#include "context.h"

#define CHR_W 6
#define CHR_H 13

namespace ui
{
    Context::Context(SDL_Window *window)
    {
        this->win = window;
        this->ren = SDL_CreateRenderer(this->win, NULL);
        this->fontTex = LoadTexture("font.png");

        this->offsetX = this->offsetY = 0;
    }

    Context::~Context()
    {
        SDL_DestroyTexture(this->fontTex);
        SDL_DestroyRenderer(this->ren);
    }

    SDL_Texture *Context::CreateTexture(int width, int height)
    {
        SDL_Texture *texture = SDL_CreateTexture(this->ren, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STREAMING, width, height);
        SDL_SetTextureScaleMode(texture, SDL_SCALEMODE_NEAREST);
        SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
        return texture;
    }

    SDL_Texture *Context::LoadTexture(const char* filename)
    {
        SDL_Surface *bmp_surface = SDL_LoadPNG(filename);
        SDL_Texture *texture = SDL_CreateTextureFromSurface(this->ren, bmp_surface);
        SDL_DestroySurface(bmp_surface);
        SDL_SetTextureScaleMode(texture, SDL_SCALEMODE_NEAREST);
        SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
        return texture;
    }

    void Context::SetOffset(int x, int y)
    {
        this->offsetX = x;
        this->offsetY = y;
    }

    void Context::IncOffset(int x, int y)
    {
        this->offsetX += x;
        this->offsetY += y;
    }

    int Context::GetOffsetX()
    {
        return this->offsetX;
    }

    int Context::GetOffsetY()
    {
        return this->offsetY;
    }

    void Context::PushOffset()
    {
        this->offsetStack.push({this->offsetX, this->offsetY});
    }

    void Context::PopOffset()
    {
        this->offsetX = this->offsetStack.top().first;
        this->offsetY = this->offsetStack.top().second;
        this->offsetStack.pop();
    }

    void Context::ClearOffsetStack()
    {
        this->offsetStack = std::stack<std::pair<int, int>>();
    }

    bool Context::IsMouseInside(int x, int y, int w, int h)
    {
        float tmpf_x, tmpf_y;
        SDL_GetMouseState(&tmpf_x, &tmpf_y);

        const int tmp_x = int(tmpf_x) + this->offsetX;
        const int tmp_y = int(tmpf_y) + this->offsetY;

        return ( (tmp_x >= x) && (tmp_x < x+w) && (tmp_y >= y) && (tmp_y < y+h) );
    }

    void Context::Clear(uint32_t color)
    {
        SDL_SetRenderDrawColor(ren, (color>>16)&0xff, (color>>8)&0xff, color&0xff, (color>>24)&0xff);
        SDL_RenderClear(ren);
    }

    void Context::DrawRect(int x, int y, int w, int h, uint32_t color)
    {
        SDL_FRect rect {float(this->offsetX+x), float(this->offsetY+y), float(w), float(h)};
        SDL_SetRenderDrawColor(this->ren, (color>>16)&0xff, (color>>8)&0xff, color&0xff, (color>>24)&0xff);
        SDL_RenderRect(this->ren, &rect);
    }

    void Context::FillRect(int x, int y, int w, int h, uint32_t color)
    {
        SDL_FRect rect {float(this->offsetX+x), float(this->offsetY+y), float(w), float(h)};
        SDL_SetRenderDrawColor(this->ren, (color>>16)&0xff, (color>>8)&0xff, color&0xff, (color>>24)&0xff);
        SDL_RenderFillRect(this->ren, &rect);
    }

    void Context::DrawLine(int x1, int y1, int x2, int y2, uint32_t color)
    {
        SDL_SetRenderDrawColor(this->ren, (color>>16)&0xff, (color>>8)&0xff, color&0xff, (color>>24)&0xff);
        SDL_RenderLine(this->ren, float(this->offsetX+x1), float(this->offsetY+y1), float(this->offsetX+x2), float(this->offsetY+y2));
    }

    void Context::DrawChar(int x, int y, char chr, uint32_t color=0xffffffff)
    {
        if (color != 255) SDL_SetRenderDrawColor(this->ren, (color>>16)&0xff, (color>>8)&0xff, color&0xff, (color>>24)&0xff);
        if (chr==32) return;
        if (chr<32 || chr>127) chr = '.';
        SDL_FRect src {float((chr-32)&0xf)*CHR_W, float((chr-32)>>4)*CHR_H, float(CHR_W), float(CHR_H)};
        SDL_FRect dst {float(this->offsetX+x), float(this->offsetY+y), float(CHR_W), float(CHR_H)};
        SDL_RenderTexture(ren, this->fontTex, &src, &dst);
    }

    void Context::DrawText(int x, int y, const char *text, uint32_t color)
    {
        SDL_SetTextureColorMod(this->fontTex, (color>>16)&0xff, (color>>8)&0xff, color&0xff);
        for (int i=0; i<(int)strlen(text);++i) if (text[i]!=32) DrawChar(x+i*CHR_W, y, text[i]);
    }

    void Context::Present()
    {
        SDL_RenderPresent(this->ren);
    }
}