#include "map.h"

#include <algorithm>
#include <iostream>

#include "constants.h"

game_map::game_map(character *player, RNG *rng, const feature enabled_features):
        enabled_features{enabled_features} {
        map.reserve(MAP_HEIGHT * MAP_WIDTH);

        for (int i = MAP_HEIGHT * MAP_WIDTH; i > 0; --i)
                map.push_back(' ');

        // Note: during generation, walls DO NOT count as being in the rooms
        std::vector<std::pair<position, int>> room_dims = gen_room_dims(rng);

        std::vector<std::pair<position, int>> layer_data;
        // width height top left
        room_data = distr_rooms(rng, room_dims, layer_data);

        for (size_t r = 0; r < room_data.size(); ++r)
                fill_room(room_data[r], r);

        fill_outline();

        gen_path(layer_data, rng);

        rooms_tile_list.reserve(room_data.size());

        for (size_t i = 0; i < room_data.size(); ++i)
                rooms_tile_list.push_back({});

        for (size_t i = 0; i < map.size(); ++i)
                if (map[i] >= 0 && map[i] < MAX_ROOM_CNT)
                        rooms_tile_list[map[i]].push_back(remap_index(i));

        for (size_t i = 0; i < rooms_tile_list.size(); ++i)
                rooms_tile_list[i].shrink_to_fit();

        rooms_tile_list.shrink_to_fit();

        int player_room = rng->rand_under(room_data.size());
        player->set_pos(rng->get_rand_in_vector(rooms_tile_list[player_room]));

        gen_stairs(player_room, rng);
}

void game_map::gen_stairs(int player_room, RNG *rng) {
        down_stairs = rng->get_rand_in_vector(rooms_tile_list[
                        rng->exclude_middle(0, room_data.size(), player_room)]);

        if (enabled_features & FEATURE_REVISIT) {
                up_stairs = rng->get_rand_in_vector(rooms_tile_list[player_room]);

                map[remap_position(up_stairs)] = '<';
                map[remap_position(down_stairs)] = '>';
        } else {
                map[remap_position(down_stairs)] = '\\';
        }

}

position game_map::random_size(int min_width, int min_height,
                               int max_width, int max_height,
                               RNG *rng) {
        return {rng->rand_between(min_width, max_width + 1),
                rng->rand_between(min_height, max_height + 1)};
}

game_map::game_map(character *player, const std::string &map_data,
                   RNG *rng, const feature enabled_features):
        enabled_features{enabled_features} {
        int map_size = MAP_HEIGHT * MAP_WIDTH;
        map.reserve(map_size);
        rooms_tile_list.reserve(MAX_ROOM_CNT);

        for (int i = 0; i < MAX_ROOM_CNT; ++i)
                rooms_tile_list.push_back({});

        int max_room_num = 0;

        for (int i = 0; i < map_size; ++i) {
                if (map_data[i] >= '0' && map_data[i] <= '9') {
                        map.push_back(map_data[i] - '0');
                        max_room_num = std::max(max_room_num, map_data[i] - '0');
                } else {
                        map.push_back(map_data[i]);
                }

                if (map_data[i] >= '0' && map_data[i] <= '9')
                        rooms_tile_list[map_data[i] - '0'].push_back(remap_index(i));
        }

        for (int i = 0; i <= max_room_num; ++i)
                room_data.push_back({0, 0, 0, 0});

        int player_room = rng->rand_under(room_data.size());
        player->set_pos(rng->get_rand_in_vector(rooms_tile_list[player_room]));

        gen_stairs(player_room, rng);

}

bool game_map::is_available(const position &pos) const {
        if (pos.x < 0 || pos.x >= MAP_WIDTH || pos.y < 0 || pos.y >= MAP_HEIGHT)
                return false;

        int idx = remap_position(pos);
        return map[idx] < MAX_ROOM_CNT || map[idx] == '\\' || map[idx] == '>' ||
               map[idx] == '<' || map[idx] == '+' || map[idx] == '#';
}

position_list game_map::get_available_around(const position &pos) const {
        position_list result;

        for (int i = 0; i < DIRECTION_CNT; ++i)
                if (is_available(pos + MOVE[i]))
                        result.push_back(pos + MOVE[i]);

        return result;
}

void game_map::print(display *out) const {
        for (std::size_t i = 0; i < map.size(); ++i)
                out->print_char(remap_index(i), map[i] <= 9 ? '.' : map[i],
                                map[i] == '\\' || map[i] == '>' ||
                                map[i] == '<' ? COLOR_PAIR(COLOR_BLUE) : A_NORMAL);
}

int game_map::which_room(const position &pos) const {
        if (pos.y > MAP_HEIGHT || pos.x > MAP_WIDTH || pos.x < 0 || pos.y < 0)
                return -1;

