module Std::String {

extern func bux_strlen(s: String) -> uint;
extern func bux_strcmp(a: String, b: String) -> int;
extern func bux_strncmp(a: String, b: String, n: uint) -> int;
extern func bux_strcpy(dest: *char8, src: String) -> *char8;
extern func bux_strcat(dest: *char8, src: String) -> *char8;
extern func bux_strncpy(dest: *char8, src: String, n: uint) -> *char8;
extern func bux_strstr(haystack: String, needle: String) -> String;
extern func bux_str_contains(haystack: String, needle: String) -> int;
extern func bux_str_slice(s: String, start: uint, len: uint) -> String;
extern func bux_str_trim_left(s: String) -> String;
extern func bux_str_trim_right(s: String) -> String;
extern func bux_str_trim(s: String) -> String;
extern func bux_int_to_str(n: int64) -> String;
extern func bux_str_to_int(s: String) -> int64;
extern func bux_sb_new(initial_cap: uint) -> *void;
extern func bux_sb_append(sb: *void, s: String);
extern func bux_sb_append_int(sb: *void, n: int64);
extern func bux_sb_append_float(sb: *void, f: float64);
extern func bux_sb_append_char(sb: *void, c: char8);
extern func bux_sb_build(sb: *void) -> String;
extern func bux_sb_free(sb: *void);
extern func bux_str_split_count(s: String, delim: String) -> uint;
extern func bux_str_split_part(s: String, delim: String, index: uint) -> String;
extern func bux_str_join2(a: String, b: String, sep: String) -> String;


func String_Len(s: String) -> uint {
    return bux_strlen(s);
}

func String_Eq(a: String, b: String) -> bool {
    return bux_strcmp(a, b) == 0;
}

func String_Concat(a: String, b: String) -> String {
    let len_a: uint = bux_strlen(a);
    let len_b: uint = bux_strlen(b);
    let total: uint = len_a + len_b + 1;
    let buf: *char8 = bux_alloc(total) as *char8;
    bux_strcpy(buf, a);
    bux_strcat(buf, b);
    return buf;
}

func String_Copy(s: String) -> String {
    let len: uint = bux_strlen(s);
    let buf: *char8 = bux_alloc(len + 1) as *char8;
    bux_strcpy(buf, s);
    return buf;
}

func String_StartsWith(s: String, prefix: String) -> bool {
    let s_len: uint = bux_strlen(s);
    let p_len: uint = bux_strlen(prefix);
    if p_len > s_len {
        return false;
    }
    let r: int = bux_strncmp(s, prefix, p_len);
    return r == 0;
}

func String_EndsWith(s: String, suffix: String) -> bool {
    let s_len: uint = bux_strlen(s);
    let suf_len: uint = bux_strlen(suffix);
    if suf_len > s_len {
        return false;
    }
    let start: uint = s_len - suf_len;
    let tail: String = bux_str_slice(s, start, suf_len);
    let eq: bool = bux_strcmp(tail, suffix) == 0;
    return eq;
}

func String_Contains(s: String, substr: String) -> bool {
    let r: int = bux_str_contains(s, substr);
    return r != 0;
}

func String_Slice(s: String, start: uint, len: uint) -> String {
    return bux_str_slice(s, start, len);
}

func String_Trim(s: String) -> String {
    return bux_str_trim(s);
}

func String_TrimLeft(s: String) -> String {
    return bux_str_trim_left(s);
}

func String_TrimRight(s: String) -> String {
    return bux_str_trim_right(s);
}

func String_FromInt(n: int64) -> String {
    return bux_int_to_str(n);
}

func String_ToInt(s: String) -> int64 {
    return bux_str_to_int(s);
}

// String Builder — efficient string construction
struct StringBuilder {
    handle: *void,
}

func StringBuilder_New() -> StringBuilder {
    return StringBuilder { handle: bux_sb_new(64) };
}

func StringBuilder_NewCap(cap: uint) -> StringBuilder {
    return StringBuilder { handle: bux_sb_new(cap) };
}

func StringBuilder_Append(sb: *StringBuilder, s: String) {
    bux_sb_append(sb.handle, s);
}

func StringBuilder_AppendInt(sb: *StringBuilder, n: int64) {
    bux_sb_append_int(sb.handle, n);
}

func StringBuilder_AppendFloat(sb: *StringBuilder, f: float64) {
    bux_sb_append_float(sb.handle, f);
}

func StringBuilder_AppendChar(sb: *StringBuilder, c: char8) {
    bux_sb_append_char(sb.handle, c);
}

func StringBuilder_Build(sb: *StringBuilder) -> String {
    return bux_sb_build(sb.handle);
}

func StringBuilder_Free(sb: *StringBuilder) {
    bux_sb_free(sb.handle);
}

// ---------------------------------------------------------------------------
// String split/join
// ---------------------------------------------------------------------------

func String_SplitCount(s: String, delim: String) -> uint {
    return bux_str_split_count(s, delim);
}

func String_SplitPart(s: String, delim: String, index: uint) -> String {
    return bux_str_split_part(s, delim, index);
}

func String_Join2(a: String, b: String, sep: String) -> String {
    return bux_str_join2(a, b, sep);
}

}