#include <ctype.h>
#include <string>
#include <string_view>

#include "data.h"

extern CfgA& g_cfg;
extern FileView<ElvDataA> g_fvElv;
extern FileView<DlvDataA> g_fvDlv;

void OpenOnline(int iEp)
{
	wchar_t url[sizeof(g_cfg.url)+4];
	Swprintf(url, L"%s%d", g_cfg.url, iEp);
	INT_PTR r = reinterpret_cast<INT_PTR>(
	    ShellExecute(nullptr, L"open", url, nullptr, nullptr, SW_SHOWNORMAL));
	if (r <= 32)
		throw Win32Error();
}

void OpenWiki(int iEp)
{
	const DlvDataA& d = g_fvDlv.At(iEp-1);
	wchar_t url[sizeof(d.wiki)+35];
	Swprintf(url, L"https://www.detectiveconanworld.com%s", d.wiki);
	INT_PTR r = reinterpret_cast<INT_PTR>(
	    ShellExecute(nullptr, L"open", url, nullptr, nullptr, SW_SHOWNORMAL));
	if (r <= 32)
		throw Win32Error();
}

static inline bool MatchFileName(wchar_t (&file)[MAX_PATH], const wchar_t* const siEp) noexcept
{
	/* This is a hand-written parser that matches file names of
	 * the type "Detective Conan - 010.mkv". */

	wchar_t* f = file;

	/* Match Detective Conan prefix. */
	if (*f != L'D' && *f != L'd')
		return false;
	f++;

	if (wcsncmp(f, L"etective", 8) != 0)
		return false;
	f += 8;

	if (*f != L' ' && *f != L'_' && *f != L'-')
		return false;
	f++;

	if (*f != L'C' && *f != L'c')
		return false;
	f++;

	if (wcsncmp(f, L"onan", 4) != 0)
		return false;
	f += 4;

	/* Match garbage before episode number. */
	while (*f == L' ' || *f == L'_' || *f == L'-' || *f == L'0')
		f++;

	/* Match episode number. */
	size_t lenEp = wcslen(siEp);
	if (wcsncmp(f, siEp, lenEp) != 0)
		return false;
	f += lenEp;

	if (isdigit(*f))
		return false;

	return true;
}

static bool FindMatchingFile(wchar_t (&file)[MAX_PATH], const wchar_t* const root,
    const wchar_t* const siEp, const int level = 0)
{
	/* Don't recurse too much. */
	if (level > 3)
		return false;

	wchar_t pat[MAX_PATH];
	Swprintf(pat, L"%s\\*", root);

	WIN32_FIND_DATA fdata;
	HANDLE hf = FindFirstFile(pat, &fdata);
	if (hf == INVALID_HANDLE_VALUE)
		throw Win32Error().what();

	do {
		if (fdata.cFileName[0] == L'.')
			continue;
		if (fdata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
			/* Recurse into directory. */
			wchar_t root2[MAX_PATH];
			Swprintf(root2, L"%s\\%s", root, fdata.cFileName);
			try {
				if (FindMatchingFile(file, root2, siEp, level+1))
					return true;
			} catch (...) {
				FindClose(hf);
				throw;
			}
		}
		else	/* Try to match file name. */
			if (MatchFileName(fdata.cFileName, siEp)) {
				Swprintf(file, L"%s\\%s", root, fdata.cFileName);
				return true;
			}
	} while (FindNextFile(hf, &fdata));

	DWORD e = GetLastError();
	FindClose(hf);
	if (e != ERROR_NO_MORE_FILES)
		throw Win32Error(e);

	return false;
}

bool OpenLocally(int iEp)
{
	wchar_t file[MAX_PATH];
	if (FindMatchingFile(file, g_cfg.root, g_fvElv.At(iEp-1).siEp)) {
		INT_PTR r = reinterpret_cast<INT_PTR>(
		    ShellExecute(nullptr, L"open", file, nullptr, nullptr, SW_SHOWNORMAL));
		if (r <= 32)
			throw Win32Error();
		return true;
	} else
		return false;
}