package processor

import (
	"strings"
	"testing"

	"cook/utils"
)

// TestRealWorldGameXML tests with game-like XML structure
func TestRealWorldGameXML(t *testing.T) {
	original := `<?xml version="1.0" encoding="utf-8"?>
<Items>
  <Item name="Fiber" identifier="Item_Fiber" category="Resource">
    <Icon texture="Items/Fiber.png" />
    <Weight value="0.01" />
    <MaxStack value="1000" />
    <Description text="Soft plant fibers useful for crafting." />
  </Item>
  <Item name="Wood" identifier="Item_Wood" category="Resource">
    <Icon texture="Items/Wood.png" />
    <Weight value="0.05" />
    <MaxStack value="500" />
    <Description text="Basic building material." />
  </Item>
</Items>`

	// Parse
	origElem, err := parseXMLWithPositions(original)
	if err != nil {
		t.Fatalf("Failed to parse: %v", err)
	}

	// Modify: Double all MaxStack values and change Wood weight
	modElem := deepCopyXMLElement(origElem)

	// Fiber MaxStack: 1000 → 2000
	fiberItem := modElem.Children[0]
	fiberMaxStack := fiberItem.Children[2]
	valueAttr := fiberMaxStack.Attributes["value"]
	valueAttr.Value = "2000"
	fiberMaxStack.Attributes["value"] = valueAttr

	// Wood MaxStack: 500 → 1000
	woodItem := modElem.Children[1]
	woodMaxStack := woodItem.Children[2]
	valueAttr2 := woodMaxStack.Attributes["value"]
	valueAttr2.Value = "1000"
	woodMaxStack.Attributes["value"] = valueAttr2

	// Wood Weight: 0.05 → 0.10
	woodWeight := woodItem.Children[1]
	weightAttr := woodWeight.Attributes["value"]
	weightAttr.Value = "0.10"
	woodWeight.Attributes["value"] = weightAttr

	// Generate changes
	changes := findXMLChanges(origElem, modElem, "")

	if len(changes) != 3 {
		t.Fatalf("Expected 3 changes, got %d", len(changes))
	}

	// Apply
	commands := applyXMLChanges(changes)
	result, _ := utils.ExecuteModifications(commands, original)

	// Verify changes
	if !strings.Contains(result, `<MaxStack value="2000"`) {
		t.Errorf("Failed to update Fiber MaxStack")
	}
	if !strings.Contains(result, `<MaxStack value="1000"`) {
		t.Errorf("Failed to update Wood MaxStack")
	}
	if !strings.Contains(result, `<Weight value="0.10"`) {
		t.Errorf("Failed to update Wood Weight")
	}

	// Verify formatting preserved (check XML declaration and indentation)
	if !strings.HasPrefix(result, `<?xml version="1.0" encoding="utf-8"?>`) {
		t.Errorf("XML declaration not preserved")
	}
	if !strings.Contains(result, "\n  <Item") {
		t.Errorf("Indentation not preserved")
	}
}

// TestAddRemoveMultipleChildren tests adding and removing multiple elements
func TestAddRemoveMultipleChildren(t *testing.T) {
	original := `<inventory>
  <item name="sword" />
  <item name="shield" />
  <item name="potion" />
  <item name="scroll" />
</inventory>`

	// Parse
	origElem, err := parseXMLWithPositions(original)
	if err != nil {
		t.Fatalf("Failed to parse: %v", err)
	}

	// Remove middle two items, add a new one
	modElem := deepCopyXMLElement(origElem)

	// Remove shield and potion (indices 1 and 2)
	modElem.Children = []*XMLElement{
		modElem.Children[0], // sword
		modElem.Children[3], // scroll
	}

	// Add a new item
	newItem := &XMLElement{
		Tag: "item",
		Attributes: map[string]XMLAttribute{
			"name": {Value: "helmet"},
		},
		Children: []*XMLElement{},
	}
	modElem.Children = append(modElem.Children, newItem)

	// Generate changes
	changes := findXMLChanges(origElem, modElem, "")

	// The algorithm compares by matching indices:
	// orig[0]=sword vs mod[0]=sword (no change)
	// orig[1]=shield vs mod[1]=scroll (treated as replace - shows as attribute changes)
	// orig[2]=potion vs mod[2]=helmet (treated as replace)
	// orig[3]=scroll (removed)
	// This is fine - the actual edits will be correct

	if len(changes) == 0 {
		t.Fatalf("Expected changes, got none")
	}

	// Apply
	commands := applyXMLChanges(changes)
	result, _ := utils.ExecuteModifications(commands, original)

	// Verify
	if strings.Contains(result, `name="shield"`) {
		t.Errorf("Shield not removed")
	}
	if strings.Contains(result, `name="potion"`) {
		t.Errorf("Potion not removed")
	}
	if !strings.Contains(result, `name="sword"`) {
		t.Errorf("Sword incorrectly removed")
	}
	if !strings.Contains(result, `name="scroll"`) {
		t.Errorf("Scroll incorrectly removed")
	}
	if !strings.Contains(result, `name="helmet"`) {
		t.Errorf("Helmet not added")
	}
}

// TestModifyAttributesAndText tests changing both attributes and text content
func TestModifyAttributesAndText(t *testing.T) {
	original := `<weapon>
  <item type="sword" damage="10">Iron Sword</item>
  <item type="axe" damage="15">Battle Axe</item>
</weapon>`

	// Parse
	origElem, err := parseXMLWithPositions(original)
	if err != nil {
		t.Fatalf("Failed to parse: %v", err)
	}

	// Modify both items
	modElem := deepCopyXMLElement(origElem)

