#include <libregexis024fa/graph_to_bytecode/core.h>

#include <assert.h>
#include <libregexis024fa/graph_to_bytecode/writing_commands.h>

#include <libregexis024fa/graph_to_bytecode/filter.h>

namespace regexis024 {
#define nonthrowing_assert(expr) if (!(expr)) {error = -1; return; }
    void compilation_core(std::vector<uint8_t>& result, FA_Container& fa, explicit_bookmarks& bookmark_manager,
                          size_t& read_ss_ns, size_t& fork_ss_ns, int& error)
    {
        bookmark_id_t node_start_bm_offset = bookmark_manager.new_range_of_bookmarks(fa.all.size());
        read_ss_ns = 0;
        fork_ss_ns = 0;
        assert(fa.start);
        std::vector<FA_Node*> todo = {fa.start};

        auto nodesBookmark = [&](FA_Node* node) -> bookmark_id_t {
            assert(node);
            return node_start_bm_offset + node->nodeId;
        };

        auto addBranching = [&](FA_Node* node) {
            todo.push_back(node);
        };

        while (!todo.empty()) {
            FA_Node* node = todo.back(); todo.pop_back();
            if (bookmark_manager.has_landed(nodesBookmark(node))) {
                continue;
            }
            while (true) {
                if (bookmark_manager.has_landed(nodesBookmark(node))) {
                    cmd_JUMP(result, bookmark_manager, nodesBookmark(node));
                    break;
                }
                bookmark_manager.land_bookmark(result, nodesBookmark(node));
                if (node->type == match) {
                    cmd_MATCH(result);
                    cmd_DIE(result);
                    break;
                } else if (node->type == one_char_read) {
                    FA_NodeOfOneCharRead* ocr = dynamic_cast<FA_NodeOfOneCharRead*>(node);
                    nonthrowing_assert(read_ss_ns < UINT32_MAX);
                    cmd_READ(result, read_ss_ns++);
                    addBranching(ocr->nxt_node);
                    bool can_spill = write_filter(result, bookmark_manager, {ocr->filter},{nodesBookmark(ocr->nxt_node)});
                    if (!can_spill)
                        break;
                    node = ocr->nxt_node;
                } else if (node->type == look_one_behind) {
                    FA_NodeOfLookOneBehind* lob = dynamic_cast<FA_NodeOfLookOneBehind*>(node);
                    addBranching(lob->nxt_node);
                    bool can_spill = write_filter(result, bookmark_manager, {lob->filter}, {nodesBookmark(lob->nxt_node)});
                    if (!can_spill)
                        break;
                    node = lob->nxt_node;
                } else if (node->type == forking) {
                    FA_NodeOfForking* fn = dynamic_cast<FA_NodeOfForking*>(node);
                    std::vector<FA_Node*>& nxt_options = fn->nxt_options;
                    if (nxt_options.empty()) {
                        cmd_DIE(result);
                        break;
                    }
                    if (nxt_options.size() >= 2) {
                        nonthrowing_assert(fork_ss_ns < UINT32_MAX);
                        sslot_id_t sslot = fork_ss_ns++;
                        for (size_t i = 0; i + 1 < nxt_options.size(); i++) {
                            cmd_FORK(result, bookmark_manager, sslot, nodesBookmark(nxt_options[i]));
                            addBranching(nxt_options[i]);
                        }
                    }
                    node = nxt_options.back();
                } else if (node->type == track_array_mov_imm) {
                    FA_NodeOfTrackArrayMovImm* tami = dynamic_cast<FA_NodeOfTrackArrayMovImm*>(node);
                    write_byte(result, tami->operation);
                    write_tai(result, tami->key);
                    write_quadword(result, tami->imm_value);
                    node = tami->nxt_node;
                } else if (node->type == track_array_mov_halfinvariant) {
                    FA_NodeOfTrackArrayMovHalfinvariant* tamh = dynamic_cast<FA_NodeOfTrackArrayMovHalfinvariant *>(node);
                    write_byte(result, tamh->operation);
                    write_tai(result, tamh->key);
                    node = tamh->nxt_node;
                } else if (node->type == det_char_crossroads) {
                    FA_NodeOfDetCharCrossroads* dcc = dynamic_cast<FA_NodeOfDetCharCrossroads*>(node);
                    nonthrowing_assert(read_ss_ns < UINT32_MAX);
                    if (dcc->matching)
                        cmd_MATCH(result);
                    cmd_READ(result, read_ss_ns++);
                    std::vector<codeset_t> codesets;
                    std::vector<bookmark_id_t> branches;
                    for (const DFA_CrossroadPath& p: dcc->crossroads) {
                        codesets.push_back(p.input);
                        branches.push_back(nodesBookmark(p.nxt_node));
                        addBranching(p.nxt_node);
                    }
                    bool can_spill = write_filter(result, bookmark_manager, codesets, branches);
                    if (!can_spill)
                        break;
                    if (dcc->crossroads.empty())
                        break;
                    node = dcc->crossroads[0].nxt_node;
                } else
                    assert(false);
            }
        }
    }
}