        char tmp = map[remap_position(pos)];
        return tmp < MAX_ROOM_CNT ? tmp : -1;
}

position game_map::get_up_stairs() const {
        return up_stairs;
}

position game_map::get_down_stairs() const {
        return down_stairs;
}

int game_map::get_up_stairs_room() const {
        return map[remap_position(up_stairs)];
}

int game_map::get_down_stairs_room() const {
        return map[remap_position(down_stairs)];
}

position_list game_map::get_room_list(int idx) const {
        return rooms_tile_list[idx];
}

std::vector<position_list> game_map::get_room_list() const {
        return rooms_tile_list;
}

std::vector<std::pair<position, int>> game_map::gen_room_dims(RNG *rng) {
        position_list room_dim_list;
        room_dim_list.reserve(MAX_ROOM_CNT);
        std::vector<std::pair<position, int>> result;
        result.reserve(MAX_ROOM_CNT);

        for (int i = 0; i < MAX_ROOM_CNT; ++i)
                room_dim_list.push_back(random_size(MIN_ROOM_WIDTH, MIN_ROOM_HEIGHT,
                                                    MAX_ROOM_WIDTH, MAX_ROOM_HEIGHT,
                                                    rng));

        int curr_top  = 0;
        int curr_left = 0;
        // index in result
        int curr_layer_idx = 0;
        int curr_layer_cnt = 0;

        for (int i = 0; i < MAX_ROOM_CNT &&
             curr_top <= ACTUAL_MAP_HEIGHT &&
             curr_left <= ACTUAL_MAP_WIDTH; ++i) {
                // DO NOT update curr_top until curr_left is exhausted
                if (curr_top + MIN_ROOM_SPACING +
                    room_dim_list[i].y + HEIGHT_RESERVED <= ACTUAL_MAP_HEIGHT &&
                    curr_left + MIN_ROOM_SPACING +
                    room_dim_list[i].x + WIDTH_RESERVED <= ACTUAL_MAP_WIDTH) {
                        result.push_back({room_dim_list[i], curr_layer_cnt});
                        curr_left += MIN_ROOM_SPACING + room_dim_list[i].x;
                        continue;
                }

                int tmp = curr_top;

                for (std::size_t j = curr_layer_idx; j < result.size(); ++j)
                        tmp = std::max(curr_top + result[j].first.y + MIN_ROOM_SPACING,
                                       tmp);

                curr_top = tmp;
                curr_layer_idx = result.size();
                curr_left = 0;
                ++curr_layer_cnt;

                if (curr_top + MIN_ROOM_SPACING +
                    room_dim_list[i].y + HEIGHT_RESERVED <= ACTUAL_MAP_HEIGHT &&
                    curr_left + MIN_ROOM_SPACING +
                    room_dim_list[i].x + WIDTH_RESERVED <= ACTUAL_MAP_WIDTH) {
                        result.push_back({room_dim_list[i], curr_layer_cnt});
                        curr_left += MIN_ROOM_SPACING + room_dim_list[i].x;
                }
        }

        result.shrink_to_fit();

        return result;
}

position random_size(int min_width, int min_height,
                     int max_width, int max_height,
                     RNG *rng) {
        return {rng->rand_between(min_width, max_width + 1),
                rng->rand_between(min_height, max_height + 1)};
}

void game_map::fill_room(const room &r, const int num) {
        for (int x = 0; x < r.width; ++x)
                for (int y = 0; y < r.height; ++y)
                        map[remap_position({r.left + x,
                                            r.top + y})] = num;

        for (int x = 0; x < r.width; ++x) {
                map[remap_position({r.left + x,
                                    r.top - 1})] = '-';
                map[remap_position({r.left + x,
                                    r.top +
                                    r.height})] = '-';
        }

        for (int y = -1; y <= r.height; ++y) {
                map[remap_position({r.left - 1,
                                    r.top + y})] = '|';
                map[remap_position({r.left +
                                    r.width,
                                    r.top + y})] = '|';
        }
}

std::vector<game_map::room> game_map::distr_rooms(RNG *rng,
                std::vector<std::pair<position, int>> &room_dims,
                std::vector<std::pair<position, int>> &layer_data) {
        std::vector<room> result;
        result.reserve(room_dims.size());

        int max_layer = room_dims[room_dims.size() - 1].second;
        // left, right, height
        layer_data.reserve(max_layer + 1);

        // distributing rooms horizontally
        for (int layer = 0; layer <= max_layer; ++layer) {
                int l = INF;
                int r = 0;
                int layer_height = 0;

