/*
** Copyright (C) 2008-2021 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 <array>

#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <signal.h>

#include "mu-msg.hh"
#include "mu-maildir.hh"
#include "mu-query-match-deciders.hh"
#include "mu-query.hh"
#include "mu-bookmarks.hh"
#include "mu-runtime.hh"

#include "utils/mu-util.h"
#include "utils/mu-str.h"
#include "utils/mu-date.h"

#include "mu-cmd.hh"

using namespace Mu;

struct OutputInfo {
	Xapian::docid       docid{};
	bool                header{};
	bool                footer{};
	bool                last{};
	Option<QueryMatch&> match_info;
};

constexpr auto FirstOutput{OutputInfo{0, true, false}};
constexpr auto LastOutput{OutputInfo{0, false, true}};

using OutputFunc = std::function<bool(MuMsg*, const OutputInfo&, const MuConfig*, GError**)>;

static gboolean
print_internal(const Store&       store,
               const std::string& expr,
               gboolean           xapian,
               gboolean           warn,
               GError**           err)
{
	std::cout << store.parse_query(expr, xapian) << "\n";

	return TRUE;
}

/* returns MU_MSG_FIELD_ID_NONE if there is an error */
static MuMsgFieldId
sort_field_from_string(const char* fieldstr, GError** err)
{
	MuMsgFieldId mfid;

	mfid = mu_msg_field_id_from_name(fieldstr, FALSE);

	/* not found? try a shortcut */
	if (mfid == MU_MSG_FIELD_ID_NONE && strlen(fieldstr) == 1)
		mfid = mu_msg_field_id_from_shortcut(fieldstr[0], FALSE);
	if (mfid == MU_MSG_FIELD_ID_NONE)
		g_set_error(err,
		            MU_ERROR_DOMAIN,
		            MU_ERROR_IN_PARAMETERS,
		            "not a valid sort field: '%s'\n",
		            fieldstr);
	return mfid;
}

static Option<QueryResults>
run_query(const Store& store, const std::string& expr, const MuConfig* opts, GError** err)
{
	MuMsgFieldId sortid;

	sortid = MU_MSG_FIELD_ID_NONE;
	if (opts->sortfield) {
		sortid = sort_field_from_string(opts->sortfield, err);
		if (sortid == MU_MSG_FIELD_ID_NONE) /* error occurred? */
			return Nothing;
	}

	Mu::QueryFlags qflags{QueryFlags::None};
	if (opts->reverse)
		qflags |= QueryFlags::Descending;
	if (opts->skip_dups)
		qflags |= QueryFlags::SkipDuplicates;
	if (opts->include_related)
		qflags |= QueryFlags::IncludeRelated;
	if (opts->threads)
		qflags |= QueryFlags::Threading;

	return store.run_query(expr, sortid, qflags, opts->maxnum);
}

static gboolean
exec_cmd(MuMsg* msg, const OutputInfo& info, const MuConfig* opts, GError** err)
{
	gint     status;
	char *   cmdline, *escpath;
	gboolean rv;

	escpath = g_shell_quote(mu_msg_get_path(msg));
	cmdline = g_strdup_printf("%s %s", opts->exec, escpath);

	rv = g_spawn_command_line_sync(cmdline, NULL, NULL, &status, err);

	g_free(cmdline);
	g_free(escpath);

	return rv;
}

static gchar*
resolve_bookmark(const MuConfig* opts, GError** err)
{
	MuBookmarks* bm;
	char*        val;
	const gchar* bmfile;

	bmfile = mu_runtime_path(MU_RUNTIME_PATH_BOOKMARKS);
	bm     = mu_bookmarks_new(bmfile);
	if (!bm) {
		g_set_error(err,
		            MU_ERROR_DOMAIN,
		            MU_ERROR_FILE_CANNOT_OPEN,
		            "failed to open bookmarks file '%s'",
		            bmfile);
		return FALSE;
	}

	val = (gchar*)mu_bookmarks_lookup(bm, opts->bookmark);
	if (!val)
		g_set_error(err,
		            MU_ERROR_DOMAIN,
		            MU_ERROR_NO_MATCHES,
		            "bookmark '%s' not found",
		            opts->bookmark);
	else
		val = g_strdup(val);

	mu_bookmarks_destroy(bm);
	return val;
}

static Option<std::string>
get_query(const MuConfig* opts, GError** err)
{
	gchar *query, *bookmarkval;

