#include "render.h"
#include "game.h"
#include "anim.h"

#include <gint/display.h>

//---
// Camera management
//---

void camera_init(camera_t *c, map_t const *m)
{
    c->zoom = 1;

    c->limits.x_min = fix(-CAMERA_BORDER);
    c->limits.x_max = fix(m->width + CAMERA_BORDER);
    c->limits.y_min = fix(-CAMERA_BORDER);
    c->limits.y_max = fix(m->height + CAMERA_BORDER);

    /* Fullscreen */
    c->viewport.x_min = 0;
    c->viewport.x_max = DWIDTH;
    c->viewport.y_min = 0;
    c->viewport.y_max = DHEIGHT;

    c->width  = fix(c->viewport.x_max - c->viewport.x_min) / TILE_WIDTH;
    c->height = fix(c->viewport.y_max - c->viewport.y_min) / TILE_HEIGHT;

    c->x = (c->limits.x_min + c->limits.x_max) / 2;
    c->y = (c->limits.y_min + c->limits.y_max) / 2;

    /* Slightly off-center to add space for the HUD */
    c->y -= fix(0.5);
}

ipoint_t camera_map2screen(camera_t const *c, fpoint_t p)
{
    return (ipoint_t){
        .x = DWIDTH  / 2 + fround((p.x - c->x) * TILE_WIDTH  * c->zoom),
        .y = DHEIGHT / 2 + fround((p.y - c->y) * TILE_HEIGHT * c->zoom),
    };
}
/* Translate screen coordinates to map coordinates */
fpoint_t camera_screen2map(camera_t const *c, ipoint_t p)
{
    return (fpoint_t){
        .x = c->x + fix(p.x - DWIDTH  / 2) / TILE_WIDTH  / c->zoom,
        .y = c->y + fix(p.y - DHEIGHT / 2) / TILE_HEIGHT / c->zoom,
    };
}

/* Lock the camera at the center if set by settings. */
static bool camera_lock(camera_t *c)
{
    if(c->zoom == 1 && CAMERA_LOCK_AT_x1)
    {
        c->x = (c->limits.x_min + c->limits.x_max) / 2;
        c->y = (c->limits.y_min + c->limits.y_max) / 2;
        return true;
    }
    return false;
}

/* Bound the camera to the map limits */
static void camera_bound(camera_t *c)
{
    /* Project top left and bottom-right corners of viewport onto the map */
    ipoint_t v_tl = { c->viewport.x_min, c->viewport.y_min };
    ipoint_t v_br = { c->viewport.x_max, c->viewport.y_max };

    fpoint_t m_tl = camera_screen2map(c, v_tl);
    fpoint_t m_br = camera_screen2map(c, v_br);

    /* Bound viewport to map limits */
    if(m_tl.x < c->limits.x_min)
        c->x += (c->limits.x_min - m_tl.x);
    else if(m_br.x > c->limits.x_max)
        c->x += (c->limits.x_max - m_br.x);
    if(m_tl.y < c->limits.y_min)
        c->y += (c->limits.y_min - m_tl.y);
    else if(m_br.y > c->limits.y_max)
        c->y += (c->limits.y_max - m_br.y);
}

void camera_move(camera_t *c, map_coord_t dx, map_coord_t dy)
{
    if(camera_lock(c)) return;
    c->x += dx;
    c->y += dy;
    camera_bound(c);
}

void camera_zoom(camera_t *c, int zoom)
{
    if(zoom < ZOOM_MIN) zoom = ZOOM_MIN;
    if(zoom > ZOOM_MAX) zoom = ZOOM_MAX;

    c->zoom = zoom;
    if(camera_lock(c)) return;
    camera_bound(c);
}

fixed_t camera_ppu(camera_t const *c)
{
    /* Since this assumes isotropic space we can use TILE_WIDTH or TILE_HEIGHT
       indifferently (they're assumed equal) */
    return fix(1) * c->zoom * TILE_WIDTH;
}

//---
// Rendering
//---

void render_map(map_t const *m, camera_t const *c)
{
    extern bopti_image_t img_tileset_base;
    extern bopti_image_t img_tileset_decor;

