#ifndef LR_TABLE_H
#define LR_TABLE_H

class PgfPrinter;

class PGF_INTERNAL_DECL PgfAbstractParser
{
    typedef size_t hash_t;

protected:
    ref<PgfConcr> concr;

    struct CCat;
    struct Cont;
    struct Item;
    struct State;
    struct ExprState;

    struct Production {
        ref<PgfConcrRule> rule;

        struct {
            size_t &operator[](int i) const {
                Production *prod = containerof(Production,vars,this);
                return ((size_t*) (((CCat**) (prod+1))+prod->args.size()))[i];
            }
            size_t size() const {
                Production *prod = containerof(Production,vars,this);
                return prod->rule->ranges.size();
            }
        } vars;

        struct {
            CCat *&operator[](int i) const {
                Production *prod = containerof(Production,args,this);
                return ((CCat**) (prod+1))[i];
            }
            size_t size() const {
                Production *prod = containerof(Production,args,this);
                return (prod->rule->args != 0) ? prod->rule->args.size() : 0;
            }
        } args;

        void *operator new(size_t sz, Item *item)
        {
            size_t sz2 = item->args.size()*sizeof(CCat*)
                       + item->vars.size()*sizeof(size_t);
            Production *prod = (Production *) malloc(sz+sz2);
            memcpy(prod+1, item+1, sz2);
            return prod;
        }

        void *operator new(size_t sz, ref<PgfItem> pitem)
        {
            size_t sz2 = pitem->args.size()*sizeof(CCat*)
                       + pitem->vars.size()*sizeof(size_t);
            Production *prod = (Production *) malloc(sz+sz2);
            memset(prod+1,0,sz2);
            return prod;
        }

        void operator delete(void *p)
        {
            free(p);
        }

        Production() {
        }
    };

    struct ExprProb {
        PgfExpr expr;
        prob_t prob;
        hash_t hash;
        
        ExprProb(PgfExpr expr, prob_t prob, hash_t hash) {
            this->expr = expr;
            this->prob = prob;
            this->hash = hash;
        }
    };

    struct CCat {
        PgfMetaId fid;
        ref<PgfCCat> epsilon;
        Cont *cont;
        State *state;
        interval_t value;
        interval_t lin_idx;
        prob_t viterbi_prob;
        bool covered;
        std::vector<Production*> prods;
        std::vector<ExprState*> pending;
        std::vector<ExprProb> exprs;

        ~CCat();
    };

    struct State {
        PgfTextSpot start, end;
        bool needs_bind;
        bool did_bu_predict;
        std::map<ref<PgfConcrLincat>,Cont*> conts1;
        std::map<CCat*,Cont*> conts2;
        std::map<Cont*,interval_map<interval_map<CCat*>>> completed;
        std::vector<Item*> queue;
        prob_t viterbi_prob;

        State *next;

        bool has_items() {
            return queue.size() > 0;
        }

        void push_item(Item *item) {
            queue.push_back(item);
            std::push_heap(queue.begin(), queue.end(), item_prob_comp);
        }

        Item *pop_item() {
            Item *item = queue.front();
            std::pop_heap(queue.begin(), queue.end(), item_prob_comp);
            queue.pop_back();
            return item;
        }
    };

    static struct ItemProbComparator : std::less<Item*> {
        bool operator()(Item *item1, Item *item2) {
            return item1->inside_prob+item1->outside_prob > item2->inside_prob+item2->outside_prob;
        }
    } item_prob_comp;

    struct ItemComparator : std::less<Item*> {
        bool operator()(Item *item1, Item *item2) const;
    };

    struct Cont {
        CCat *ccat;
        ref<PgfConcrLincat> lincat;
        State *state;
        interval_map<interval_map<std::vector<Item*>>> suspended;
        std::set<Item*,ItemComparator> predicted;

