/*++
Copyright (c) 2006 Microsoft Corporation

Module Name:

    datalog_frontend.cpp

Abstract:

    <abstract>

Author:

    Leonardo de Moura (leonardo) 2010-05-18.

Revision History:

--*/

#include<iostream>
#include<time.h>
#include<signal.h>
#include "util/stopwatch.h"
#include "smt/params/smt_params.h"
#include "ast/arith_decl_plugin.h"
#include "ast/reg_decl_plugins.h"
#include "muz/rel/dl_compiler.h"
#include "muz/transforms/dl_mk_filter_rules.h"
#include "muz/rel/dl_finite_product_relation.h"
#include "muz/base/dl_context.h"
#include "muz/rel/rel_context.h"
#include "muz/fp/dl_register_engine.h"
#include "muz/fp/datalog_parser.h"
#include "shell/datalog_frontend.h"
#include "util/timeout.h"
#include "util/mutex.h"

static stopwatch g_overall_time;
static stopwatch g_piece_timer;
static unsigned t_parsing = 0;

static datalog::context * g_ctx = nullptr;
static datalog::rule_set * g_orig_rules;
static datalog::instruction_block * g_code;
static datalog::execution_context * g_ectx;

static mutex *display_stats_mux = new mutex;


static void display_statistics(
    std::ostream& out,
    datalog::context& ctx,
    datalog::rule_set& orig_rules,
    datalog::instruction_block& code,
    datalog::execution_context& ex_ctx,
    bool verbose
    )
{
    lock_guard lock(*display_stats_mux);
    g_piece_timer.stop();
    unsigned t_other = static_cast<int>(g_piece_timer.get_seconds()*1000);
    g_overall_time.stop();

    code.process_all_costs();
    {
        params_ref p;
        p.set_bool("output_profile", true);
        p.set_uint("profile_milliseconds_threshold", 100);
        ctx.updt_params(p);

        IF_VERBOSE(2,
                   out << "--------------\n";
                   out << "original rules\n";
                   orig_rules.display(out);

                   out << "---------------\n";
                   out << "generated rules\n";
                   ctx.display_rules(out);

                   out << "--------------\n";
                   out << "instructions  \n";
                   code.display(ex_ctx, out);

                   out << "--------------\n";
                   out << "big relations \n";
                   ex_ctx.report_big_relations(1000, out););
    }
    IF_VERBOSE(2,
               out << "--------------\n";
               out << "relation sizes\n";
               ctx.get_rel_context()->get_rmanager().display_relation_sizes(out););

    if (verbose) {
        out << "--------------\n";
        out << "rules\n";
        ctx.display_rules(out);
    }

    out << "Time: " << static_cast<int>(g_overall_time.get_seconds()*1000) << "ms\n";
    out << "Parsing: " << t_parsing << "ms, other: " << t_other << "ms\n";
}


static void display_statistics() {
    if (g_ctx) {
        display_statistics(std::cout, *g_ctx, *g_orig_rules, *g_code, *g_ectx, true);
    }
}

static void on_timeout() {
    display_statistics();
    _Exit(0);
}

static void STD_CALL on_ctrl_c(int) {
    signal (SIGINT, SIG_DFL);
    display_statistics();
    raise(SIGINT);
}


unsigned read_datalog(char const * file) {
    IF_VERBOSE(1, verbose_stream() << "Z3 Datalog Engine\n";);
    smt_params     s_params;
    ast_manager m;
    reg_decl_plugins(m);
    datalog::register_engine re;
    g_overall_time.start();
    register_on_timeout_proc(on_timeout);
    signal(SIGINT, on_ctrl_c);
    params_ref params;
    params.set_sym("engine", symbol("datalog"));

    datalog::context ctx(m, re, s_params, params);
    datalog::relation_manager & rmgr = ctx.get_rel_context()->get_rmanager();
    datalog::relation_plugin & inner_plg = *rmgr.get_relation_plugin(symbol("tr_hashtable"));
    rmgr.register_plugin(alloc(datalog::finite_product_relation_plugin, inner_plg, rmgr));

