#include "terrain.h"
#include <random>
#include <assert.h>
#include <functional>

using namespace std;

BadImportTerrainConfig::BadImportTerrainConfig(size_t pt):pt(pt){}

const char* BadImportTerrainConfig::what() const noexcept{
    return ("ImportTerrainConfig "+to_string(pt)).c_str();
}

const char* BadCapitalAssign::what() const noexcept{
    return "Bad Capital Assign";
}

inline namespace{
    mt19937 rnd(19260817);
    enum class VertexType:std::uint8_t{
        Ordinary,Mountain,Capital,Cut
    };
    bool ban(VertexType t){return t==VertexType::Mountain||t==VertexType::Capital;}
    template<typename T> void upmin(T &x,const T &y){if(y<x)x=y;}
    pair<bool,vector<Point>> generateCapital(pos_t w,pos_t h,vector<vector<VertexType>> &vertex_type,int r){
        auto findCut=[&](){
            int idx=0; vector<vector<int>> dfn(h,vector<int>(w)),low=dfn;
            function<void(int,int,int,int,bool)> tarjan=[&](int x,int y,int fx,int fy,bool rt){
                dfn[x][y]=low[x][y]=++idx;
                int ch=0;
                for(int i=0;i<4;i++){
                    static const int dx[]={0,0,-1,1},dy[]={-1,1,0,0};
                    const int xx=x+dx[i],yy=y+dy[i];
                    if(xx<0||xx>=h||yy<0||yy>=w) continue;
                    if(vertex_type[xx][yy]==VertexType::Capital) vertex_type[x][y]=VertexType::Cut;
                    if(ban(vertex_type[xx][yy])||(xx==fx&&yy==fy)) continue;
                    if(!dfn[xx][yy]){
                        ch++;
                        tarjan(xx,yy,x,y,0);
                        upmin(low[x][y],low[xx][yy]);
                        if(!rt&&low[xx][yy]>=dfn[x][y]) vertex_type[x][y]=VertexType::Cut;
                    }
                    else upmin(low[x][y],dfn[xx][yy]);
                }
                if(rt&&ch>=2) vertex_type[x][y]=VertexType::Cut;
            };
            bool flag=0;
            for(pos_t i=0;i<h;i++){
                for(pos_t j=0;j<w;j++){
                    if(!ban(vertex_type[i][j])&&!dfn[i][j]){
                        if(flag) return false;
                        flag=1,tarjan(i,j,-1,-1,1);
                    }
                }
            }
            return true;
        };
        vector<Point> res(r);
        for(int i=0;i<=r;i++){
            if(!findCut()) return {false,vector<Point>()};
            if(i==r) break;
            vector<Point> options;
            for(pos_t x=0;x<h;x++){
                for(pos_t y=0;y<w;y++){
                    if(vertex_type[x][y]==VertexType::Ordinary) options.emplace_back(x,y);
                    if(vertex_type[x][y]==VertexType::Cut) vertex_type[x][y]=VertexType::Ordinary;
                }
            }
            if(options.empty()) return {false,vector<Point>()};
            res[i]=options[rnd()%options.size()];
            vertex_type[res[i].x][res[i].y]=VertexType::Capital;
        }
        return {true,res};
    }
}

