package engine

import (
	"testing"

	"gitea.maximumdirect.net/eric/ConfigKit/internal/document"
)

func TestCLIOverrideRecordsTrackConcreteShapeChanges(t *testing.T) {
	t.Parallel()

	cases := []struct {
		name           string
		beforeText     string
		incomingText   string
		oldPath        Path
		introducedPath Path
	}{
		{
			name:           "mapping to sequence",
			beforeText:     "target: {'0': {old: true}}\n",
			incomingText:   "target: [{new: true}]\n",
			oldPath:        Keys("target", "0", "old"),
			introducedPath: Keys("target").Index(0).Key("new"),
		},
		{
			name:           "sequence to mapping",
			beforeText:     "target: [{old: true}]\n",
			incomingText:   "target: {'0': {new: true}}\n",
			oldPath:        Keys("target").Index(0).Key("old"),
			introducedPath: Keys("target", "0", "new"),
		},
	}
	for _, test := range cases {
		t.Run(test.name, func(t *testing.T) {
			before := parseDocumentForDecode(t, test.beforeText)
			incomingRoot := parseDocumentForDecode(t, test.incomingText)
			setOverrideTestDocumentSource(incomingRoot, "cli-source")
			incoming, _ := documentAtPath(incomingRoot, Keys("target"))
			origins := make(map[string]Origin)
			collectOverlayOrigins(origins, before, Path{}, LayerBase)
			records := overrideMetadataRecords(decodedConfiguration{final: before, origins: origins}, []preparedOverride{{
				path: Keys("target"), value: incoming, source: SourceInfo{ID: "cli-source"},
			}})
			if len(records) != 1 {
				t.Fatalf("override records = %#v", records)
			}
			record := records[0]
			if !containsConcreteDisplacement(record.displaced, test.oldPath) {
				t.Fatalf("displaced shape %s missing from %#v", test.oldPath, record.displaced)
			}
			introduced := findHistoryPathOrigin(record.introduced, test.introducedPath)
			if introduced == nil || introduced.origin.Layer != LayerCLI || len(introduced.origin.Locations) != 1 || introduced.origin.Locations[0].SourceID != "cli-source" {
				t.Fatalf("introduced shape %s has no CLI attribution: %#v", test.introducedPath, record.introduced)
			}
			application := historyApplication{
				layer: LayerCLI, path: Keys("target"), value: incoming,
				origin: overlayOrigin(LayerCLI, document.Location{SourceID: "cli-source"}),
			}
			builder := newHistoryBuilder()
			builder.setScratch(before)
			builder.observeCLIEvidence([]historyApplication{application}, records)
			model := builder.freeze()
			oldSelections := model.selectHistory(test.oldPath)
			if len(oldSelections) != 1 || oldSelections[0].role != historyRoleOperation || !oldSelections[0].before || oldSelections[0].after {
				t.Fatalf("displaced CLI shape %s = %#v", test.oldPath, oldSelections)
			}
			introducedSelections := model.selectHistory(test.introducedPath)
			introducedOperation := false
			for _, selection := range introducedSelections {
				introducedOperation = introducedOperation || selection.role == historyRoleOperation && !selection.before && selection.after
			}
			if !introducedOperation {
				t.Fatalf("introduced CLI shape %s selections = %#v", test.introducedPath, introducedSelections)
			}
		})
	}
}

func TestCLIHistoryEvidenceKeepsCheckpointsAndConditionalReconciliation(t *testing.T) {
	t.Parallel()

	structural := parseDocumentForDecode(t, "count: 7\nsettings: {a: 1, b: 2}\nitems: {old: value}\n")
	preCLI := parseDocumentForDecode(t, "count: '7'\nsettings: {a: 1, b: 2}\nitems: {old: value}\ndefaulted: 9\n")
	preOrigins := map[string]Origin{
		Keys("count").String():     {Layer: LayerBase, Locations: []Location{{SourceID: "input"}}},
		Keys("defaulted").String(): {Layer: LayerDefault},
	}
	countRoot := parseDocumentForDecode(t, "count: 7\n")
	settingsRoot := parseDocumentForDecode(t, "settings: {a: 1}\n")
	itemsRoot := parseDocumentForDecode(t, "items: []\n")
	setOverrideTestDocumentSource(countRoot, "cli-count")
	setOverrideTestDocumentSource(settingsRoot, "cli-settings")
	setOverrideTestDocumentSource(itemsRoot, "cli-items")
	countValue, _ := documentAtPath(countRoot, Keys("count"))
	settingsValue, _ := documentAtPath(settingsRoot, Keys("settings"))
	itemsValue, _ := documentAtPath(itemsRoot, Keys("items"))
	overrides := []preparedOverride{
		{path: Keys("count"), value: countValue, source: SourceInfo{ID: "cli-count"}},
		{path: Keys("settings"), value: settingsValue, source: SourceInfo{ID: "cli-settings"}},
		{path: Keys("items"), value: itemsValue, source: SourceInfo{ID: "cli-items"}},
	}
	records := overrideMetadataRecords(decodedConfiguration{final: preCLI, origins: preOrigins}, overrides)
	applications := make([]historyApplication, len(overrides))
	for index, override := range overrides {
		applications[index] = historyApplication{
			layer: LayerCLI, path: override.path, value: override.value,
			origin: overlayOrigin(LayerCLI, document.Location{SourceID: override.source.ID}),
		}
	}
	postCLI := parseDocumentForDecode(t, "count: '7'\nsettings: {a: 1, b: 2}\nitems: []\ndefaulted: 9\n")
	postOrigins := map[string]Origin{
		Keys("count").String():     {Layer: LayerCLI, Locations: []Location{{SourceID: "cli-count"}}},
		Keys("defaulted").String(): {Layer: LayerDefault},
	}