	/* params[0] is 'find', actual search params start with [1] */
	if (!opts->bookmark && !opts->params[1]) {
		g_set_error(err, MU_ERROR_DOMAIN, MU_ERROR_IN_PARAMETERS, "error in parameters");
		return Nothing;
	}

	bookmarkval = NULL;
	if (opts->bookmark) {
		bookmarkval = resolve_bookmark(opts, err);
		if (!bookmarkval)
			return Nothing;
	}

	query = g_strjoinv(" ", &opts->params[1]);
	if (bookmarkval) {
		gchar* tmp;
		tmp = g_strdup_printf("%s %s", bookmarkval, query);
		g_free(query);
		query = tmp;
	}

	g_free(bookmarkval);

	std::string q{query};
	g_free(query);

	return q;
}

static gboolean
prepare_links(const MuConfig* opts, GError** err)
{
	/* note, mu_maildir_mkdir simply ignores whatever part of the
	 * mail dir already exists */

	if (!mu_maildir_mkdir(opts->linksdir, 0700, TRUE, err)) {
		mu_util_g_set_error(err,
		                    MU_ERROR_FILE_CANNOT_MKDIR,
		                    "error creating %s",
		                    opts->linksdir);
		return FALSE;
	}

	if (opts->clearlinks && !mu_maildir_clear_links(opts->linksdir, err)) {
		mu_util_g_set_error(err,
		                    MU_ERROR_FILE,
		                    "error clearing links under %s",
		                    opts->linksdir);
		return FALSE;
	}

	return TRUE;
}

static bool
output_link(MuMsg* msg, const OutputInfo& info, const MuConfig* opts, GError** err)
{
	if (info.header)
		return prepare_links(opts, err);
	else if (info.footer)
		return true;

	return mu_maildir_link(mu_msg_get_path(msg), opts->linksdir, err);
}

static void
ansi_color_maybe(MuMsgFieldId mfid, gboolean color)
{
	const char* ansi;

	if (!color)
		return; /* nothing to do */

	switch (mfid) {
	case MU_MSG_FIELD_ID_FROM: ansi = MU_COLOR_CYAN; break;

	case MU_MSG_FIELD_ID_TO:
	case MU_MSG_FIELD_ID_CC:
	case MU_MSG_FIELD_ID_BCC: ansi = MU_COLOR_BLUE; break;

	case MU_MSG_FIELD_ID_SUBJECT: ansi = MU_COLOR_GREEN; break;

	case MU_MSG_FIELD_ID_DATE: ansi = MU_COLOR_MAGENTA; break;

	default:
		if (mu_msg_field_type(mfid) == MU_MSG_FIELD_TYPE_STRING)
			ansi = MU_COLOR_YELLOW;
		else
			ansi = MU_COLOR_RED;
	}

	fputs(ansi, stdout);
}

static void
ansi_reset_maybe(MuMsgFieldId mfid, gboolean color)
{
	if (!color)
		return; /* nothing to do */

	fputs(MU_COLOR_DEFAULT, stdout);
}

static const char*
field_string_list(MuMsg* msg, MuMsgFieldId mfid)
{
	char*         str;
	const GSList* lst;
	static char   buf[80];

	lst = mu_msg_get_field_string_list(msg, mfid);
	if (!lst)
		return NULL;

	str = mu_str_from_list(lst, ',');
	if (str) {
		strncpy(buf, str, sizeof(buf) - 1);
		buf[sizeof(buf) - 1] = '\0';
		g_free(str);
		return buf;
	}

	return NULL;
}

static const char*
display_field(MuMsg* msg, MuMsgFieldId mfid)
{
	gint64 val;

	switch (mu_msg_field_type(mfid)) {
	case MU_MSG_FIELD_TYPE_STRING: {
		const gchar* str;
		str = mu_msg_get_field_string(msg, mfid);
		return str ? str : "";
	}
	case MU_MSG_FIELD_TYPE_INT:

		if (mfid == MU_MSG_FIELD_ID_PRIO) {
			const auto val  = static_cast<char>(mu_msg_get_field_numeric(msg, mfid));
			const auto prio = message_priority_from_char(val);
			return message_priority_name_c_str(prio);
		} else if (mfid == MU_MSG_FIELD_ID_FLAGS) {
			val = mu_msg_get_field_numeric(msg, mfid);
			return mu_str_flags_s((MuFlags)val);
		} else /* as string */
			return mu_msg_get_field_string(msg, mfid);