    /* Render floor and walls */
    for(int row = -2; row < m->height + 1; row++)
    for(int col = -1; col < m->width + 1; col++) {
        struct tile *t = map_tile(m, col, row);
        fpoint_t tile_pos = { fix(col), fix(row) };
        ipoint_t p = camera_map2screen(c, tile_pos);

        if(!t) {
            drect(p.x, p.y, p.x+15, p.y+15, C_BLACK);
            continue;
        }

        /* Floor/wall layer */
        dsubimage(p.x, p.y, &img_tileset_base,
            TILE_WIDTH * (t->base % 16), TILE_HEIGHT * (t->base / 16),
            TILE_WIDTH, TILE_HEIGHT, DIMAGE_NONE);
        /* Decoration layer */
        if(t->decor) dsubimage(p.x, p.y, &img_tileset_decor,
            TILE_WIDTH * (t->decor % 16), TILE_HEIGHT * (t->decor / 16),
            TILE_WIDTH, TILE_HEIGHT, DIMAGE_NONE);
    }
}

static void render_effect_area(effect_area_t const *ea, camera_t const *c,
    bool show_hitboxes)
{
    ipoint_t anchor = camera_map2screen(c, ea->anchor);

    if(ea->anim.frame) {
        fpoint_t top_left = {
            ea->anchor.x + ea->sprite.l,
            ea->anchor.y + ea->sprite.t };
        ipoint_t p = camera_map2screen(c, top_left);
        anim_frame_render(p.x, p.y, ea->anim.frame);
    }
    if(!ea->anim.frame || show_hitboxes) {
        frect_t r = ea->sprite;
        r = rect_scale(r, camera_ppu(c));
        r = rect_translate(r, point_i2f(anchor));
        rect_draw(r, C_RGB(31, 31, 0));
    }
}

void render_game(game_t const *g, bool show_hitboxes)
{
    camera_t const *c = &g->camera;

    render_map(&g->map, &g->camera);

    /* Render background particles */
    for(int i = 0; i < g->particle_count; i++) {
        particle_t *p = g->particles[i];
        if(!particle_is_background(p)) continue;
        ipoint_t center = camera_map2screen(c, p->pos);
        particle_render(center.x, center.y, p);
    }

    /* Render background effect areas */
    for(int i = 0; i < g->effect_area_count; i++) {
        if(!effect_area_is_background(g->effect_areas[i])) continue;
        render_effect_area(g->effect_areas[i], c, show_hitboxes);
    }

    /* Render entities */
    for(int i = 0; i < g->entity_count; i++) {
        entity_t *e = g->entities[i];

        ipoint_t p = camera_map2screen(c, entity_pos(e));

        /* Show entity sprite */
        if(e->anim.frame) {
            anim_frame_render(p.x, p.y, e->anim.frame);
        }
        /* Show entity hitbox in the map coordinate system */
        if(!e->anim.frame || show_hitboxes) {
            frect_t r = e->hitbox;
            r = rect_scale(r, camera_ppu(c));
            r = rect_translate(r, point_i2f(p));
            rect_draw(r, C_BLUE);

            r = e->sprite;
            r = rect_scale(r, camera_ppu(c));
            r = rect_translate(r, point_i2f(p));
            rect_draw(r, C_RGB(12, 12, 12));

            /* Show entity center */
            dline(p.x-1, p.y, p.x+1, p.y, C_BLUE);
            dline(p.x, p.y-1, p.x, p.y+1, C_BLUE);
        }
    }

    /* Render background effect areas */
    for(int i = 0; i < g->effect_area_count; i++) {
        if(effect_area_is_background(g->effect_areas[i])) continue;
        render_effect_area(g->effect_areas[i], c, show_hitboxes);
    }

    /* Render foreground particles */
    for(int i = 0; i < g->particle_count; i++) {
        particle_t *p = g->particles[i];
        if(particle_is_background(p)) continue;
        ipoint_t center = camera_map2screen(c, p->pos);
        particle_render(center.x, center.y, p);
    }

    extern font_t font_rogue;
    font_t const *old_font = dfont(&font_rogue);

