/*
** Copyright (C) 2011-2022 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
**
** This program is free software; you can redistribute it and/or modify it under
** the terms of the GNU General Public License as published by the Free Software
** Foundation; either version 3, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful, but WITHOUT
** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
** FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
** details.
**
** You should have received a copy of the GNU General Public License along with
** this program; if not, write to the Free Software Foundation, Inc., 51
** Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
**
*/

#include "config.h"

#include <string>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>

#include "mu-cmd.hh"
#include "mu-contacts-cache.hh"

#include "utils/mu-util.h"
#include "utils/mu-utils.hh"
#include "utils/mu-error.hh"

using namespace Mu;


/**
 * macro to check whether the string is empty, ie. if it's NULL or
 * it's length is 0
 *
 * @param S a string
 *
 * @return TRUE if the string is empty, FALSE otherwise
 */
#define mu_str_is_empty(S) ((!(S)||!(*S))?TRUE:FALSE)


/**
 * guess the last name for the given name; clearly,
 * this is just a rough guess for setting an initial value.
 *
 * @param name a name
 *
 * @return the last name, as a newly allocated string (free with
 * g_free)
 */
static gchar*
guess_last_name(const char* name)
{
	const gchar* lastsp;

	if (!name)
		return g_strdup("");

	lastsp = g_strrstr(name, " ");

	return g_strdup(lastsp ? lastsp + 1 : "");
}

/**
 * guess the first name for the given name; clearly,
 * this is just a rough guess for setting an initial value.
 *
 * @param name a name
 *
 * @return the first name, as a newly allocated string (free with
 * g_free)
 */
static gchar*
guess_first_name(const char* name)
{
	const gchar* lastsp;

	if (!name)
		return g_strdup("");

	lastsp = g_strrstr(name, " ");

	if (lastsp)
		return g_strndup(name, lastsp - name);
	else
		return g_strdup(name);
}

/**
 * guess some nick name for the given name; if we can determine an
 * first name, last name, the nick will be first name + the first char
 * of the last name. otherwise, it's just the first name. clearly,
 * this is just a rough guess for setting an initial value for nicks.
 *
 * @param name a name
 *
 * @return the guessed nick, as a newly allocated string (free with g_free)
 */
static gchar*
cleanup_str(const char* str)
{
	gchar*       s;
	const gchar* cur;
	unsigned     i;

	if (mu_str_is_empty(str))
		return g_strdup("");

	s = g_new0(char, strlen(str) + 1);

	for (cur = str, i = 0; *cur; ++cur) {
		if (ispunct(*cur) || isspace(*cur))
			continue;
		else
			s[i++] = *cur;
	}

	return s;
}

static char*
uniquify_nick(const char* nick, GHashTable* nicks)
{
	guint u;

	for (u = 2; u != 1000; ++u) {
		char* cand;
		cand = g_strdup_printf("%s%u", nick, u);
		if (!g_hash_table_contains(nicks, cand))
			return cand;
	}

	return g_strdup(nick); /* if all else fails */
}

static gchar*
guess_nick(const char* name, GHashTable* nicks)
{
	gchar *fname, *lname, *nick;
	gchar  initial[7];

	fname = guess_first_name(name);
	lname = guess_last_name(name);

	/* if there's no last name, use first name as the nick */
	if (mu_str_is_empty(fname) || mu_str_is_empty(lname)) {
		g_free(lname);
		nick = fname;
		goto leave;
	}

	memset(initial, 0, sizeof(initial));
	/* couldn't we get an initial for the last name? */
	if (g_unichar_to_utf8(g_utf8_get_char(lname), initial) == 0) {
		g_free(lname);
		nick = fname;
		goto leave;
	}

	nick = g_strdup_printf("%s%s", fname, initial);
	g_free(fname);
	g_free(lname);

leave : {
	gchar* tmp;
	tmp = cleanup_str(nick);
	g_free(nick);
	nick = tmp;
}

	if (g_hash_table_contains(nicks, nick)) {
		char* tmp;
		tmp = uniquify_nick(nick, nicks);
		g_free(nick);
		nick = tmp;
	}

	g_hash_table_add(nicks, g_strdup(nick));

	return nick;
}

using Format = Options::Cfind::Format;

static void
print_header(Format format)
{
	switch (format) {
	case Format::Bbdb:
		g_print(";; -*-coding: utf-8-emacs;-*-\n"
			";;; file-version: 6\n");
		break;
	case Format::MuttAddressBook:
		g_print("Matching addresses in the mu database:\n");
		break;
	default:
		break;
	}
}

static void
each_contact_bbdb(const std::string& email, const std::string& name, time_t tstamp)
{
	char *fname, *lname;

	fname = guess_first_name(name.c_str());
	lname = guess_last_name(name.c_str());

	const auto now{time_to_string("%Y-%m-%d", time(NULL))};
	const auto timestamp{time_to_string("%Y-%m-%d", tstamp)};

	g_print("[\"%s\" \"%s\" nil nil nil nil (\"%s\") "
		"((creation-date . \"%s\") (time-stamp . \"%s\")) nil]\n",
		fname,
		lname,
		email.c_str(),
		now.c_str(),
		timestamp.c_str());

	g_free(fname);
	g_free(lname);
}

static void
each_contact_mutt_alias(const std::string& email,
			const std::string& name,
			GHashTable*        nicks)
{
	if (name.empty())
		return;