                // get the interval for the current layer
                //  and the max height of the layer
                for (std::size_t i = 0; i < room_dims.size(); ++i)
                        if (room_dims[i].second == layer) {
                                l = std::min(l, (int)i);
                                r = std::max(r, (int)i);
                                layer_height = std::max(layer_height,
                                                        room_dims[i].first.y);
                        }

                layer_data.push_back({{l, r}, layer_height});

                // distribute the current layer
                if (l == r) {
                        result.push_back({
                                0, rng->rand_under(ACTUAL_MAP_WIDTH -
                                room_dims[l].first.x + 1),
                                room_dims[l].first.x,
                                room_dims[l].first.y, {0, 0}, {0, 0}});
                        continue;
                }

                int left = 0;
                int right = ACTUAL_MAP_WIDTH;

                // every time, distribute the last one first
                for (int i = l; i < r; ++i)
                        left += MIN_ROOM_SPACING + room_dims[i].first.x;

                for (int i = r; i >= l; --i) {
                        int offset = rng->rand_between(left, right - room_dims[i].first.x + 1);
                        result.push_back({0, offset,
                                          room_dims[i].first.x,
                                          room_dims[i].first.y, {0, 0}, {0, 0}});

                        right = offset - MIN_ROOM_SPACING;

                        if (i != l)
                                left -= MIN_ROOM_SPACING + room_dims[i - 1].first.x;
                }
        }

        // distributing rooms vertically
        int top = 0;
        int bottom = ACTUAL_MAP_HEIGHT;

        for (int i = 0; i < max_layer; ++i)
                top += MIN_ROOM_SPACING + layer_data[i].second;

        for (int i = max_layer; i >= 0; --i) {
                int offset = rng->rand_between(top,
                                               bottom - layer_data[i].second + 1);

                for (int j = layer_data[i].first.x;
                     j <= layer_data[i].first.y; ++j)
                        result[j].top = offset;

                bottom = offset - MIN_ROOM_SPACING;

                if (i != 0)
                        top -= MIN_ROOM_SPACING + layer_data[i - 1].second;
        }

        // add some vertical jitter
        jitter(rng, result);

        //add padding
        for (std::size_t i = 0; i < result.size(); ++i) {
                result[i].top += MAP_PADDING;
                result[i].left += MAP_PADDING;
        }

        return result;
}

void game_map::jitter(RNG *rng,
                      std::vector<room> &rooms) {
        for (int n = rooms.size() - 1; n >= 0; --n) {
                int t = 0;
                int b = ACTUAL_MAP_HEIGHT - 1;

                for (std::size_t i = 0; i < rooms.size(); ++i) {
                        if (rooms[i] == rooms[n])
                                continue;

                        if (overlap_x(rooms[n], rooms[i])) {
                                if (rooms[n].top > rooms[i].top)
                                        t = std::max(t,
                                                     rooms[i].top +
                                                     rooms[i].height +
                                                     MIN_ROOM_SPACING);
                                else
                                        b = std::min(b,
                                                     rooms[i].top -
                                                     MIN_ROOM_SPACING);
                        }
                }

                if (t < b - rooms[n].height + 1)
                        rooms[n].top = rng->rand_between(t,
                                                         b - rooms[n].height + 1);
        }
}

bool game_map::overlap_x(room &room1,
                         room &room2) {
        return (room1.left >= room2.left &&
                room1.left - MIN_ROOM_SPACING <=
                room2.left + room2.width) ||
               (room2.left >= room1.left &&
                room2.left - MIN_ROOM_SPACING <=
                room1.left + room1.width);
}

bool game_map::overlap_y(room &room1,
                         room &room2) {
        return (room1.top >= room2.top &&
                room1.top - MIN_ROOM_SPACING <=
                room2.top + room2.height) ||
               (room2.top >= room1.top &&
                room2.top - MIN_ROOM_SPACING <=
                room1.top + room1.height);
}

void game_map::fill_outline() {
        for (int x = 0; x < MAP_WIDTH; ++x) {
                map[remap_position({x, 0})] = '-';
                map[remap_position({x, MAP_HEIGHT - 1})] = '-';
        }


        for (int y = 0; y < MAP_HEIGHT; ++y) {
                map[remap_position({0, y})] = '|';
                map[remap_position({MAP_WIDTH - 1, y})] = '|';
        }
}

int game_map::get_room_cnt() const {
        return room_data.size();
}

game_map::room game_map::get_room(std::size_t idx) const {
        if (idx < room_data.size())
                return room_data[idx];

        return {0, 0, 0, 0, {0, 0}, {0, 0}};
}

void game_map::gen_path(std::vector<std::pair<position, int>> &layer_data,
                        RNG *rng) {
        for (std::size_t l = 0; l < layer_data.size(); ++l) {
                for (int i = layer_data[l].first.x; i < layer_data[l].first.y; ++i)
                        connect_x(room_data[i + 1], room_data[i], rng);

