// IDL语法规则
WHITESPACE = _{ " " | "\t" | "\r" | "\n" }
COMMENT = _{ "//" ~ (!"\n" ~ ANY)* ~ "\n" | "/*" ~ (!"*/" ~ ANY)* ~ "*/" }

// 基本字符定义
ASCII_ALPHA = _{ 'a'..'z' | 'A'..'Z' }
ASCII_DIGIT = _{ '0'..'9' }
ASCII_ALPHANUM = _{ ASCII_ALPHA | ASCII_DIGIT }
ASCII_HEX_DIGIT = _{ '0'..'9' | 'a'..'f' | 'A'..'F' }

// 标识符
identifier = @{ ASCII_ALPHA ~ (ASCII_ALPHANUM | "_")* }

// 顶层规则
idl_file = { SOI ~ (module_def | struct_def | enum_def | const_def | typedef_def | interface_def | union_def)* ~ EOI }

// 模块定义
module_def = { "module" ~ identifier ~ "{" ~ module_item* ~ "}" ~ ";" }
module_item = { const_def | struct_def | enum_def | typedef_def | pragma_def | interface_def | union_def | module_def }

// 常量定义
const_def = { "const" ~ const_type ~ identifier ~ "=" ~ const_value ~ ";" }

// 常量类型
const_type = { 
    "long" | "double" | "float" | "boolean" | "string" | "char" | "wchar" | "octet" |
    "long" ~ "long" | 
    "unsigned" ~ "long" ~ "long" | 
    "unsigned" ~ "long" | 
    "unsigned" ~ "short" | 
    "wstring"
}

// 常量值
const_value = {
    hex_number | number | string | boolean | char_literal | identifier
}

// 数值类型
number = @{ ("+" | "-")? ~ ASCII_DIGIT+ ~ ("." ~ ASCII_DIGIT+)? }
hex_number = @{ ("0x" | "0X") ~ ASCII_HEX_DIGIT+ }
integer = @{ ASCII_DIGIT+ }
float = @{ ASCII_DIGIT+ ~ "." ~ ASCII_DIGIT+ }

// 字符串和布尔类型
string = { "\"" ~ (!"\"" ~ ANY)* ~ "\"" }
boolean = { "true" | "false" | "TRUE" | "FALSE" }
char_literal = { "'" ~ (!"'" ~ ANY) ~ "'" }

// 结构体定义
struct_def = { annotation* ~ "struct" ~ identifier ~ "{" ~ member_def* ~ "}" ~ ";" }
member_def = { annotation* ~ type_spec ~ identifier ~ array_spec? ~ ";" }
array_spec = { "[" ~ integer ~ "]" }

// 枚举定义
enum_def = { annotation* ~ "enum" ~ identifier ~ "{" ~ enum_value_def ~ ("," ~ enum_value_def)* ~ ","? ~ "}" ~ ";" }
enum_value_def = { identifier ~ ("=" ~ integer)? }

// 类型定义
typedef_def = { "typedef" ~ type_spec ~ identifier ~ ";" }

// 类型规范
type_spec = { 
    "void" | "double" | "float" | "boolean" | "char" | "wchar" | "octet" |
    "short" | "unsigned" ~ "short" | 
    "long" ~ "long" | "unsigned" ~ "long" ~ "long" | 
    "long" | "unsigned" ~ "long" | 
    string_type | wstring_type |
    sequence_type | 
    identifier 
}

string_type = { "string" ~ ("<" ~ integer ~ ">")? }
wstring_type = { "wstring" ~ ("<" ~ integer ~ ">")? }
sequence_type = { "sequence" ~ "<" ~ type_spec ~ ("," ~ integer)? ~ ">" }

// 接口定义
interface_def = { annotation* ~ "interface" ~ identifier ~ (":" ~ identifier)? ~ "{" ~ interface_member* ~ "}" ~ ";" }
interface_member = { method_def }
method_def = { annotation* ~ type_spec ~ identifier ~ "(" ~ method_param_list? ~ ")" ~ ";" }
method_param_list = { method_param ~ ("," ~ method_param)* }
method_param = { param }
param = { (in_param | out_param | inout_param | simple_param) ~ type_spec ~ identifier }
in_param = @{ "in" ~ WHITESPACE }
out_param = @{ "out" ~ WHITESPACE }
inout_param = @{ "inout" ~ WHITESPACE }
simple_param = { "" }

// 联合类型定义
union_def = { 
    annotation* ~ "union" ~ identifier ~ "switch" ~ "(" ~ type_spec ~ ")" ~ "{" ~ union_case* ~ "}" ~ ";"
}
union_case = { 
    ("case" ~ const_value ~ ":" ~ type_spec ~ identifier ~ ";") | 
    ("default" ~ ":" ~ type_spec ~ identifier ~ ";")
}

// pragma定义
pragma_def = { "#pragma" ~ identifier ~ (identifier | string)* ~ ";"? }

// 注解
annotation = { "@" ~ identifier ~ ("(" ~ annotation_param? ~ ")")? }
annotation_param = { annotation_key_value | annotation_value }
annotation_key_value = { identifier ~ "=" ~ annotation_value }
annotation_value = { string | integer | float | boolean | identifier }
wchar_literal = { "L" ~ "'" ~ (!"'" ~ ANY)* ~ "'" }
wstring_literal = { "L" ~ "\"" ~ (!"\"" ~ ANY)* ~ "\"" }
double_value = { float }
float_value = { float ~ ("f" | "F")? }