package parser_test

import (
	"testing"

	"git.sharkk.net/Sharkk/Mako/parser"
)

func TestBasicStructDefinition(t *testing.T) {
	input := `struct Person {
	name: string,
	age: number
}`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	if len(program.Statements) != 1 {
		t.Fatalf("expected 1 statement, got %d", len(program.Statements))
	}

	stmt, ok := program.Statements[0].(*parser.StructStatement)
	if !ok {
		t.Fatalf("expected StructStatement, got %T", program.Statements[0])
	}

	if stmt.Name != "Person" {
		t.Errorf("expected struct name 'Person', got %s", stmt.Name)
	}

	if len(stmt.Fields) != 2 {
		t.Fatalf("expected 2 fields, got %d", len(stmt.Fields))
	}

	// Test first field
	if stmt.Fields[0].Name != "name" {
		t.Errorf("expected field name 'name', got %s", stmt.Fields[0].Name)
	}
	if stmt.Fields[0].TypeHint == nil {
		t.Fatal("expected type hint for name field")
	}
	if stmt.Fields[0].TypeHint.Type != "string" {
		t.Errorf("expected type 'string', got %s", stmt.Fields[0].TypeHint.Type)
	}

	// Test second field
	if stmt.Fields[1].Name != "age" {
		t.Errorf("expected field name 'age', got %s", stmt.Fields[1].Name)
	}
	if stmt.Fields[1].TypeHint == nil {
		t.Fatal("expected type hint for age field")
	}
	if stmt.Fields[1].TypeHint.Type != "number" {
		t.Errorf("expected type 'number', got %s", stmt.Fields[1].TypeHint.Type)
	}
}

func TestEmptyStructDefinition(t *testing.T) {
	input := `struct Empty {}`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	if len(program.Statements) != 1 {
		t.Fatalf("expected 1 statement, got %d", len(program.Statements))
	}

	stmt, ok := program.Statements[0].(*parser.StructStatement)
	if !ok {
		t.Fatalf("expected StructStatement, got %T", program.Statements[0])
	}

	if stmt.Name != "Empty" {
		t.Errorf("expected struct name 'Empty', got %s", stmt.Name)
	}

	if len(stmt.Fields) != 0 {
		t.Errorf("expected 0 fields, got %d", len(stmt.Fields))
	}
}

func TestComplexStructDefinition(t *testing.T) {
	input := `struct Complex {
	id: number,
	name: string,
	active: bool,
	data: table,
	callback: function,
	optional: any
}`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	if len(program.Statements) != 1 {
		t.Fatalf("expected 1 statement, got %d", len(program.Statements))
	}

	stmt, ok := program.Statements[0].(*parser.StructStatement)
	if !ok {
		t.Fatalf("expected StructStatement, got %T", program.Statements[0])
	}

	expectedTypes := []string{"number", "string", "bool", "table", "function", "any"}
	expectedNames := []string{"id", "name", "active", "data", "callback", "optional"}

	if len(stmt.Fields) != len(expectedTypes) {
		t.Fatalf("expected %d fields, got %d", len(expectedTypes), len(stmt.Fields))
	}

	for i, field := range stmt.Fields {
		if field.Name != expectedNames[i] {
			t.Errorf("field %d: expected name '%s', got '%s'", i, expectedNames[i], field.Name)
		}
		if field.TypeHint == nil {
			t.Fatalf("field %d: expected type hint", i)
		}
		if field.TypeHint.Type != expectedTypes[i] {
			t.Errorf("field %d: expected type '%s', got '%s'", i, expectedTypes[i], field.TypeHint.Type)
		}
	}
}

func TestMethodDefinition(t *testing.T) {
	input := `struct Person {
	name: string,
	age: number
}

fn Person.getName(): string
	return self.name
end

fn Person.setAge(newAge: number)
	self.age = newAge
end`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	if len(program.Statements) != 3 {
		t.Fatalf("expected 3 statements, got %d", len(program.Statements))
	}

	// First statement: struct definition
	structStmt, ok := program.Statements[0].(*parser.StructStatement)
	if !ok {
		t.Fatalf("expected StructStatement, got %T", program.Statements[0])
	}
	if structStmt.Name != "Person" {
		t.Errorf("expected struct name 'Person', got %s", structStmt.Name)
	}

