import vec:*
import vec_literals:*
import map:*
import set:*
import util:*
import str:*
import regex:*

// nonterminals are negative, terminals are positive
obj Grammer (Object) {
    var nonterminals: vec<vec<vec<int>>>
    var nonterminal_names: vec<str>
    var terminals: vec<regex>
    var start_symbol: int
    fun construct(): *Grammer {
        nonterminals.construct()
        nonterminal_names.construct()
        terminals.construct()
        start_symbol = 0
        return this
    }
    fun copy_construct(old: *Grammer): void {
        nonterminals.copy_construct(&old->nonterminals)
        nonterminal_names.copy_construct(&old->nonterminal_names)
        terminals.copy_construct(&old->terminals)
        start_symbol = old->start_symbol
    }
    fun destruct(): void {
        nonterminals.destruct()
        nonterminal_names.destruct()
        terminals.destruct()
    }
    fun operator=(other:ref Grammer):void {
        destruct()
        copy_construct(&other)
    }
    fun add_new_nonterminal(name: *char, rule: ref vec<int>): int {
        return add_new_nonterminal(str(name), rule)
    }
    fun add_new_nonterminal(name: ref str, rule: ref vec<int>): int {
        nonterminals.add(vec(rule))
        nonterminal_names.add(name)
        return -1*nonterminals.size
    }
    fun add_to_nonterminal(nonterminal: int, rule: ref vec<int>) {
        nonterminals[(-1*nonterminal)-1].add(rule)
    }
    fun add_terminal(c: *char): int {
        terminals.add(regex(c))
        return terminals.size
    }
    fun get_nonterminal_rules(nonterminal: int): ref vec<vec<int>> {
        return nonterminals[(-1*nonterminal)-1]
    }
    fun match_terminal(terminal: int, input: ref str, start: int): int {
        return terminals[terminal-1].long_match(input.getBackingMemory(), start, input.length())
    }
    fun is_terminal(x: int): bool {
        return x > 0
    }
    fun set_start_symbol(x: int) {
        start_symbol = x
    }
    fun to_string(it: BS): str {
        var rule_str = str()
        for (var i = 0; i < nonterminals[(-1*it.nonterminal)-1][it.rule_idx].size; i++;) {
            if i == it.idx_into_rule {
                rule_str += "*"
            }
            var erminal = nonterminals[(-1*it.nonterminal)-1][it.rule_idx][i]
            rule_str += to_string(erminal)
        }
        if it.idx_into_rule == nonterminals[(-1*it.nonterminal)-1][it.rule_idx].size {
            rule_str += "*"
        }
        return str("<") + nonterminal_names[(-1*it.nonterminal)-1] + " ::= " + rule_str + ", "  + it.left + ", " + it.pivot + ", " + it.right + ">"
    }
    fun to_string(erminal: int): str {
        if erminal < 0 {
            return nonterminal_names[(-1*erminal)-1]
        } else {
            return terminals[erminal-1].regexString
        }
    }
}
obj Pending (Object) {
    var nonterminal: int
    var rule_idx: int
    var idx_into_rule: int
    var left: int
    fun construct(): *Pending {
        return this->construct(0,0,0,0)
    }
    fun construct(nonterminal: int, rule_idx: int, idx_into_rule: int, left: int): *Pending {
        this->nonterminal = nonterminal;
        this->rule_idx = rule_idx;
        this->idx_into_rule = idx_into_rule;
        this->left = left;
        return this
    }
    fun copy_construct(old: *Pending): void {
        this->nonterminal = old->nonterminal;
        this->rule_idx = old->rule_idx;
        this->idx_into_rule = old->idx_into_rule;
        this->left = old->left;
    }
    fun destruct(): void { }
    fun operator=(other:ref Pending):void {
        destruct()
        copy_construct(&other)
    }
    fun operator==(rhs: ref Pending): bool {
        return nonterminal == rhs.nonterminal && rule_idx == rhs.rule_idx && idx_into_rule == rhs.idx_into_rule && left == rhs.left
    }
}
fun pending(nonterminal: int, rule_idx: int, idx_into_rule: int, left: int): Pending {
    var to_ret.construct(nonterminal, rule_idx, idx_into_rule, left): Pending
    return to_ret
}
obj Descriptor (Object) {
    var nonterminal: int
    var rule_idx: int
    var idx_into_rule: int
    var left: int
    var pivot: int
    fun construct(): *Descriptor {
        return this->construct(0,0,0,0,0)
    }
    fun construct(nonterminal: int, rule_idx: int, idx_into_rule: int, left: int, pivot: int): *Descriptor {
        this->nonterminal = nonterminal;