	builder := newHistoryBuilder()
	builder.setScratch(structural)
	builder.observePreCLICheckpoint(preCLI, preOrigins)
	builder.observeCLIEvidence(applications, records)
	builder.observePostCLICheckpoint(postCLI, postOrigins)
	preCount, _ := documentAtPath(preCLI, Keys("count"))
	postCount, _ := documentAtPath(postCLI, Keys("count"))
	preCount.Text = "producer mutation"
	postCount.Text = "producer mutation"
	model := builder.freeze()

	if model.preCLICheckpoint == nil || model.postCLICheckpoint == nil ||
		model.preCLICheckpoint.root == preCLI || model.postCLICheckpoint.root == postCLI ||
		len(model.cliPayloads) != 6 {
		t.Fatalf("checkpoint/CLI payload ownership = pre:%#v post:%#v CLI:%d", model.preCLICheckpoint, model.postCLICheckpoint, len(model.cliPayloads))
	}
	preValue, _ := documentAtPath(model.preCLICheckpoint.root, Keys("count"))
	postValue, _ := documentAtPath(model.postCLICheckpoint.root, Keys("count"))
	if preValue.Kind != document.String || preValue.Text != "7" || postValue.Kind != document.String || postValue.Text != "7" {
		t.Fatalf("typed checkpoint values = %#v / %#v", preValue, postValue)
	}

	count := model.selectHistory(Keys("count"))
	var sawPreDecoding, sawEqualCLI, sawPostDecoding bool
	for _, selection := range count {
		switch selection.phase {
		case historyPhasePreCLI:
			sawPreDecoding = selection.role == historyRoleCheckpoint && selection.before && selection.after &&
				selection.attribution.origin.Operation == ChangeDecoding && len(selection.attribution.reasons) != 0
		case historyPhaseCLI:
			sawEqualCLI = sawEqualCLI || selection.role == historyRoleOperation && selection.after
		case historyPhasePostCLI:
			sawPostDecoding = selection.role == historyRoleCheckpoint && selection.before && selection.after &&
				selection.attribution.origin.Layer == LayerCLI && selection.attribution.origin.Operation == ChangeDecoding
		}
	}
	if !sawPreDecoding || !sawEqualCLI || !sawPostDecoding {
		t.Fatalf("checkpoint and equal CLI selections = %#v", count)
	}
	if metadataHistoryRole(historyRoleCheckpoint) || !metadataHistoryRole(historyRoleOperation) {
		t.Fatal("typed reconciliation checkpoint leaked into metadata history roles")
	}

	defaulted := model.selectHistory(Keys("defaulted"))
	if len(defaulted) != 1 || defaulted[0].phase != historyPhasePreCLI || defaulted[0].before || !defaulted[0].after ||
		defaulted[0].attribution.origin.Layer != LayerDefault || len(defaulted[0].attribution.reasons) == 0 {
		t.Fatalf("retained default checkpoint = %#v", defaulted)
	}
	removed := model.selectHistory(Keys("items", "old"))
	if len(removed) != 1 || removed[0].phase != historyPhaseCLI || removed[0].role != historyRoleOperation || !removed[0].before || removed[0].after {
		t.Fatalf("whole-sequence CLI removal = %#v", removed)
	}
	untouched := model.selectHistory(Keys("settings", "b"))
	if len(untouched) != 0 {
		t.Fatalf("partial mapping CLI override attributed an untouched key: %#v", untouched)
	}
}

func containsConcreteDisplacement(displaced []displacedDefinition, path Path) bool {
	for _, candidate := range displaced {
		if sameConcreteHistoryPath(candidate.path, path) {
			return true
		}
	}
	return false
}

func findHistoryPathOrigin(introduced []historyPathOrigin, path Path) *historyPathOrigin {
	for index := range introduced {
		if sameConcreteHistoryPath(introduced[index].path, path) {
			return &introduced[index]
		}
	}
	return nil
}