	// Second statement: getter method
	method1, ok := program.Statements[1].(*parser.MethodDefinition)
	if !ok {
		t.Fatalf("expected MethodDefinition, got %T", program.Statements[1])
	}
	if method1.StructName != "Person" {
		t.Errorf("expected struct name 'Person', got %s", method1.StructName)
	}
	if method1.MethodName != "getName" {
		t.Errorf("expected method name 'getName', got %s", method1.MethodName)
	}
	if method1.Function.ReturnType == nil {
		t.Fatal("expected return type for getName method")
	}
	if method1.Function.ReturnType.Type != "string" {
		t.Errorf("expected return type 'string', got %s", method1.Function.ReturnType.Type)
	}
	if len(method1.Function.Parameters) != 0 {
		t.Errorf("expected 0 parameters, got %d", len(method1.Function.Parameters))
	}

	// Third statement: setter method
	method2, ok := program.Statements[2].(*parser.MethodDefinition)
	if !ok {
		t.Fatalf("expected MethodDefinition, got %T", program.Statements[2])
	}
	if method2.StructName != "Person" {
		t.Errorf("expected struct name 'Person', got %s", method2.StructName)
	}
	if method2.MethodName != "setAge" {
		t.Errorf("expected method name 'setAge', got %s", method2.MethodName)
	}
	if method2.Function.ReturnType != nil {
		t.Errorf("expected no return type for setAge method, got %s", method2.Function.ReturnType.Type)
	}
	if len(method2.Function.Parameters) != 1 {
		t.Fatalf("expected 1 parameter, got %d", len(method2.Function.Parameters))
	}
	if method2.Function.Parameters[0].Name != "newAge" {
		t.Errorf("expected parameter name 'newAge', got %s", method2.Function.Parameters[0].Name)
	}
	if method2.Function.Parameters[0].TypeHint == nil {
		t.Fatal("expected type hint for newAge parameter")
	}
	if method2.Function.Parameters[0].TypeHint.Type != "number" {
		t.Errorf("expected parameter type 'number', got %s", method2.Function.Parameters[0].TypeHint.Type)
	}
}

func TestStructConstructor(t *testing.T) {
	input := `struct Person {
	name: string,
	age: number
}

person = Person{name = "John", age = 30}
empty = Person{}`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	if len(program.Statements) != 3 {
		t.Fatalf("expected 3 statements, got %d", len(program.Statements))
	}

	// Second statement: constructor with fields
	assign1, ok := program.Statements[1].(*parser.AssignStatement)
	if !ok {
		t.Fatalf("expected AssignStatement, got %T", program.Statements[1])
	}

	constructor1, ok := assign1.Value.(*parser.StructConstructorExpression)
	if !ok {
		t.Fatalf("expected StructConstructorExpression, got %T", assign1.Value)
	}

	if constructor1.StructName != "Person" {
		t.Errorf("expected struct name 'Person', got %s", constructor1.StructName)
	}

	if len(constructor1.Fields) != 2 {
		t.Fatalf("expected 2 fields, got %d", len(constructor1.Fields))
	}

	// Check name field
	nameKey, ok := constructor1.Fields[0].Key.(*parser.Identifier)
	if !ok {
		t.Fatalf("expected Identifier for name key, got %T", constructor1.Fields[0].Key)
	}
	if nameKey.Value != "name" {
		t.Errorf("expected key 'name', got %s", nameKey.Value)
	}
	testStringLiteral(t, constructor1.Fields[0].Value, "John")

	// Check age field
	ageKey, ok := constructor1.Fields[1].Key.(*parser.Identifier)
	if !ok {
		t.Fatalf("expected Identifier for age key, got %T", constructor1.Fields[1].Key)
	}
	if ageKey.Value != "age" {
		t.Errorf("expected key 'age', got %s", ageKey.Value)
	}
	testNumberLiteral(t, constructor1.Fields[1].Value, 30)

	// Third statement: empty constructor
	assign2, ok := program.Statements[2].(*parser.AssignStatement)
	if !ok {
		t.Fatalf("expected AssignStatement, got %T", program.Statements[2])
	}

	constructor2, ok := assign2.Value.(*parser.StructConstructorExpression)
	if !ok {
		t.Fatalf("expected StructConstructorExpression, got %T", assign2.Value)
	}

	if constructor2.StructName != "Person" {
		t.Errorf("expected struct name 'Person', got %s", constructor2.StructName)
	}

	if len(constructor2.Fields) != 0 {
		t.Errorf("expected 0 fields, got %d", len(constructor2.Fields))
	}
}

func TestNestedStructTypes(t *testing.T) {
	input := `struct Address {
	street: string,
	city: string
}

struct Person {
	name: string,
	address: Address
}

person = Person{
	name = "John",
	address = Address{street = "Main St", city = "NYC"}
}`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	if len(program.Statements) != 3 {
		t.Fatalf("expected 3 statements, got %d", len(program.Statements))
	}