                if (l < layer_data.size() - 1) {
                        connect_y(room_data[layer_data[l].first.x],
                                  room_data[layer_data[l + 1].first.x], rng);
                        connect_y(room_data[layer_data[l].first.y],
                                  room_data[layer_data[l + 1].first.y], rng);
                        connect_y(room_data[(layer_data[l].first.x +
                                             layer_data[l].first.y) / 2],
                                  room_data[(1 + layer_data[l + 1].first.x +
                                             layer_data[l + 1].first.y) / 2], rng);
                }
        }
}

void game_map::connect_x(room &room1, room &room2, RNG *rng) {
        room1.rdoor = {room1.left + room1.width,
                       rng->rand_between(room1.top, room1.top + room1.height)
                      };
        room2.ldoor = {room2.left - 1,
                       rng->rand_between(room2.top, room2.top + room2.height)
                      };
        map[remap_position(room1.rdoor)] = '+';
        map[remap_position(room2.ldoor)] = '+';
        connect({room1.rdoor.x + 1, room1.rdoor.y},
        {room2.ldoor.x - 1, room2.ldoor.y});
}

void game_map::connect_y(room &room1, room &room2, RNG *rng) {
        room1.bdoor = {rng->rand_between(room1.left, room1.left + room1.width),
                       room1.top + room1.height
                      };
        room2.tdoor = {rng->rand_between(room2.left, room2.left + room2.width),
                       room2.top - 1
                      };
        map[remap_position(room1.bdoor)] = '+';
        map[remap_position(room2.tdoor)] = '+';
        connect({room1.bdoor.x, room1.bdoor.y + 1},
        {room2.tdoor.x, room2.tdoor.y - 1});
}

// a is to the left of b
void game_map::connect(position s, position t) {
        if (s.x > t.x) {
                connect(t, s);
                return;
        }

        map[remap_position(s)] = '#';
        map[remap_position(t)] = '#';

        const room nil{0, 0, 0, 0};

        while (s.x < t.x) {
                auto r = hit_room({s.x + 1, s.y});

                if (r == nil) {
                        ++s.x;
                        map[remap_position(s)] = '#';
                        continue;
                }

                if (r.top + r.height - s.y < r.top - 1) {
                        while (hit_room({s.x + 1, s.y}, r)) {
                                ++s.y;
                                map[remap_position(s)] = '#';
                        }
                } else {
                        while (hit_room({s.x + 1, s.y}, r)) {
                                --s.y;
                                map[remap_position(s)] = '#';
                        }
                }
        }

        if (s.y < t.y) {
                while (s.y < t.y) {
                        auto r = hit_room({s.x, s.y + 1});

                        if (r == nil) {
                                ++s.y;
                                map[remap_position(s)] = '#';
                                continue;
                        }

                        while (hit_room({s.x, s.y + 1}, r)) {
                                ++s.x;
                                map[remap_position(s)] = '#';
                        }

                        while (hit_room({s.x - 1, s.y + 1}, r)) {
                                ++s.y;
                                map[remap_position(s)] = '#';
                        }

                        while (hit_room({s.x, s.y - 1}, r) && s.x > t.x) {
                                --s.x;
                                map[remap_position(s)] = '#';
                        }
                        ++s.y;
                        map[remap_position(s)] = '#';
                }
        } else {
                while (s.y > t.y) {
                        auto r = hit_room({s.x, s.y - 1});

                        if (r == nil) {
                                --s.y;
                                map[remap_position(s)] = '#';
                                continue;
                        }

                        while (hit_room({s.x, s.y - 1}, r)) {
                                ++s.x;
                                map[remap_position(s)] = '#';
                        }

                        while (hit_room({s.x - 1, s.y - 1}, r)) {
                                --s.y;
                                map[remap_position(s)] = '#';
                        }

                        while (hit_room({s.x, s.y + 1}, r) && s.x > t.x) {
                                --s.x;
                                map[remap_position(s)] = '#';
                        }
                }
        }
}

game_map::room game_map::hit_room(const position &a) {
        for (auto r : room_data) {
                if (hit_room(a, r))
                        return r;
        }

        const room nil{0, 0, 0, 0};
        return nil;
}

bool game_map::hit_room(const position &a, const room &r) {
        return a.y >= r.top - 1 && a.y <= r.top + r.height &&
               a.x >= r.left - 1 && a.x <= r.left + r.width;
}

position game_map::remap_index(const int idx) const {
        return {idx % MAP_WIDTH, idx / MAP_WIDTH};
}

int game_map::remap_position(const position &pos) const {
        return pos.y * MAP_WIDTH + pos.x;
}