v Supplied[string]) { *c = v.Value })}},
		Scopes:    []ConfigScope[string]{{Name: "app", Operations: []ConfigOperation{ConfigValidate}, Acquire: acquire}, {Name: "promptkit", Operations: []ConfigOperation{ConfigValidate}, Acquire: acquire}},
	})
	if err != nil {
		t.Fatal(err)
	}
	for _, tc := range []struct {
		args  []string
		kind  OutcomeKind
		calls int
	}{
		{[]string{"--scope", "promptkit"}, OutcomeSuccess, 1},
		{nil, OutcomeUsage, 0},
		{[]string{"--scope", "all"}, OutcomeUsage, 0},
		{[]string{"--scope", "all", "--campaign", "spring"}, OutcomeSuccess, 2},
		{[]string{"--scope", "promptkit", "--campaign", "spring"}, OutcomeUsage, 0},
		{[]string{"--help"}, OutcomeSuccess, 0},
	} {
		calls = 0
		var out bytes.Buffer
		result := app.Execute(context.Background(), append([]string{"config", "validate"}, tc.args...), Streams{Out: &out})
		if result.Kind != tc.kind || calls != tc.calls {
			t.Fatalf("%v: result=%#v calls=%d", tc.args, result, calls)
		}
		if len(tc.args) > 0 && tc.args[0] == "--help" && !strings.Contains(out.String(), "required where applicable") {
			t.Fatalf("help=%q", out.String())
		}
	}
}

func TestUnknownConfigScopeReportsChoicesWithoutRuntimeWork(t *testing.T) {
	for _, tc := range []struct {
		names   []string
		scope   []string
		choices string
	}{
		{[]string{"promptkit"}, nil, "available: promptkit"},
		{[]string{"zeta", "alpha", "promptkit", "app"}, []string{"--scope", "unknown"}, "available: app, promptkit, alpha, zeta"},
	} {
		runtimeCalls := 0
		suite := ConfigSuite[struct{}]{NewContext: func() struct{} { runtimeCalls++; return struct{}{} }}
		for _, name := range tc.names {
			suite.Scopes = append(suite.Scopes, ConfigScope[struct{}]{Name: name, Operations: []ConfigOperation{ConfigValidate}, Acquire: func(context.Context, ConfigRequest, struct{}) (Acquired[ConfigView], error) {
				runtimeCalls++
				return Acquired[ConfigView]{}, nil
			}})
		}
		app, _ := New(Identity{Name: "example"})
		if err := RegisterConfig(app, suite); err != nil {
			t.Fatal(err)
		}
		var out, diagnostics bytes.Buffer
		result := app.Execute(context.Background(), append([]string{"config", "validate"}, tc.scope...), Streams{Out: &out, Err: &diagnostics})
		if result.Kind != OutcomeUsage || runtimeCalls != 0 || out.Len() != 0 || !strings.Contains(diagnostics.String(), tc.choices) {
			t.Fatalf("result=%#v calls=%d out=%q diagnostics=%q", result, runtimeCalls, out.String(), diagnostics.String())
		}
	}
}