	// Check Person struct has Address field type
	personStruct, ok := program.Statements[1].(*parser.StructStatement)
	if !ok {
		t.Fatalf("expected StructStatement, got %T", program.Statements[1])
	}

	addressField := personStruct.Fields[1]
	if addressField.Name != "address" {
		t.Errorf("expected field name 'address', got %s", addressField.Name)
	}
	if addressField.TypeHint.Type != "Address" {
		t.Errorf("expected field type 'Address', got %s", addressField.TypeHint.Type)
	}

	// Check nested constructor
	assign, ok := program.Statements[2].(*parser.AssignStatement)
	if !ok {
		t.Fatalf("expected AssignStatement, got %T", program.Statements[2])
	}

	personConstructor, ok := assign.Value.(*parser.StructConstructorExpression)
	if !ok {
		t.Fatalf("expected StructConstructorExpression, got %T", assign.Value)
	}

	// Check the nested Address constructor
	addressConstructor, ok := personConstructor.Fields[1].Value.(*parser.StructConstructorExpression)
	if !ok {
		t.Fatalf("expected nested StructConstructorExpression, got %T", personConstructor.Fields[1].Value)
	}

	if addressConstructor.StructName != "Address" {
		t.Errorf("expected nested struct name 'Address', got %s", addressConstructor.StructName)
	}

	if len(addressConstructor.Fields) != 2 {
		t.Errorf("expected 2 fields in nested constructor, got %d", len(addressConstructor.Fields))
	}
}

func TestStructIntegrationWithProgram(t *testing.T) {
	input := `struct Point {
	x: number,
	y: number
}

fn Point.distance(other: Point): number
	dx = self.x - other.x
	dy = self.y - other.y
	return (dx * dx + dy * dy)
end

p1 = Point{x = 0, y = 0}
p2 = Point{x = 3, y = 4}

if p1.distance(p2) then
	echo "Distance calculated"
end

for i = 1, 10 do
	point = Point{x = i, y = i * 2}
	echo point.x
end`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	if len(program.Statements) != 6 {
		t.Fatalf("expected 6 statements, got %d", len(program.Statements))
	}

	// Verify struct definition
	structStmt, ok := program.Statements[0].(*parser.StructStatement)
	if !ok {
		t.Fatalf("expected StructStatement, got %T", program.Statements[0])
	}
	if structStmt.Name != "Point" {
		t.Errorf("expected struct name 'Point', got %s", structStmt.Name)
	}

	// Verify method definition
	methodStmt, ok := program.Statements[1].(*parser.MethodDefinition)
	if !ok {
		t.Fatalf("expected MethodDefinition, got %T", program.Statements[1])
	}
	if methodStmt.StructName != "Point" {
		t.Errorf("expected struct name 'Point', got %s", methodStmt.StructName)
	}
	if methodStmt.MethodName != "distance" {
		t.Errorf("expected method name 'distance', got %s", methodStmt.MethodName)
	}

	// Verify constructors
	for i := 2; i <= 3; i++ {
		assign, ok := program.Statements[i].(*parser.AssignStatement)
		if !ok {
			t.Fatalf("statement %d: expected AssignStatement, got %T", i, program.Statements[i])
		}
		constructor, ok := assign.Value.(*parser.StructConstructorExpression)
		if !ok {
			t.Fatalf("statement %d: expected StructConstructorExpression, got %T", i, assign.Value)
		}
		if constructor.StructName != "Point" {
			t.Errorf("statement %d: expected struct name 'Point', got %s", i, constructor.StructName)
		}
	}

	// Verify if statement with method call
	ifStmt, ok := program.Statements[4].(*parser.IfStatement)
	if !ok {
		t.Fatalf("expected IfStatement, got %T", program.Statements[4])
	}
	callExpr, ok := ifStmt.Condition.(*parser.CallExpression)
	if !ok {
		t.Fatalf("expected CallExpression in if condition, got %T", ifStmt.Condition)
	}
	dotExpr, ok := callExpr.Function.(*parser.DotExpression)
	if !ok {
		t.Fatalf("expected DotExpression for method call, got %T", callExpr.Function)
	}
	if dotExpr.Key != "distance" {
		t.Errorf("expected method name 'distance', got %s", dotExpr.Key)
	}

	// Verify for loop with struct creation
	forStmt, ok := program.Statements[5].(*parser.ForStatement)
	if !ok {
		t.Fatalf("expected ForStatement, got %T", program.Statements[5])
	}
	if len(forStmt.Body) != 2 {
		t.Errorf("expected 2 statements in for body, got %d", len(forStmt.Body))
	}