	case MU_MSG_FIELD_TYPE_TIME_T:
		val = mu_msg_get_field_numeric(msg, mfid);
		return mu_date_str_s("%c", (time_t)val);

	case MU_MSG_FIELD_TYPE_BYTESIZE:
		val = mu_msg_get_field_numeric(msg, mfid);
		return mu_str_size_s((unsigned)val);
	case MU_MSG_FIELD_TYPE_STRING_LIST: {
		const char* str;
		str = field_string_list(msg, mfid);
		return str ? str : "";
	}
	default: g_return_val_if_reached(NULL);
	}
}

static void
print_summary(MuMsg* msg, const MuConfig* opts)
{
	const char*  body;
	char*        summ;
	MuMsgOptions msgopts;

	msgopts = mu_config_get_msg_options(opts);
	body    = mu_msg_get_body_text(msg, msgopts);

	if (body)
		summ = mu_str_summarize(body, (unsigned)opts->summary_len);
	else
		summ = NULL;

	g_print("Summary: ");
	mu_util_fputs_encoded(summ ? summ : "<none>", stdout);
	g_print("\n");

	g_free(summ);
}

static void
thread_indent(const QueryMatch& info, const MuConfig* opts)
{
	const auto is_root{any_of(info.flags & QueryMatch::Flags::Root)};
	const auto first_child{any_of(info.flags & QueryMatch::Flags::First)};
	const auto last_child{any_of(info.flags & QueryMatch::Flags::Last)};
	const auto empty_parent{any_of(info.flags & QueryMatch::Flags::Orphan)};
	const auto is_dup{any_of(info.flags & QueryMatch::Flags::Duplicate)};
	// const auto is_related{any_of(info.flags & QueryMatch::Flags::Related)};

	/* indent */
	if (opts->debug) {
		::fputs(info.thread_path.c_str(), stdout);
		::fputs(" ", stdout);
	} else
		for (auto i = info.thread_level; i > 1; --i)
			::fputs("  ", stdout);

	if (!is_root) {
		if (first_child)
			::fputs("\\", stdout);
		else if (last_child)
			::fputs("/", stdout);
		else
			::fputs(" ", stdout);
		::fputs(empty_parent ? "*> " : is_dup ? "=> "
		                                      : "-> ",
		        stdout);
	}
}

static void
output_plain_fields(MuMsg* msg, const char* fields, gboolean color, gboolean threads)
{
	const char* myfields;
	int         nonempty;

	g_return_if_fail(fields);

	for (myfields = fields, nonempty = 0; *myfields; ++myfields) {
		MuMsgFieldId mfid;
		mfid = mu_msg_field_id_from_shortcut(*myfields, FALSE);

		if (mfid == MU_MSG_FIELD_ID_NONE ||
		    (!mu_msg_field_xapian_value(mfid) && !mu_msg_field_xapian_contact(mfid)))
			nonempty += printf("%c", *myfields);

		else {
			ansi_color_maybe(mfid, color);
			nonempty += mu_util_fputs_encoded(display_field(msg, mfid), stdout);
			ansi_reset_maybe(mfid, color);
		}
	}

	if (nonempty)
		fputs("\n", stdout);
}

static gboolean
output_plain(MuMsg* msg, const OutputInfo& info, const MuConfig* opts, GError** err)
{
	if (!msg)
		return true;

	/* we reuse the color (whatever that may be)
	 * for message-priority for threads, too */
	ansi_color_maybe(MU_MSG_FIELD_ID_PRIO, !opts->nocolor);
	if (opts->threads && info.match_info)
		thread_indent(*info.match_info, opts);

	output_plain_fields(msg, opts->fields, !opts->nocolor, opts->threads);

	if (opts->summary_len > 0)
		print_summary(msg, opts);

	return TRUE;
}

G_GNUC_UNUSED static std::string
to_string(const Mu::Sexp& sexp, bool color, size_t level = 0)
{
	Mu::MaybeAnsi col{color};
	using Color = Mu::MaybeAnsi::Color;