        ~Cont();
    };

    struct Item {
        Cont *cont;
        uint16_t pre_alt;
        uint16_t pre_dot;
        uint16_t dot;
        vector<PgfSymbol> syms;
        ref<PgfConcrRule> rule;
        prob_t inside_prob;
        prob_t outside_prob;

        struct {
            size_t &operator[](int i) const {
                Item *item = containerof(Item,vars,this);
                return ((size_t*) (((CCat**) (item+1))+item->args.size()))[i];
            }
            size_t size() const {
                Item *item = containerof(Item,vars,this);
                return item->rule->ranges.size();
            }
        } vars;

        struct {
            CCat *&operator[](int i) const {
                Item *item = containerof(Item,args,this);
                return ((CCat**) (item+1))[i];
            }
            size_t size() const {
                Item *item = containerof(Item,args,this);
                return (item->rule->args != 0) ? item->rule->args.size() : 0;
            }
        } args;

        void *operator new(size_t sz, ref<PgfConcrRule> rule)
        {
            size_t sz2 = rule->args.size()*sizeof(CCat*)
                       + rule->ranges.size()*sizeof(size_t);
            Item *new_item = (Item *) malloc(sz+sz2);
            memset(new_item+1, 0, sz2);
            return new_item;
        }

        void *operator new(size_t sz, Item *item)
        {
            size_t sz2 = item->args.size()*sizeof(CCat*)
                       + item->vars.size()*sizeof(size_t);
            Item *new_item = (Item *) malloc(sz+sz2);
            memcpy(new_item, item, sz+sz2);
            return new_item;
        }

        void operator delete(void *p)
        {
            free(p);
        }
        
        Item() {
        }
    };

    struct ExprState {
        PgfExpr expr;
        prob_t prob;
        hash_t hash;

        CCat *res;

        size_t index;
        size_t n_args;
        CCat *args[];

        void *operator new(size_t sz, size_t n_args)
        {
            ExprState *estate = (ExprState *)
                malloc(sz+n_args*sizeof(CCat*));
            return estate;
        }
        
        void operator delete(void *p)
        {
            free(p);
        }

        ExprState() {
        }
    };

    State *current_state;
    std::map<PgfMetaId,CCat*> epsilons;
    PgfMetaId initial_fid, last_fid;

    void process(Item *item, State *state);
    void symbol(Item *item, State *state, PgfSymbol sym);
    void complete(Item *item, State *state);

    virtual State *new_state(const PgfTextSpot &start, prob_t viterbi_prob)=0;
    virtual void symbol_token(Item *item, State *state, ref<PgfSymbolKS> symks)=0;
    virtual void symbol_bind(Item *item, State *state, PgfSymbol sym)=0;
    virtual void suspend(Cont *cont, Item *item, bool do_predict, ref<PgfSymbolCat> symcat,interval_t value_i,interval_t lin_idx_i)=0;
    virtual void final_item(State *state,CCat *ccat,Item *item,interval_t value,interval_t lin_idx)=0;
    virtual void bu_predict(State *state, prob_t outside_prob, CCat *ccat)=0;

    void td_epsilon(State *state, Cont *cont, ref<PgfItem> pitem, Item *xitem, ref<PgfSymbolCat> symcat);
    void td_predict(State *state, Cont *cont, Production *prod, Item *xitem, ref<PgfSymbolCat> symcat);
    void combine(State *state, Item *item, CCat *ccat);

    static
    bool instantiate(ref<PgfConcrRule> rule1, size_t *values1, ref<PgfLParam> lparam1,
                     ref<PgfConcrRule> rule2, size_t *values2, ref<PgfLParam> lparam2);

    static
    interval_t interval(ref<PgfConcrRule> rule, size_t *values, ref<PgfLParam> lparam);

    bool get_info(CCat *ccat, ref<PgfConcrRule> *rule, size_t **pvalues);
    CCat *get_epsilon_ccat(PgfText *name, PgfMetaId fid);

    static
    void print_item(Item *item, State *state);

    static
    void print_prod(CCat *ccat, Production *prod);

public:
    PgfAbstractParser(ref<PgfConcr> concr);
    virtual ~PgfAbstractParser();
};

class PGF_INTERNAL_DECL PgfParser : private PgfAbstractParser, public PgfExprEnum, public PgfParseChart
{
    PgfMarshaller *m;
    PgfUnmarshaller *u;
    PgfText *sentence;
    bool case_sensitive;