	// Check struct constructor in loop
	loopAssign, ok := forStmt.Body[0].(*parser.AssignStatement)
	if !ok {
		t.Fatalf("expected AssignStatement in loop, got %T", forStmt.Body[0])
	}
	loopConstructor, ok := loopAssign.Value.(*parser.StructConstructorExpression)
	if !ok {
		t.Fatalf("expected StructConstructorExpression in loop, got %T", loopAssign.Value)
	}
	if loopConstructor.StructName != "Point" {
		t.Errorf("expected struct name 'Point' in loop, got %s", loopConstructor.StructName)
	}
}

func TestStructErrorCases(t *testing.T) {
	tests := []struct {
		name                   string
		input                  string
		expectedErrorSubstring string
	}{
		{
			name: "missing field type",
			input: `struct Person {
				name
			}`,
			expectedErrorSubstring: "struct fields require type annotation",
		},
		{
			name: "missing struct name",
			input: `struct {
				name: string
			}`,
			expectedErrorSubstring: "expected struct name",
		},
		{
			name: "missing opening brace",
			input: `struct Person
				name: string
			}`,
			expectedErrorSubstring: "expected '{' after struct name",
		},
		{
			name: "missing closing brace",
			input: `struct Person {
				name: string`,
			expectedErrorSubstring: "expected next token to be }, got end of file instead",
		},
		{
			name: "invalid field type",
			input: `struct Person {
				name: invalidtype
			}`,
			expectedErrorSubstring: "invalid type name 'invalidtype'",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			l := parser.NewLexer(tt.input)
			p := parser.NewParser(l)
			_ = p.ParseProgram()

			if !p.HasErrors() {
				t.Fatalf("expected parser errors, but got none")
			}

			errors := p.ErrorStrings()
			found := false
			for _, err := range errors {
				if containsSubstring(err, tt.expectedErrorSubstring) {
					found = true
					break
				}
			}

			if !found {
				t.Errorf("expected error containing '%s', got errors: %v", tt.expectedErrorSubstring, errors)
			}
		})
	}
}

func TestSingleLineStruct(t *testing.T) {
	input := `struct Person { name: string, age: number }`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	if len(program.Statements) != 1 {
		t.Fatalf("expected 1 statement, got %d", len(program.Statements))
	}

	stmt, ok := program.Statements[0].(*parser.StructStatement)
	if !ok {
		t.Fatalf("expected StructStatement, got %T", program.Statements[0])
	}

	if stmt.Name != "Person" {
		t.Errorf("expected struct name 'Person', got %s", stmt.Name)
	}

	if len(stmt.Fields) != 2 {
		t.Fatalf("expected 2 fields, got %d", len(stmt.Fields))
	}

	if stmt.Fields[0].Name != "name" || stmt.Fields[0].TypeHint.Type != "string" {
		t.Errorf("expected first field 'name: string', got '%s: %s'",
			stmt.Fields[0].Name, stmt.Fields[0].TypeHint.Type)
	}

	if stmt.Fields[1].Name != "age" || stmt.Fields[1].TypeHint.Type != "number" {
		t.Errorf("expected second field 'age: number', got '%s: %s'",
			stmt.Fields[1].Name, stmt.Fields[1].TypeHint.Type)
	}
}

func TestStructString(t *testing.T) {
	input := `struct Person {
	name: string,
	age: number
}`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	stmt := program.Statements[0].(*parser.StructStatement)
	str := stmt.String()

	expected := "struct Person {\n\tname: string,\n\tage: number\n}"
	if str != expected {
		t.Errorf("expected string representation:\n%s\ngot:\n%s", expected, str)
	}
}

func TestMethodString(t *testing.T) {
	input := `struct Person {
	name: string
}

fn Person.getName(): string
	return self.name
end`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	method := program.Statements[1].(*parser.MethodDefinition)
	str := method.String()

	if !containsSubstring(str, "fn Person.getName") {
		t.Errorf("expected method string to contain 'fn Person.getName', got: %s", str)
	}
	if !containsSubstring(str, ": string") {
		t.Errorf("expected method string to contain return type, got: %s", str)
	}
}

func TestConstructorString(t *testing.T) {
	input := `struct Person {
	name: string,
	age: number
}

person = Person{name = "John", age = 30}`

	l := parser.NewLexer(input)
	p := parser.NewParser(l)
	program := p.ParseProgram()
	checkParserErrors(t, p)

	assign := program.Statements[1].(*parser.AssignStatement)
	constructor := assign.Value.(*parser.StructConstructorExpression)
	str := constructor.String()

	expected := `Person{name = "John", age = 30.00}`
	if str != expected {
		t.Errorf("expected constructor string:\n%s\ngot:\n%s", expected, str)
	}
}