#include <malloc.h>
#include <string.h>

#include "log.h"
#include "lephisto.h"
#include "hook.h"

// The hook.
typedef struct Hook_ {
  int id;
  lua_State* L;
  unsigned int  parent;
  char* func;
  char* stack;
} Hook;

// The stack.
static unsigned int     hook_id     = 0; // Unique hook id.
static Hook*            hook_stack  = NULL;
static int              hook_mstack = 0;
static int              hook_nstack = 0;

int hook_run(Hook* hook) {
  lua_State* L;

  L = hook->L;

  lua_getglobal(L, hook->func);
  if(lua_pcall(L, 0, 0, 0))
    // Error has accured.
    WARN("Hook [%s] '%d' -> '%s' : %s", hook->stack,
        hook->parent, hook->func, lua_tostring(L, -1));

  return 0;
}

// Add/Remove hooks.
int hook_add(lua_State* L, unsigned int parent, char* func, char* stack) {
  Hook* new_hook;

  // If the memory must grow.
  if(hook_nstack+1 > hook_mstack) {
    hook_stack = realloc(hook_stack, (hook_mstack+5)*sizeof(Hook));
    hook_mstack += 5;
  }

  // Create the new hook.
  new_hook = &hook_stack[hook_nstack];
  new_hook->id      = ++hook_id;
  new_hook->L       = L;
  new_hook->parent  = parent;
  new_hook->func    = func;
  new_hook->stack   = stack;

  hook_nstack++;

  return new_hook->id;
}

void hook_rm(int id) {
  int l, m, h;
  l = 0;
  h = hook_nstack-1;

  while(l <= h) {
    m = (l+h)/2;
    if(hook_stack[m].id > id) h = m-1;
    else if(hook_stack[m].id < id) l = m+1;
    else break;
  }

  if(m == (hook_nstack-1)) return;

  // Move it!
  memmove(&hook_stack[m+1], &hook_stack[m+2], sizeof(Hook)*(hook_nstack-(m+2)));
  hook_nstack--;
}

void hook_rmParent(unsigned int parent) {
  int i;
  for(i = 0; i < hook_nstack; i++)
    if(parent == hook_stack[i].parent) {
      hook_rm(hook_stack[i].id);
      i--;
    }
}

// Run all hooks off the stack.
int hooks_run(char* stack) {
  int i;
  for(i = 0; i < hook_nstack; i++)
    if(strcmp(stack, hook_stack[i].stack)==0)
      hook_run(&hook_stack[i]);

  return 0;
}

// Clean upi after ourselves.
void hook_cleanup(void) {
  free(hook_stack);
  hook_stack  = NULL;
  // Sane defaults just in case.
  hook_nstack = 0;
  hook_mstack = 0;
}