package engine

import (
	"errors"
	"testing"
)

func TestResolutionAuditsOrdinaryListFields(t *testing.T) {
	type item struct {
		Count   int    `yaml:"count"`
		Enabled bool   `yaml:"enabled"`
		Nested  []*int `yaml:"nested"`
	}
	type config struct {
		Items []item `yaml:"items"`
	}
	for _, test := range []struct {
		name          string
		other, resize bool
		wantPath      string
	}{
		{name: "covered field"},
		{name: "uncovered field", other: true, wantPath: "/items/0/enabled"},
		{name: "length change", resize: true, wantPath: "/items"},
	} {
		t.Run(test.name, func(t *testing.T) {
			result, err := testLoad(Bytes("items", []byte("items: [{count: 3, enabled: true, nested: [null]}]\n")), Options[config]{Definition: Definition[config]{
				Resolve: func(value *config, r *Resolution) error {
					value.Items[0].Count = 0
					r.RecordNormalization(Keys("items").Index(0).Key("count"), "clear count")
					if test.other {
						value.Items[0].Enabled = false
					}
					if test.resize {
						value.Items = append(value.Items, item{})
					}
					return nil
				},
			}})
			if test.wantPath == "" {
				if err != nil || result.Config.Items[0].Count != 0 {
					t.Fatalf("result = %#v, error = %v", result, err)
				}
				return
			}
			var failure *LoadError
			if !errors.As(err, &failure) {
				t.Fatalf("error = %v", err)
			}
			found := false
			for _, diagnostic := range failure.Diagnostics() {
				if diagnostic.Code == CodeResolveUnrecordedChange && diagnostic.Path.String() == test.wantPath {
					found = true
				}
			}
			if !found {
				t.Fatalf("diagnostics = %#v", failure.Diagnostics())
			}
		})
	}
}

func TestResolutionComparisonKeepsDiffAtomic(t *testing.T) {
	before := parseCompositionDocument(t, "before", "items: [{values: [true, null]}]")
	after := parseCompositionDocument(t, "after", "items: [{values: [false, 0]}]")
	deltas := compareResolutionValues(before, after)
	if len(deltas) != 2 || deltas[0].path.String() != "/items/0/values/0" || deltas[1].path.String() != "/items/0/values/1" {
		t.Fatalf("resolution deltas = %#v", deltas)
	}
	atomic := compareConfigurationValues(before, after)
	if len(atomic) != 1 || atomic[0].path.String() != "/items" {
		t.Fatalf("atomic deltas = %#v", atomic)
	}
}

func TestResolutionAuditsRegisteredCollectionChanges(t *testing.T) {
	type item struct {
		ID    string `yaml:"id"`
		Value string `yaml:"value"`
	}
	type config struct {
		Items []item `yaml:"items"`
	}
	for _, test := range []struct {
		name                    string
		move, container, rename bool
		wantPath                string
	}{
		{name: "field edit"},
		{name: "uncovered move", move: true, wantPath: "/items"},
		{name: "covered move", move: true, container: true},
		{name: "identity replacement", rename: true, wantPath: "/items"},
	} {
		t.Run(test.name, func(t *testing.T) {
			definition := Definition[config]{Resolve: func(value *config, r *Resolution) error {
				value.Items[0].Value = "changed"
				if test.move {
					value.Items[0], value.Items[1] = value.Items[1], value.Items[0]
				}
				if test.rename {
					value.Items[0].ID = "new"
				}
				index := 0
				if test.move {
					index = 1
				}
				r.RecordNormalization(Keys("items").Index(index).Key("value"), "change value")
				if test.container {
					r.RecordNormalization(Keys("items"), "reorder")
				}
				return nil
			}}
			definition = DefinitionWithSequenceIdentityRegistrations(definition, []SequenceIdentityRegistrationInput{{ExactPath: pathPointer(Keys("items")), IdentityFields: []string{"id"}}})
			result, err := testLoad(Bytes("items", []byte("items: [{id: a, value: old}, {id: b, value: other}]\n")), Options[config]{Definition: definition})
			if test.wantPath == "" {
				if err != nil {
					t.Fatal(err)
				}
				if test.move {
					for _, snapshot := range result.history.resolutionPayload.snapshots {
						if snapshot.change.Path.String() == "/items/1/value" && (snapshot.before == nil || snapshot.before.Text != "old") {
							t.Fatalf("paired before = %#v", snapshot.before)
						}
					}
				}
				return
			}
			var failure *LoadError
			if !errors.As(err, &failure) {
				t.Fatalf("error = %v", err)
			}
			found := false
			for _, diagnostic := range failure.Diagnostics() {
				if diagnostic.Code == CodeResolveUnrecordedChange && diagnostic.Path.String() == test.wantPath {
					found = true
				}
			}
			if !found {
				t.Fatalf("diagnostics = %#v", failure.Diagnostics())
			}
		})
	}
}

func TestRegisteredResolutionFallbackAndHelperTarget(t *testing.T) {
	type item struct {
		ID    string `yaml:"id"`
		Value string `yaml:"value"`
	}
	type config struct {
		Items []item `yaml:"items"`
	}
	registration := []SequenceIdentityRegistrationInput{{ExactPath: pathPointer(Keys("items")), IdentityFields: []string{"id"}}}
	makeDefinition := func(resolve func(*config, *Resolution) error) Definition[config] {
		return DefinitionWithSequenceIdentityRegistrations(Definition[config]{Defaults: func() config { return config{Items: []item{{ID: "a"}, {ID: "a"}}} }, Resolve: resolve}, registration)
	}
	_, err := testLoad(NoSource(), Options[config]{Definition: makeDefinition(func(value *config, r *Resolution) error {
		value.Items[1].ID = "b"
		r.RecordNormalization(Keys("items"), "repair identities")
		return nil
	})})
	if err != nil {
		t.Fatalf("repair rejected: %v", err)
	}
	_, err = testLoad(NoSource(), Options[config]{Definition: makeDefinition(func(*config, *Resolution) error { return nil })})
	if err == nil {
		t.Fatal("invalid final identities accepted")
	}
	definition := DefinitionWithSequenceIdentityRegistrations(Definition[config]{Resolve: func(value *config, r *Resolution) error {
		Normalize(r, Keys("items").Index(0).Key("value"), &value.Items[0].Value, "changed", "normalize")
		value.Items[0], value.Items[1] = value.Items[1], value.Items[0]
		r.RecordNormalization(Keys("items"), "reorder")
		return nil
	}}, registration)
	_, err = testLoad(Bytes("items", []byte("items: [{id: a, value: first}, {id: b, value: second}]\n")), Options[config]{Definition: definition})
	var failure *LoadError
	if !errors.As(err, &failure) {
		t.Fatalf("helper error = %v", err)
	}
	found := false
	for _, diagnostic := range failure.Diagnostics() {
		if diagnostic.Code == CodeResolveInvalidTarget && diagnostic.Path.String() == "/items/0/value" {
			found = true
		}
	}
	if !found {
		t.Fatalf("diagnostics = %#v", failure.Diagnostics())
	}
}