    // The following are used only during chart updates.
    State *prev_state;
    size_t update_old_pos, update_new_pos;
    ssize_t delta_byte_pos;
    ssize_t allocated_size;

    virtual State *new_state(const PgfTextSpot &start, prob_t viterbi_prob);
    virtual void symbol_token(Item *item, State *state, ref<PgfSymbolKS> symks);
    virtual void symbol_bind(Item *item, State *state, PgfSymbol sym);
    virtual void suspend(Cont *cont,Item *item,bool do_predict,ref<PgfSymbolCat> symcat,interval_t value_i,interval_t lin_idx_i);
    virtual void final_item(State *state,CCat *ccat,Item *item,interval_t value,interval_t lin_idx);
    virtual void bu_predict(State *state, prob_t outside_prob, CCat *ccat);

    void bu_predict(PgfPhrasetable<PgfSymbolBIND> phrasetable, State *state, prob_t outside_prob);
    void bu_literal(State *state, const char *name, PgfExprParser *eparser, prob_t viterbi_prob);
    void bu_predict(PgfPhrasetable<PgfSymbolKS> phrasetable, State *state, prob_t outside_prob, ptrdiff_t min, ptrdiff_t max);
    void make_chunks(State *state, std::vector<CCat*> &chunks, prob_t prob);
    PgfExpr process_expr(ExprState *estate, prob_t *prob);

    bool td_reachable(State *state, ref<PgfItem> pitem, std::map<ref<PgfConcrLincat>, bool> &visited);
    Item *bu_item(State *state, prob_t outside_prob, ref<PgfItem> pitem);

    static
    void print_expr_state_left(PgfPrinter *printer, PgfMarshaller *m, ExprState *estate);
    static
    void print_expr_state_right(PgfPrinter *printer, ExprState *estate);
    static
    void print_expr_state(PgfMarshaller *m, ExprState *estate);

    static struct ExprStateComparator : std::less<ExprState*> {
        bool operator()(ExprState *estate1, ExprState *estate2) {
            return estate1->prob > estate2->prob;
        }
    } estate_comp;

    std::vector<ExprState*> queue;

public:
    PgfParser(ref<PgfConcr> concr, PgfText *sentence, bool case_sensitive, PgfMarshaller *m, PgfUnmarshaller *u);
    virtual ~PgfParser();

    void prepare(ref<PgfConcrLincat> start);
    void perform_search();

    virtual PgfExpr fetch(PgfDB *db, prob_t *prob);

    virtual PgfText *get_text();
    virtual void start();
    virtual bool skip(size_t i);
    virtual bool change(size_t i, PgfText *change);
    virtual void done();
};

class PGF_INTERNAL_DECL PgfParseTableMaker : private PgfAbstractParser
{
private:
    virtual State *new_state(const PgfTextSpot &start, prob_t viterbi_prob);
    virtual void symbol_token(Item *item, State *state, ref<PgfSymbolKS> symks);
    virtual void symbol_bind(Item *item, State *state, PgfSymbol sym);
    virtual void suspend(Cont *cont, Item *item, bool do_predict, ref<PgfSymbolCat> symcat,interval_t value_i,interval_t lin_idx_i);
    virtual void final_item(State *state, CCat *ccat,Item *item,interval_t value,interval_t lin_idx);
    virtual void bu_predict(State *state, prob_t outside_prob, CCat *ccat);

    static
    ref<PgfItem> clone_item(Item *item);

public:
    PgfParseTableMaker(ref<PgfConcr> concr);
    void insert_rule(ref<PgfConcrRule> rule);
    void prepare();
    PgfMetaId get_last_fid() { return last_fid; };
};

#endif