#include "memory.h"

#include "array/sc_array.h"
#include "files.h"
#include "logger.h"
#include "types.h"

static inline int ptr_in_range(uptr ptr, uptr start, uptr end) {
  return ptr >= start && ptr <= end;
}

HiloadResult memory_find_pointer(uptr ptr,
                                 struct sc_array_memreg *const regions,
                                 size_t *index) {
  for (size_t i = 0; i < sc_array_size(regions); i++) {
    uptr start = regions->elems[i].region_start;
    uptr end = regions->elems[i].region_end;
    if (ptr_in_range(ptr, start, end)) {
      if (index)
        *index = i;
      sc_log_debug("Pointer match (%p) found in index: %u, range: %p - %p\n", ptr, i, start, end);
      return HILOAD_OK;
    }
  }

  return HILOAD_FAIL;
}

HiloadResult read_memory_maps_self(struct sc_array_memreg *regions) {
  str memory_str = str_null;

  sc_array_clear(regions);
  sc_array_init(regions);

  HiloadResult res = read_stream_to_str(&memory_str, "/proc/self/maps");
  if (res == HILOAD_FAIL)
    return HILOAD_FAIL;

  char *strptr = (char *)str_ptr(memory_str);
  char *line = strtok(strptr, "\n");
  while (line) {
    MemoryRegion reg = {0};

    char perm_str[5];
    u32 dev_major;
    u32 dev_minor;
    char pathname[256];

    // clang-format off
    // Example from `cat /proc/self/maps`
    // 7fa0b66ca000-7fa0b66cc000 rw-p 00033000 fe:02 28063911 /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2
    int result = sscanf(line, "%lx-%lx %4s %lx %x:%x %lu %255s",
                        &reg.region_start,
                        &reg.region_end,
                        perm_str,
                        &reg.offset,
                        &dev_major,
                        &dev_minor,
                        &reg.inode,
                        pathname);

    if (perm_str[0] == 'r') reg.permission |= HI_MEMORY_READ;
    if (perm_str[1] == 'w') reg.permission |= HI_MEMORY_WRITE;
    if (perm_str[2] == 'x') reg.permission |= HI_MEMORY_EXECUTE;
    if (perm_str[3] == 'p') reg.permission |= HI_MEMORY_PRIVATE;
    if (perm_str[3] == 's') reg.permission |= HI_MEMORY_SHARED;
    // clang-format on

    // pathname could be empty, so we check for it
    if (result >= 8) {
      reg.pathname = strdup(pathname);
    }

    sc_array_add(regions, reg);
    line = strtok(NULL, "\n");
  }

  str_free(memory_str);

  return HILOAD_OK;
}