    /* Render wave progress bar */
    int enemies_left = 0;
    for(int i = 0; i < g->entity_count; i++)
        enemies_left += (g->entities[i]->identity != 0);

    extern bopti_image_t img_hud_wave, img_hud_wave2;
    dimage((DWIDTH-img_hud_wave.width) / 2, 17, &img_hud_wave);
    dsubimage((DWIDTH-img_hud_wave2.width) / 2, 17, &img_hud_wave2,
        0, 0, (img_hud_wave2.width*enemies_left) /
        g->level->waves[g->wave-1].enemy_count, img_hud_wave2.height,
        DIMAGE_NONE);

    if(g->wave_spawned < game_current_wave(g)->enemy_count)
        dprint_opt(DWIDTH / 2, 2, C_WHITE, C_NONE, DTEXT_CENTER, DTEXT_TOP,
            "Wave %d: %d enemies spawning", g->wave,
                game_current_wave(g)->enemy_count - g->wave_spawned);
    else if(enemies_left > 0)
        dprint_opt(DWIDTH / 2, 2, C_WHITE, C_NONE, DTEXT_CENTER, DTEXT_TOP,
            "Wave %d: %d enemies left", g->wave, enemies_left);
    else
        dprint_opt(DWIDTH / 2, 2, C_WHITE, C_NONE, DTEXT_CENTER, DTEXT_TOP,
            "Wave %d: Victory!", g->wave);

    entity_t const *player = g->player;
    dprint(2,  2, C_WHITE, "HP: %d", player->HP);
    dprint_opt(DWIDTH - 2, 2, C_WHITE, C_NONE, DTEXT_RIGHT, DTEXT_TOP,
        "ATK:%d DEF:%d", player->ATK, player->DEF);

    /* Render skill icons */
    extern bopti_image_t img_skillicons;
    for(int i = 0; i < 6; i++) {
        /* Activity and cooldown */
        fixed_t cooldown_total=0, cooldown_remaining=0;
        if(i == 0 && player->movement.dash < 0) {
            cooldown_total = player->movement_params->dash_cooldown;
            cooldown_remaining = -player->movement.dash;
        }
        else if(i > 0) {
            cooldown_remaining=fix(1);
        }

        int x=15+68*i, y=DHEIGHT-28, bg=(cooldown_remaining!=0);
        dsubimage(x, y, &img_skillicons, 23*bg, 0, 23, 23, DIMAGE_NONE);
        dsubimage(x, y, &img_skillicons, 23*(i+2), 0, 23, 23, DIMAGE_NONE);

        /* Darken the area representing remaining cooldown */
        if(cooldown_total != 0) {
            int height = (cooldown_remaining * 23) / cooldown_total;
            for(int y1 = y+23-height; y1 < y + 23; y1++) {
                for(int x1 = x; x1 < x+23; x1++) {
                    int i = DWIDTH * y1 + x1;
                    gint_vram[i] = ~((~gint_vram[i] & 0xf7de) >> 1);
                }
            }
        }
    }

    dfont(old_font);
}

void render_pfg_all2one(pfg_all2one_t const *paths, camera_t const *c)
{
    for(int row = 0; row < paths->map->height; row++)
    for(int col = 0; col < paths->map->width; col++) {
        struct tile *tile = map_tile(paths->map, col, row);
        if(!tile || tile->solid) continue;

        fpoint_t fp = point_i2f_center((ipoint_t){ col, row });
        ipoint_t p = camera_map2screen(c, fp);

        int dir = paths->direction[row * paths->map->width + col];
        if(dir == -1) {
            drect(p.x-1, p.y-1, p.x+1, p.y+1, C_RGB(31, 0, 31));
        }
        else {
            ipoint_t v = point_f2i(fdir(dir));
            int x2 = p.x + 8*v.x;
            int y2 = p.y + 8*v.y;
            int dx = 3*v.x, dy = 3*v.y;

            dline(p.x, p.y, x2, y2, C_RGB(31, 0, 31));
            dline(x2, y2, x2-dx-dy, y2-dy-dx, C_RGB(31, 0, 31));
            dline(x2, y2, x2-dx+dy, y2-dy+dx, C_RGB(31, 0, 31));
        }
    }
}