// POSIX compatibility support for path translation.

#include <stdbool.h>
#include <stddef.h>
#include <string.h>
#include <ntlite/status.h>
#include "posix_path.h"

#define POSIX_SYSTEM_ROOT "/SystemRoot"

// Translates POSIX filesystem syntax into the native resource namespace.
const char* PosixTranslatePath(const char* in, char* out, size_t outSize) {
    if (!in || !out || outSize == 0) return out;

    if (strcmp(in, "/dev/null") == 0) return SYNTH_DEVNULL;
    if (strcmp(in, "/dev/zero") == 0) return SYNTH_DEVZERO;

    if (in[0] == '/') {
        size_t prefixLength = sizeof(POSIX_SYSTEM_ROOT) - 1u;
        size_t restLength = strlen(in);
        if (prefixLength + restLength + 1u > outSize) {
            out[0] = '\0';
            return out;
        }
        memcpy(out, POSIX_SYSTEM_ROOT, prefixLength);
        memcpy(out + prefixLength, in, restLength + 1u);
        return out;
    }

    size_t length = strlen(in);
    if (length + 1u > outSize) {
        out[0] = '\0';
        return out;
    }
    memcpy(out, in, length + 1u);
    return out;
}

// Translates a canonical native SystemRoot path back to POSIX syntax.
void NativeToPosix(const char* in, char* out, size_t outSize) {
    if (!in || !out || outSize == 0) return;

    size_t prefixLength = sizeof(POSIX_SYSTEM_ROOT) - 1u;
    const char* src = in;
    if (strncmp(src, POSIX_SYSTEM_ROOT, prefixLength) == 0 &&
        (src[prefixLength] == '\0' || src[prefixLength] == '/')) {
        src += prefixLength;
        if (*src == '\0') src = "/";
    }

    size_t length = strlen(src);
    if (length + 1u > outSize) {
        out[0] = '\0';
        return;
    }
    memcpy(out, src, length + 1u);
}

// Maps POSIX executable syntax into native resource/CWD syntax.
KSTATUS PosixProcessPath(const char* in, char* out, size_t outSize) {
    if (!in || !out || outSize == 0) return NTLSTATUS_INVALID_PARAMETER;
    const char* translated = PosixTranslatePath(in, out, outSize);
    if (translated != out || out[0] == '\0') return NTLSTATUS_INVALID_PARAMETER;
    return NTLSTATUS_SUCCESS;
}

static bool PosixViewEqualsI(SYS_STRING_VIEW view, const char* text) {
    size_t length = strlen(text);
    if (view.Length != length) return false;
    for (size_t i = 0; i < length; ++i) {
        char a = view.Data[i];
        char b = text[i];
        if (a >= 'A' && a <= 'Z') a = (char)(a - 'A' + 'a');
        if (b >= 'A' && b <= 'Z') b = (char)(b - 'A' + 'a');
        if (a != b) return false;
    }
    return true;
}

// POSIX owns the msvcrt compatibility alias; all other import names are native.
KSTATUS PosixResolveModuleName(void* context, SYS_STRING_VIEW requested, SYS_STRING_VIEW* canonicalOut) {
    (void)context;
    if (!canonicalOut || !SysSvIsValid(requested) || requested.Length == 0)
        return NTLSTATUS_INVALID_PARAMETER;
    if (PosixViewEqualsI(requested, "msvcrt.dll")) {
        *canonicalOut = SYS_SV_LITERAL("posix.dll");
        return NTLSTATUS_SUCCESS;
    }
    *canonicalOut = requested;
    return NTLSTATUS_SUCCESS;
}