/*
** Copyright (C) 2008-2020 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                is_first{};
        bool                is_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 Query& query, const std::string& expr, gboolean xapian,
                gboolean warn, GError **err)
{
        std::cout << query.parse(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 Query& q, 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 q.run(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 Mu::Query
get_query_obj (const Store& store, GError **err)
{
        const auto count{store.size()};

        if (count == (unsigned)-1)
                throw Mu::Error(Error::Code::Store, "invalid store");

        if (count == 0)
                throw Mu::Error(Error::Code::Store, "store is empty");

        return Mu::Query{store};
}

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.is_first && !prepare_links (opts, err))
                return FALSE;

        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) {
                        val = mu_msg_get_field_numeric (msg, mfid);
                        return mu_msg_prio_name ((MuMsgPrio)val);
                } 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 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 */
        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);

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

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

        return TRUE;
}


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)
{
        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.is_first) {
                g_print ("[\n");
                return true;
        }

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

        g_print("%s\n", msg_to_sexp(msg, info.docid, {}, MU_MSG_OPTION_HEADERS_ONLY)
                .to_sexp_string().c_str());

        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.is_first) {
                g_print ("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n");
                g_print ("<messages>\n");
                return true;
        }

        if (info.is_last) {
                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, NULL, NULL);

        for (auto&& item: qres) {

                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, item.query_match()},
                                  opts, err);
                if (!rv)
                        break;
        }
        output_func (NULL, LastOutput, NULL, NULL);

        return rv;
}

static gboolean
process_query (const Query& q, const std::string& expr, const MuConfig *opts, GError **err)
{
        gboolean rv;

        auto qres{run_query (q, 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 q{get_query_obj (store, err)};
        auto expr{get_query (opts, err)};
        if (!expr)
                return FALSE;

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