	char* nick = guess_nick(name.c_str(), nicks);
	mu_util_print_encoded("alias %s %s <%s>\n", nick, name.c_str(), email.c_str());

	g_free(nick);
}

static void
each_contact_wl(const std::string& email,
		const std::string& name,
		GHashTable*        nicks)
{
	if (name.empty())
		return;

	char* nick = guess_nick(name.c_str(), nicks);
	mu_util_print_encoded("%s \"%s\" \"%s\"\n", email.c_str(), nick, name.c_str());
	g_free(nick);
}

static void
print_plain(const std::string& email, const std::string& name, bool color)
{
	if (!name.empty()) {
		if (color)
			::fputs(MU_COLOR_MAGENTA, stdout);
		mu_util_fputs_encoded(name.c_str(), stdout);
		::fputs(" ", stdout);
	}

	if (color)
		::fputs(MU_COLOR_GREEN, stdout);

	mu_util_fputs_encoded(email.c_str(), stdout);

	if (color)
		fputs(MU_COLOR_DEFAULT, stdout);

	fputs("\n", stdout);
}

struct ECData {
	Format		format;
	gboolean	color, personal;
	time_t		after;
	GRegex*		rx;
	GHashTable*	nicks;
	size_t		maxnum;
	size_t		n;
};

static void
each_contact(const Mu::Contact& ci, ECData& ecdata)
{
	if (ecdata.personal && !ci.personal)
		return;

	if (ci.message_date < ecdata.after)
		return;

	if (ecdata.rx &&
	    !g_regex_match(ecdata.rx, ci.email.c_str(), (GRegexMatchFlags)0, NULL) &&
	    !g_regex_match(ecdata.rx,
			   ci.name.empty() ? "" : ci.name.c_str(),
			   (GRegexMatchFlags)0,
			   NULL))
		return;

	++ecdata.n;

	switch (ecdata.format) {
	case Format::MuttAlias:
		each_contact_mutt_alias(ci.email, ci.name, ecdata.nicks);
		break;
	case Format::MuttAddressBook:
		mu_util_print_encoded("%s\t%s\t\n", ci.email.c_str(), ci.name.c_str());
		break;
	case Format::Wanderlust:
		each_contact_wl(ci.email, ci.name, ecdata.nicks);
		break;
	case Format::OrgContact:
		if (!ci.name.empty())
			mu_util_print_encoded("* %s\n:PROPERTIES:\n:EMAIL: %s\n:END:\n\n",
					      ci.name.c_str(),
					      ci.email.c_str());
		break;
	case Format::Bbdb:
		each_contact_bbdb(ci.email, ci.name, ci.message_date);
		break;
	case Format::Csv:
		mu_util_print_encoded("%s,%s\n",
				      ci.name.empty() ? "" : Mu::quote(ci.name).c_str(),
				      Mu::quote(ci.email).c_str());
		break;
	case Format::Debug: {
		char datebuf[32];
		const auto mdate(static_cast<::time_t>(ci.message_date));
		::strftime(datebuf, sizeof(datebuf), "%F %T", ::gmtime(&mdate));
		g_print("%s\n\tname: %s\n\t%s\n\tpersonal: %s\n\tfreq: %zu\n"
			"\tlast-seen: %s\n",
			ci.email.c_str(),
			ci.name.empty() ? "<none>" : ci.name.c_str(),
			ci.display_name(true).c_str(),
			ci.personal ? "yes" : "no",
			ci.frequency,
			datebuf);
	}
		break;
	default:
		print_plain(ci.email, ci.name, ecdata.color);
	}
}

static Result<void>
run_cmd_cfind(const Mu::Store&		store,
	      const std::string&	pattern,
	      bool			personal,
	      time_t			after,
	      size_t			maxnum,
	      Format			format,
	      bool			color)
{
	ECData ecdata{};
	GError *err{};

	memset(&ecdata, 0, sizeof(ecdata));

	if (!pattern.empty()) {
		ecdata.rx = g_regex_new(
		    pattern.c_str(),
		    (GRegexCompileFlags)(G_REGEX_CASELESS | G_REGEX_OPTIMIZE),
		    (GRegexMatchFlags)0, &err);

		if (!ecdata.rx)
			return Err(Error::Code::Internal, &err, "invalid cfind regexp");
	}

	ecdata.personal = personal;
	ecdata.n        = 0;
	ecdata.after    = after;
	ecdata.maxnum   = maxnum;
	ecdata.format   = format;
	ecdata.color    = color;
	ecdata.nicks    = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);

	print_header(format);

	store.contacts_cache().for_each([&](const auto& ci) {
		each_contact(ci, ecdata);
		return ecdata.maxnum == 0 || ecdata.n < ecdata.maxnum;
	});
	g_hash_table_unref(ecdata.nicks);

	if (ecdata.rx)
		g_regex_unref(ecdata.rx);

	if (ecdata.n == 0)
		return Err(Error::Code::ContactNotFound, "no matching contacts found");
	else
		return Ok();
}

Result<void>
Mu::mu_cmd_cfind(const Mu::Store& store, const Mu::Options& opts)
{
	return run_cmd_cfind(store,
			     opts.cfind.rx_pattern,
			     opts.cfind.personal,
			     opts.cfind.after.value_or(0),
			     opts.cfind.maxnum.value_or(0),
			     opts.cfind.format,
			     !opts.nocolor);
}