        this->rule_idx = rule_idx;
        this->idx_into_rule = idx_into_rule;
        this->left = left;
        this->pivot = pivot;
        return this
    }
    fun copy_construct(old: *Descriptor): void {
        this->nonterminal = old->nonterminal;
        this->rule_idx = old->rule_idx;
        this->idx_into_rule = old->idx_into_rule;
        this->left = old->left;
        this->pivot = old->pivot;
    }
    fun destruct(): void { }
    fun operator=(other:ref Descriptor):void {
        destruct()
        copy_construct(&other)
    }
    fun operator==(rhs: ref Descriptor): bool {
        return nonterminal == rhs.nonterminal && rule_idx == rhs.rule_idx && idx_into_rule == rhs.idx_into_rule && left == rhs.left && pivot == rhs.pivot
    }
}
fun descriptor(nonterminal: int, rule_idx: int, idx_into_rule: int, left: int, pivot: int): Descriptor {
    var to_ret.construct(nonterminal, rule_idx, idx_into_rule, left, pivot): Descriptor
    return to_ret
}
obj BS (Object) {
    var nonterminal: int
    var rule_idx: int
    var idx_into_rule: int
    var left: int
    var pivot: int
    var right: int
    fun construct(): *BS {
        return this->construct(0,0,0,0,0,0)
    }
    fun construct(nonterminal: int, rule_idx: int, idx_into_rule: int, left: int, pivot: int, right: int): *BS {
        this->nonterminal = nonterminal;
        this->rule_idx = rule_idx;
        this->idx_into_rule = idx_into_rule;
        this->left = left;
        this->pivot = pivot;
        this->right = right;
        return this
    }
    fun copy_construct(old: *BS): void {
        this->nonterminal = old->nonterminal;
        this->rule_idx = old->rule_idx;
        this->idx_into_rule = old->idx_into_rule;
        this->left = old->left;
        this->pivot = old->pivot;
        this->right = old->right;
    }
    fun destruct(): void { }
    fun operator=(other:ref BS):void {
        destruct()
        copy_construct(&other)
    }
    fun to_string(): str {
        return str("nonterminal:") + nonterminal + " rule_idx:" + rule_idx + " idx_into_rule:" + idx_into_rule + " l:" + left + " p:" + pivot + " r:" + right
    }
    fun operator==(rhs: ref BS): bool {
        return nonterminal == rhs.nonterminal && rule_idx == rhs.rule_idx && idx_into_rule == rhs.idx_into_rule && left == rhs.left && pivot == rhs.pivot && right == rhs.right
    }
}
fun bs(nonterminal: int, rule_idx: int, idx_into_rule: int, left: int, pivot: int, right: int): BS {
    var to_ret.construct(nonterminal, rule_idx, idx_into_rule, left, pivot, right): BS
    return to_ret
}
fun fungll(grammer: ref Grammer, input: ref str): set<BS> {
    var R = descend(grammer, grammer.start_symbol, 0)
    var U = set<Descriptor>()
    var G = map<pair<int, int>, set<Pending>>()
    var P = map<pair<int,int>, set<int>>()
    var Y = set<BS>()
    while R.size() != 0 {
        var d = R.pop()
        var it = process(grammer, input, d, G, P)
        var Rp = it.first.first
        var Yp = it.first.second
        var Gp = it.second
        var Pp = it.third

        var U_with_d = U.union(set(d));
        var nextR = R.union(Rp) - U_with_d
        R = nextR
        U = U_with_d
        for (var i = 0; i < Gp.keys.size; i++;) {
            if G.contains_key(Gp.keys[i]) {
                G[Gp.keys[i]].add(Gp.values[i])
            } else {
                G[Gp.keys[i]] = Gp.values[i]
            }
        }
        for (var i = 0; i < Pp.keys.size; i++;) {
            if P.contains_key(Pp.keys[i]) {
                P[Pp.keys[i]].add(Pp.values[i])
            } else {
                P[Pp.keys[i]] = Pp.values[i]
            }
        }
        Y += Yp
    }
    return Y
}
fun descend(grammer: ref Grammer, symbol: int, l: int): set<Descriptor> {
    var to_ret = set<Descriptor>()
    for (var rhs = 0; rhs < grammer.get_nonterminal_rules(symbol).size; rhs++;)
        to_ret.add(descriptor(symbol, rhs, 0, l, l))
    return to_ret
}
fun process(grammer: ref Grammer, input: ref str, descript: Descriptor, G: ref map<pair<int, int>, set<Pending>>, P: ref map<pair<int,int>, set<int>>): triple<pair<set<Descriptor>, set<BS>>, map<pair<int, int>, set<Pending>>, map<pair<int,int>, set<int>>> {
    // if at end / end is emptystr
    if descript.idx_into_rule == grammer.get_nonterminal_rules(descript.nonterminal)[descript.rule_idx].size {