	// clang/libc++ don't allow constexpr here
	const std::array<Color, 6> rainbow = {
	    Color::BrightBlue,
	    Color::Green,
	    Color::Yellow,
	    Color::Magenta,
	    Color::Cyan,
	    Color::BrightGreen,
	};

	std::stringstream sstrm;

	switch (sexp.type()) {
	case Sexp::Type::List: {
		const auto bracecol{col.fg(rainbow[level % rainbow.size()])};
		sstrm << bracecol << "(";

		bool first{true};
		for (auto&& child : sexp.list()) {
			sstrm << (first ? "" : " ") << to_string(child, color, level + 1);
			first = false;
		}
		sstrm << bracecol << ")";
		break;
	}
	case Sexp::Type::String:
		sstrm << col.fg(Color::BrightCyan) << Mu::quote(sexp.value()) << col.reset();
		break;
	case Sexp::Type::Number:
		sstrm << col.fg(Color::BrightMagenta) << sexp.value() << col.reset();
		break;
	case Sexp::Type::Symbol:
		sstrm << (col.fg(sexp.value().at(0) == ':' ? Color::BrightGreen
		                                           : Color::BrightBlue))
		      << sexp.value() << col.reset();
		break;
	default: throw std::logic_error("invalid type");
	}

	return sstrm.str();
}

static bool
output_sexp(MuMsg* msg, const OutputInfo& info, const MuConfig* opts, GError** err)
{
	if (!msg)
		return true;

	fputs(msg_to_sexp(msg, 0, MU_MSG_OPTION_HEADERS_ONLY).to_sexp_string().c_str(), stdout);
	fputs("\n", stdout);

	return true;
}

static bool
output_json(MuMsg* msg, const OutputInfo& info, const MuConfig* opts, GError** err)
{
	if (info.header) {
		g_print("[\n");
		return true;
	}

	if (info.footer) {
		g_print("]\n");
		return true;
	}

	g_print("%s%s\n",
	        msg_to_sexp(msg, info.docid, MU_MSG_OPTION_HEADERS_ONLY).to_json_string().c_str(),
	        info.last ? "" : ",");

	return true;
}

static void
print_attr_xml(const char* elm, const char* str)
{
	gchar* esc;

	if (mu_str_is_empty(str))
		return; /* empty: don't include */

	esc = g_markup_escape_text(str, -1);
	g_print("\t\t<%s>%s</%s>\n", elm, esc, elm);
	g_free(esc);
}

static bool
output_xml(MuMsg* msg, const OutputInfo& info, const MuConfig* opts, GError** err)
{
	if (info.header) {
		g_print("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n");
		g_print("<messages>\n");
		return true;
	}

	if (info.footer) {
		g_print("</messages>\n");
		return true;
	}

	g_print("\t<message>\n");
	print_attr_xml("from", mu_msg_get_from(msg));
	print_attr_xml("to", mu_msg_get_to(msg));
	print_attr_xml("cc", mu_msg_get_cc(msg));
	print_attr_xml("subject", mu_msg_get_subject(msg));
	g_print("\t\t<date>%u</date>\n", (unsigned)mu_msg_get_date(msg));
	g_print("\t\t<size>%u</size>\n", (unsigned)mu_msg_get_size(msg));
	print_attr_xml("msgid", mu_msg_get_msgid(msg));
	print_attr_xml("path", mu_msg_get_path(msg));
	print_attr_xml("maildir", mu_msg_get_maildir(msg));
	g_print("\t</message>\n");

	return true;
}

static OutputFunc
get_output_func(const MuConfig* opts, GError** err)
{
	switch (opts->format) {
	case MU_CONFIG_FORMAT_LINKS: return output_link;
	case MU_CONFIG_FORMAT_EXEC: return exec_cmd;
	case MU_CONFIG_FORMAT_PLAIN: return output_plain;
	case MU_CONFIG_FORMAT_XML: return output_xml;
	case MU_CONFIG_FORMAT_SEXP: return output_sexp;
	case MU_CONFIG_FORMAT_JSON: return output_json;

	default: g_return_val_if_reached(NULL); return NULL;
	}
}

static bool
output_query_results(const QueryResults& qres, const MuConfig* opts, GError** err)
{
	const auto output_func{get_output_func(opts, err)};
	if (!output_func)
		return false;

	gboolean rv{true};
	output_func(NULL, FirstOutput, opts, NULL);

	size_t n{0};
	for (auto&& item : qres) {
		n++;
		auto msg{item.floating_msg()};
		if (!msg)
			continue;

