#include "app/ui/discover/obb_discover_library.h"

#include <algorithm>
#include <cctype>

namespace obb::discover {

namespace {
std::vector<ContentEntry> s_entries;
std::string s_root;

uint32_t fake_crc32(const std::string &path) {
  uint32_t crc = 0;
  for (char c : path) {
    crc = (crc << 5) ^ static_cast<uint32_t>(c);
  }
  return crc;
}

MediaType guess_type(const std::string &path) {
  std::string ext;
  const auto pos = path.find_last_of('.');
  if (pos != std::string::npos) {
    ext = path.substr(pos);
    std::transform(ext.begin(), ext.end(), ext.begin(), [](unsigned char c) { return std::tolower(c); });
  }
  if (ext == ".mp3" || ext == ".wav") return MediaType::kAudio;
  if (ext == ".jpg" || ext == ".png") return MediaType::kImage;
  if (ext == ".tile" || ext == ".map") return MediaType::kMapTile;
  return MediaType::kArticle;
}

void add_stub_entry(const std::string &path, const char *desc) {
  ContentEntry ce;
  ce.path = path;
  ce.title = path.substr(path.find_last_of("/\\\\") + 1);
  ce.description = desc ? desc : "Hors-ligne";
  ce.type = guess_type(path);
  ce.bytes = 0;
  ce.checksum = fake_crc32(path);
  s_entries.push_back(std::move(ce));
}

}  // namespace

void library_init(const char *root_folder) {
  s_root = root_folder ? root_folder : "";
  s_entries.clear();

  if (!s_root.empty()) {
    add_stub_entry(s_root + "/welcome.txt", "Bienvenue (placeholder)");
    add_stub_entry(s_root + "/map.tile", "Tuile cartographique");
    add_stub_entry(s_root + "/[radio.mp](<http://radio.mp>)3", "Audio local");
  }

  std::sort(s_entries.begin(), s_entries.end(), [](const ContentEntry &a, const ContentEntry &b) {
    return a.title < b.title;
  });
}

std::vector<ContentEntry> list_recent(std::size_t limit) {
  std::vector<ContentEntry> out;
  out.reserve(std::min(limit, s_entries.size()));
  for (const auto &entry : s_entries) {
    out.push_back(entry);
    if (out.size() >= limit) break;
  }
  return out;
}

std::vector<ContentEntry> filter_by_type(MediaType type, std::size_t limit) {
  std::vector<ContentEntry> out;
  for (const auto &entry : s_entries) {
    if (entry.type != type) continue;
    out.push_back(entry);
    if (out.size() >= limit) break;
  }
  return out;
}

}  // namespace obb::discover