        return process_e(grammer, descript, G, P)
    } else {
        return process_symbol(grammer, input, descript, G, P)
    }
}
fun process_e(grammer: ref Grammer, descript: Descriptor, G: ref map<pair<int, int>, set<Pending>>, P: ref map<pair<int,int>, set<int>>): triple<pair<set<Descriptor>, set<BS>>, map<pair<int, int>, set<Pending>>, map<pair<int,int>, set<int>>> {
    var nonterminal: int
    var rule_idx: int
    var left: int
    var pivot: int
    var X = descript.nonterminal
    var l = descript.left;
    var k = descript.pivot;
    var K = G.get_with_default(make_pair(X,l), set<Pending>())
    var it = ascend(l,K,k)
    var R = it.first
    var Y = it.second
    if grammer.get_nonterminal_rules(X)[descript.rule_idx].size == 0 {
        Y.add(bs(X,descript.rule_idx, 0, l, l, l))
    }
    return make_triple(make_pair(R,Y), map<pair<int, int>, set<Pending>>(), map(make_pair(X,l), set(k)))
}
fun process_symbol(grammer: ref Grammer, input: ref str, descript: Descriptor, G: ref map<pair<int, int>, set<Pending>>, P: ref map<pair<int,int>, set<int>>): triple<pair<set<Descriptor>, set<BS>>, map<pair<int, int>, set<Pending>>, map<pair<int,int>, set<int>>> {
    var s = grammer.get_nonterminal_rules(descript.nonterminal)[descript.rule_idx][descript.idx_into_rule]
    var k = descript.pivot
    var R = P.get_with_default(make_pair(s,k), set<int>())
    var Gp = map(make_pair(s,k), set(pending(descript.nonterminal, descript.rule_idx, descript.idx_into_rule+1, descript.left)))
    if grammer.is_terminal(s) {
        return make_triple(matc(grammer,input,descript), map<pair<int,int>, set<Pending>>(), map<pair<int,int>, set<int>>())
    } else if R.size() == 0 { // s in N
        return make_triple(make_pair(descend(grammer,s,k), set<BS>()), Gp, map<pair<int,int>, set<int>>())
    } else { // s in N and R != set()
        return make_triple(skip(k,pending(descript.nonterminal, descript.rule_idx, descript.idx_into_rule+1, descript.left), R), Gp, map<pair<int,int>, set<int>>())
    }
}
fun matc(grammer: ref Grammer, input: ref str, descript: Descriptor): pair<set<Descriptor>, set<BS>> {
    /*println("trying to match " + grammer.to_string(grammer.get_nonterminal_rules(descript.nonterminal)[descript.rule_idx][descript.idx_into_rule]))*/
    var match_length = grammer.match_terminal(grammer.get_nonterminal_rules(descript.nonterminal)[descript.rule_idx][descript.idx_into_rule], input, descript.pivot)
    if match_length > 0 {
        /*println("matched " + grammer.to_string(grammer.get_nonterminal_rules(descript.nonterminal)[descript.rule_idx][descript.idx_into_rule]))*/
        return make_pair(set(descriptor(descript.nonterminal, descript.rule_idx, descript.idx_into_rule+1, descript.left, descript.pivot+match_length)), set(bs(descript.nonterminal, descript.rule_idx, descript.idx_into_rule+1, descript.left, descript.pivot, descript.pivot+match_length)))
    } else {
        return make_pair(set<Descriptor>(), set<BS>())
    }
}
fun skip(k: int, c: Pending, R: ref set<int>): pair<set<Descriptor>, set<BS>> { return nmatch(k, set(c), R); }
fun ascend(k:int, K: ref set<Pending>, r: int): pair<set<Descriptor>, set<BS>> { return nmatch(k, K, set(r)); }
fun nmatch(k:int, K: ref set<Pending>, R: ref set<int>): pair<set<Descriptor>, set<BS>> {
    var Rp = set<Descriptor>()
    var Y = set<BS>()
    for (var i = 0; i < K.data.size; i++;) {
        var pending = K.data[i]
        for (var j = 0; j < R.data.size; j++;) {
            var r = R.data[j]
            Rp.add(descriptor(pending.nonterminal, pending.rule_idx, pending.idx_into_rule, pending.left, r))
            Y.add(bs(pending.nonterminal, pending.rule_idx, pending.idx_into_rule, pending.left, k, r))
        }
    }
    return make_pair(Rp,Y)
}
/*fun main(argc: int, argv: **char): int {*/
    /*var grammer.construct(): Grammer*/
    /*var one = grammer.add_terminal("12")*/
    /*var E = grammer.add_new_nonterminal("E", vec<int>())*/
    /*grammer.add_to_nonterminal(E, vec(one))*/
    /*grammer.add_to_nonterminal(E, vec(E,E,E))*/

    /*var BSR = fungll(grammer, str("1212"))*/
    /*println(str("length of BSR is: ") + BSR.size())*/
    /*for (var i = 0; i < BSR.data.size; i++;) {*/
        /*var BS = BSR.data[i]*/
        /*println(str() + i + ": " + grammer.to_string(BSR.data[i]))*/
    /*}*/

    /*return 0*/
/*}*/