	// First item: change damage and text
	item1 := modElem.Children[0]
	dmgAttr := item1.Attributes["damage"]
	dmgAttr.Value = "20"
	item1.Attributes["damage"] = dmgAttr
	item1.Text = "Steel Sword"

	// Second item: change damage and type
	item2 := modElem.Children[1]
	dmgAttr2 := item2.Attributes["damage"]
	dmgAttr2.Value = "30"
	item2.Attributes["damage"] = dmgAttr2
	typeAttr := item2.Attributes["type"]
	typeAttr.Value = "greataxe"
	item2.Attributes["type"] = typeAttr

	// Generate and apply changes
	changes := findXMLChanges(origElem, modElem, "")
	commands := applyXMLChanges(changes)
	result, _ := utils.ExecuteModifications(commands, original)

	// Verify
	if !strings.Contains(result, `damage="20"`) {
		t.Errorf("First item damage not updated")
	}
	if !strings.Contains(result, "Steel Sword") {
		t.Errorf("First item text not updated")
	}
	if !strings.Contains(result, `damage="30"`) {
		t.Errorf("Second item damage not updated")
	}
	if !strings.Contains(result, `type="greataxe"`) {
		t.Errorf("Second item type not updated")
	}
	if strings.Contains(result, "Iron Sword") {
		t.Errorf("Old text still present")
	}
}

// TestSelfClosingTagPreservation tests that self-closing tags work correctly
func TestSelfClosingTagPreservation(t *testing.T) {
	original := `<root>
  <item name="test" />
  <empty></empty>
</root>`

	// Parse
	origElem, err := parseXMLWithPositions(original)
	if err != nil {
		t.Fatalf("Failed to parse: %v", err)
	}

	// Modify first item's attribute
	modElem := deepCopyXMLElement(origElem)
	item := modElem.Children[0]
	nameAttr := item.Attributes["name"]
	nameAttr.Value = "modified"
	item.Attributes["name"] = nameAttr

	// Generate and apply changes
	changes := findXMLChanges(origElem, modElem, "")
	commands := applyXMLChanges(changes)
	result, _ := utils.ExecuteModifications(commands, original)

	// Verify the change was made
	if !strings.Contains(result, `name="modified"`) {
		t.Errorf("Attribute not updated: %s", result)
	}
}

// TestNumericAttributeModification tests numeric attribute changes
func TestNumericAttributeModification(t *testing.T) {
	original := `<stats health="100" mana="50" stamina="75.5" />`

	// Parse
	origElem, err := parseXMLWithPositions(original)
	if err != nil {
		t.Fatalf("Failed to parse: %v", err)
	}

	// Double all numeric values
	modElem := deepCopyXMLElement(origElem)

	// Helper to modify numeric attributes
	modifyNumericAttr := func(attrName string, multiplier float64) {
		if attr, exists := modElem.Attributes[attrName]; exists {
			if val, ok := parseNumeric(attr.Value); ok {
				attr.Value = formatNumeric(val * multiplier)
				modElem.Attributes[attrName] = attr
			}
		}
	}

	modifyNumericAttr("health", 2.0)
	modifyNumericAttr("mana", 2.0)
	modifyNumericAttr("stamina", 2.0)

	// Generate and apply changes
	changes := findXMLChanges(origElem, modElem, "")

	if len(changes) != 3 {
		t.Fatalf("Expected 3 changes, got %d", len(changes))
	}

	commands := applyXMLChanges(changes)
	result, _ := utils.ExecuteModifications(commands, original)

	// Verify numeric changes
	if !strings.Contains(result, `health="200"`) {
		t.Errorf("Health not doubled: %s", result)
	}
	if !strings.Contains(result, `mana="100"`) {
		t.Errorf("Mana not doubled: %s", result)
	}
	if !strings.Contains(result, `stamina="151"`) {
		t.Errorf("Stamina not doubled: %s", result)
	}
}

// TestMinimalGitDiff verifies that only changed parts are modified
func TestMinimalGitDiff(t *testing.T) {
	original := `<config>
  <setting name="volume" value="50" />
  <setting name="brightness" value="75" />
  <setting name="contrast" value="100" />
</config>`

	// Parse
	origElem, err := parseXMLWithPositions(original)
	if err != nil {
		t.Fatalf("Failed to parse: %v", err)
	}

	// Change only brightness
	modElem := deepCopyXMLElement(origElem)
	brightnessItem := modElem.Children[1]
	valueAttr := brightnessItem.Attributes["value"]
	valueAttr.Value = "90"
	brightnessItem.Attributes["value"] = valueAttr

	// Generate changes
	changes := findXMLChanges(origElem, modElem, "")

	// Should be exactly 1 change
	if len(changes) != 1 {
		t.Fatalf("Expected exactly 1 change for minimal diff, got %d", len(changes))
	}

	if changes[0].OldValue != "75" || changes[0].NewValue != "90" {
		t.Errorf("Wrong change detected: %v", changes[0])
	}

	// Apply
	commands := applyXMLChanges(changes)
	result, _ := utils.ExecuteModifications(commands, original)

	// Calculate diff size (rough approximation)
	diffChars := len(changes[0].OldValue) + len(changes[0].NewValue)
	if diffChars > 10 {
		t.Errorf("Diff too large: %d characters changed (expected < 10)", diffChars)
	}

	// Verify only brightness changed
	if !strings.Contains(result, `value="50"`) {
		t.Errorf("Volume incorrectly modified")
	}
	if !strings.Contains(result, `value="90"`) {
		t.Errorf("Brightness not modified")
	}
	if !strings.Contains(result, `value="100"`) {
		t.Errorf("Contrast incorrectly modified")
	}
}