/* -------------------------------------------

  Copyright (C) 2024, Amlal El Mahrouss, licensed under Apache 2.0.

------------------------------------------- */

/**
 * @file neboot-pci-tree.c
 * @author Amlal El Mahrouss (amlal@nekernel.org)
 * @brief PCI tree implementation.
 * @version 0.1
 * @date 2024-01-22
 *
 * @copyright Copyright (c) 2024 Amlal El Mahrouss
 *
 */

#include <lib/pci-tree.h>
#include <lib/string.h>

/// BUGS: 0

/// Standard Root table (Mahrouss Table)
#define NB_PCI_ROOT_NAME "/pci-tree/@/"

static struct hw_nb_pci_tree* cb_base_tree   = nil;
static struct hw_nb_pci_tree* cb_latest_tree = nil;
static struct hw_nb_pci_tree* cb_last_tree   = nil;

/// \brief Init the PCI device tree structure.
/// \return if it already exists -> false
/// Otherwise true.
boolean cb_pci_init_tree(void) {
  cb_base_tree = (struct hw_nb_pci_tree*) (NB_PCI_TREE_BASE);

  // huh? anyway let's ignore it then.
  if (cb_base_tree->d_magic != NB_PCI_DEV_MAGIC) {
    cb_base_tree->d_magic = NB_PCI_DEV_MAGIC;

    memncpy(cb_base_tree->d_name, NB_PCI_ROOT_NAME, strlen(NB_PCI_ROOT_NAME));

    cb_base_tree->d_next_sibling = 0;
    cb_base_tree->d_off_props    = 0;
    cb_base_tree->d_sz_struct    = 0;
    cb_base_tree->d_sz_props     = 0;
    cb_base_tree->d_off_struct   = 0;
    cb_base_tree->d_version      = NB_PCI_VERSION;

    cb_base_tree->d_next_sibling = (cb_pci_num_t) (cb_base_tree + sizeof(struct hw_nb_pci_tree));
    cb_base_tree->d_first_node   = (cb_pci_num_t) cb_base_tree;

    cb_put_string(">> Append root device: " NB_PCI_ROOT_NAME "\r\n");
  }

  cb_latest_tree = cb_base_tree;

  return yes;
}

/// \brief Adds a new device to the tree.
/// \param name the device name.
/// \param struct_ptr the struct containing the device.
/// \param struct_sz the structure size.
boolean cb_pci_append_tree(const caddr_t name, cb_pci_num_t struct_ptr, cb_pci_num_t struct_sz) {
  if (!name || *name == 0 || cb_latest_tree == nil) return no;

  struct hw_nb_pci_tree* cb_pci_tree = (struct hw_nb_pci_tree*) (cb_latest_tree);

  while (cb_pci_tree->d_magic == NB_PCI_DEV_MAGIC) {
    if (strcmp(cb_pci_tree->d_name, name) == 0) return no;

    cb_pci_tree = (struct hw_nb_pci_tree*) (cb_pci_tree + sizeof(struct hw_nb_pci_tree));
  }

  cb_pci_tree->d_magic = NB_PCI_DEV_MAGIC;

  memncpy(cb_pci_tree->d_name, name, strlen(name));

  cb_pci_tree->d_off_struct = struct_ptr;
  cb_pci_tree->d_sz_struct  = struct_sz;
  cb_pci_tree->d_off_props  = 0;
  cb_pci_tree->d_sz_props   = 0;
  cb_pci_tree->d_version    = NB_PCI_VERSION;

  cb_pci_tree->d_next_sibling = (cb_pci_num_t) (cb_pci_tree + sizeof(struct hw_nb_pci_tree));
  cb_pci_tree->d_first_node   = (cb_pci_num_t) cb_latest_tree;

  cb_latest_tree = cb_pci_tree;
  cb_last_tree   = cb_pci_tree;

  cb_put_string(">> Append device: ");
  cb_put_string(name);
  cb_put_string("\r\n");

  return yes;
}