GameBoard ImportedTerrain::makeGameBoard(const InitInfo &init_info){
    auto perm=[](std::uint8_t n){
        vector<std::uint8_t> vec(n);
        iota(vec.begin(),vec.end(),0);
        shuffle(vec.begin(),vec.end(),rnd);
        return vec;
    };
    GameBoard g(w,h,init_info);
    for(pos_t i=0;i<h;i++){
        for(pos_t j=0;j<w;j++){
            g.at(i,j).type=tiles[i][j].type;
            g.at(i,j).unit=tiles[i][j].unit;
        }
    }
    auto arrange=[&perm,&g](const vector<Player> &players,const vector<vector<Point>> &capitals,vector<Player> &rest){
        vector<Point> caps;
        for(const auto &v:capitals){
            for(const auto &p:v) caps.push_back(p);
            if(caps.size()>=players.size()) break;
        }
        auto C=perm(players.size()),D=perm(caps.size());
        for(size_t j=D.size();j<C.size();j++)
            rest.push_back(players[C[j]]);
        for(size_t j=0;j<min(C.size(),D.size());j++){
            g.at(caps[D[j]].x,caps[D[j]].y).type=TileType::Capital;
            g.at(caps[D[j]].x,caps[D[j]].y).owner=players[C[j]];
        }
    };
    vector<vector<Player>> players(g.numTeams());
    for(int i=1,n=g.numPlayers();i<=n;i++)
        players[g.teamOf(i)-1].push_back(i);
    auto A=perm(players.size()),B=perm(capitals.size()-1);
    vector<Player> rest1;
    for(size_t i=B.size();i<A.size();i++)
        for(auto id:players[A[i]]) rest1.push_back(id);
    for(size_t i=0;i<min(A.size(),B.size());i++)
        arrange(players[A[i]],capitals[B[i]],rest1);
    vector<Player> rest2;
    arrange(rest1,capitals.back(),rest2);
    int T=5;
    while(T--){
        vector<vector<VertexType>> vertex_type(h,vector<VertexType>(w,VertexType::Ordinary));
        for(pos_t i=0;i<h;i++){
            for(pos_t j=0;j<w;j++){
                if(g.at(i,j).type==TileType::Mountain) vertex_type[i][j]=VertexType::Mountain;
                if(g.at(i,j).type==TileType::Capital) vertex_type[i][j]=VertexType::Capital;
            }
        }
        auto pr=generateCapital(w,h,vertex_type,rest2.size());
        if(!pr.first) continue;
        for(size_t i=0;i<rest2.size();i++){
            g.at(pr.second[i].x,pr.second[i].y).type=TileType::Capital;
            g.at(pr.second[i].x,pr.second[i].y).owner=rest2[i];
        }
        return g;
    }
    throw BadCapitalAssign();
}

ImportedTerrain importTerrain(const ImportTerrainConfig &in){
    ImportedTerrain t;
    t.w=in.w,t.h=in.h;
    t.tiles.resize(t.h,vector<ImportedTerrain::TerrainTile>(t.w));
    size_t pt=0;
    auto error=[&](){throw BadImportTerrainConfig(pt);};
    auto view=[&](char c){return pt<in.value.size()&&in.value[pt]==c?(pt++,true):false;};
    auto jump=[&](char c){if(!view(c)) error();};
    auto read=[&](int l=-99999,int r=99999){
        bool neg=view('-');
        if(!(pt<in.value.size()&&isdigit(in.value[pt]))) error();
        std::int32_t x=0;
        while(pt<in.value.size()&&isdigit(in.value[pt])){
            x=x*10+(in.value[pt]^'0');
            if(x>99999) error(); pt++;
        }
        if(neg) x=-x;
        if(x<l||x>r) error();
        return x;
    };
    static vector<Point> vec[27][101];
    for(pos_t i=0;i<t.h;i++){
        for(pos_t j=0;j<t.w;j++){
            auto &p=t.tiles[i][j];
            if(view(' ')) p.type=TileType::Blank;
            else if(view('m')) p.type=TileType::Mountain;
            else if(view('n')){
                p.type=TileType::Blank;
                p.unit=read();
            }
            else if(view('s')) p.type=TileType::Swamp;
            else if(view('g')){
                p.type=TileType::Blank;
                bool tag=1;
                int team=(pt<in.value.size()&&isupper(in.value[pt])?in.value[pt++]-'A':(tag=view(' '),26));
                int priority=(tag&&pt<in.value.size()&&isdigit(in.value[pt])?read(1,99):100);
                vec[team][priority].emplace_back(i,j);
            }
            else{
                p.type=TileType::Stronghold;
                p.unit=read();
            }
            if(i+1<t.h||j+1<t.w) jump(',');
        }
    }
    if(pt!=in.value.size()) error();
    t.capitals.emplace_back();
    for(int i=0;i<=26;i++){
        for(int j=100;j>=1;j--){
            if(!vec[i][j].empty()){
                t.capitals.back().emplace_back().swap(vec[i][j]);
            }
        }
        if(!t.capitals.back().empty()&&i!=26){
            t.capitals.emplace_back();
        }
    }
    return t;
}