		if (opts->after != 0 && mu_msg_get_timestamp(msg) < opts->after)
			continue;

		rv = output_func(msg,
		                 {item.doc_id(),
		                  false,
		                  false,
		                  n == qres.size(), /* last? */
		                  item.query_match()},
		                 opts,
		                 err);
		if (!rv)
			break;
	}
	output_func(NULL, LastOutput, opts, NULL);

	return rv;
}

static gboolean
process_query(const Store& store, const std::string& expr, const MuConfig* opts, GError** err)
{
	auto qres{run_query(store, expr, opts, err)};
	if (!qres)
		return FALSE;

	if (qres->empty()) {
		mu_util_g_set_error(err, MU_ERROR_NO_MATCHES, "no matches for search expression");
		return false;
	}

	return output_query_results(*qres, opts, err);
}

static gboolean
execute_find(const Store& store, const MuConfig* opts, GError** err)
{
	auto expr{get_query(opts, err)};
	if (!expr)
		return FALSE;

	if (opts->format == MU_CONFIG_FORMAT_XQUERY)
		return print_internal(store, *expr, TRUE, FALSE, err);
	else if (opts->format == MU_CONFIG_FORMAT_MQUERY)
		return print_internal(store, *expr, FALSE, opts->verbose, err);
	else
		return process_query(store, *expr, opts, err);
}

static gboolean
format_params_valid(const MuConfig* opts, GError** err)
{
	switch (opts->format) {
	case MU_CONFIG_FORMAT_EXEC: break;
	case MU_CONFIG_FORMAT_PLAIN:
	case MU_CONFIG_FORMAT_SEXP:
	case MU_CONFIG_FORMAT_JSON:
	case MU_CONFIG_FORMAT_LINKS:
	case MU_CONFIG_FORMAT_XML:
	case MU_CONFIG_FORMAT_XQUERY:
	case MU_CONFIG_FORMAT_MQUERY:
		if (opts->exec) {
			mu_util_g_set_error(err,
			                    MU_ERROR_IN_PARAMETERS,
			                    "--exec and --format cannot be combined");
			return FALSE;
		}
		break;
	default:
		mu_util_g_set_error(err,
		                    MU_ERROR_IN_PARAMETERS,
		                    "invalid output format %s",
		                    opts->formatstr ? opts->formatstr : "<none>");
		return FALSE;
	}

	if (opts->format == MU_CONFIG_FORMAT_LINKS && !opts->linksdir) {
		mu_util_g_set_error(err, MU_ERROR_IN_PARAMETERS, "missing --linksdir argument");
		return FALSE;
	}

	if (opts->linksdir && opts->format != MU_CONFIG_FORMAT_LINKS) {
		mu_util_g_set_error(err,
		                    MU_ERROR_IN_PARAMETERS,
		                    "--linksdir is only valid with --format=links");
		return FALSE;
	}

	return TRUE;
}

static gboolean
query_params_valid(const MuConfig* opts, GError** err)
{
	const gchar* xpath;

	if (!opts->params[1]) {
		mu_util_g_set_error(err, MU_ERROR_IN_PARAMETERS, "missing query");
		return FALSE;
	}

	xpath = mu_runtime_path(MU_RUNTIME_PATH_XAPIANDB);
	if (mu_util_check_dir(xpath, TRUE, FALSE))
		return TRUE;

	mu_util_g_set_error(err,
	                    MU_ERROR_FILE_CANNOT_READ,
	                    "'%s' is not a readable Xapian directory",
	                    xpath);
	return FALSE;
}

MuError
Mu::mu_cmd_find(const Store& store, const MuConfig* opts, GError** err)
{
	g_return_val_if_fail(opts, MU_ERROR_INTERNAL);
	g_return_val_if_fail(opts->cmd == MU_CONFIG_CMD_FIND, MU_ERROR_INTERNAL);

	MuConfig myopts{*opts};

	if (myopts.exec)
		myopts.format = MU_CONFIG_FORMAT_EXEC; /* pseudo format */

	if (!query_params_valid(&myopts, err) || !format_params_valid(&myopts, err))
		return MU_G_ERROR_CODE(err);

	if (!execute_find(store, &myopts, err))
		return MU_G_ERROR_CODE(err);
	else
		return MU_OK;
}