    g_piece_timer.reset();
    g_piece_timer.start();

    bool wpa_benchmark = datalog::is_directory(std::string(file));
    if (wpa_benchmark) {
        scoped_ptr<datalog::wpa_parser> parser = datalog::wpa_parser::create(ctx, m);
        if (!parser->parse_directory(file)) {
            std::cerr << "ERROR: failed to parse file\n";
            return 1;
        }
    }
    else {
        scoped_ptr<datalog::parser> parser = datalog::parser::create(ctx, m);
        if (!parser->parse_file(file)) {
            std::cerr << "ERROR: failed to parse file\n";
            return 1;
        }
    }

    g_piece_timer.stop();
    t_parsing = static_cast<int>(g_piece_timer.get_seconds()*1000);
    IF_VERBOSE(1, verbose_stream() << "parsing finished\n";);
    IF_VERBOSE(1, verbose_stream() << "running saturation...\n";);
    g_piece_timer.reset();
    g_piece_timer.start();
    //all rules were added
    ctx.close();

    TRACE("dl_compiler", ctx.display(tout););

    datalog::rule_set original_rules(ctx.get_rules());

    datalog::instruction_block rules_code;
    datalog::instruction_block termination_code;
    datalog::execution_context ex_ctx(ctx);

    IF_VERBOSE(10, original_rules.display_deps(verbose_stream()););

    g_ctx = &ctx;
    g_orig_rules = &original_rules;
    g_code = &rules_code;
    g_ectx = &ex_ctx;

    try {
        g_piece_timer.reset();
        g_piece_timer.start();

        bool early_termination;
        unsigned timeout = ctx.initial_restart_timeout();
        if (timeout == 0) {
            timeout = UINT_MAX;
        }
        do {
            ctx.get_rel_context()->transform_rules();

            datalog::compiler::compile(ctx, ctx.get_rules(), rules_code, termination_code);

            TRACE("dl_compiler", rules_code.display(ex_ctx, tout););

            rules_code.make_annotations(ex_ctx);

            ex_ctx.set_timelimit(timeout);

            early_termination = !rules_code.perform(ex_ctx);
            if(early_termination) {
                IF_VERBOSE(10, ex_ctx.report_big_relations(1000, verbose_stream()););
                if (memory::above_high_watermark()) {
                    throw out_of_memory_error();
                }
            }
            ex_ctx.reset_timelimit();
            TRUSTME( termination_code.perform(ex_ctx) );
            ctx.saturation_was_run();

            if (early_termination) {
                IF_VERBOSE(1, verbose_stream() << "restarting saturation\n";);

                uint64_t new_timeout = static_cast<uint64_t>(timeout)*ctx.initial_restart_timeout();
                if(new_timeout>UINT_MAX) {
                    timeout=UINT_MAX;
                }
                else {
                    timeout=static_cast<unsigned>(new_timeout);
                }

                rules_code.process_all_costs();
                rules_code.reset();
                termination_code.reset();
                ex_ctx.reset();
                ctx.reopen();
                ctx.replace_rules(original_rules);
                ctx.close();
            }
        } while (early_termination);


        TRACE("dl_compiler", ctx.display(tout);
              rules_code.display(ex_ctx, tout););

        if (ctx.output_tuples()) {
            ctx.get_rel_context()->display_output_facts(ctx.get_rules(), std::cout);
        }
        display_statistics(
            std::cout,
            ctx,
            original_rules,
            rules_code,
            ex_ctx,
            false);

    }
    catch (const out_of_memory_error &) {
        std::cout << "\n\nOUT OF MEMORY!\n\n";
        display_statistics(
            std::cout,
            ctx,
            original_rules,
            rules_code,
            ex_ctx,
            true);
        return ERR_MEMOUT;
    }
    return 0;
}