#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <Eina.h>
#include <Ector.h>
#include <software/Ector_Software.h>

#include "ector_private.h"
#include "ector_software_private.h"

#include "draw.h"

static void
_blend_color_argb(int count, const SW_FT_Span *spans, void *user_data)
{
   RGBA_Comp_Func_Solid comp_func;
   Span_Data *data = (Span_Data *)(user_data);
   uint32_t color, *buffer, *target;
   const int pix_stride = data->raster_buffer->stride / 4;

   // multiply the color with mul_col if any
   color = DRAW_MUL4_SYM(data->color, data->mul_col);
   comp_func = efl_draw_func_solid_span_get(data->op, color);

   // move to the offset location
   buffer = data->raster_buffer->pixels.u32 + ((pix_stride * data->offy) + data->offx);

   while (count--)
     {
        target = buffer + ((pix_stride * spans->y) + spans->x);
        comp_func(target, spans->len, color, spans->coverage);
        ++spans;
     }
}

#define BLEND_GRADIENT_BUFFER_SIZE 2048

typedef void (*src_fetch) (unsigned int *buffer, Span_Data *data, int y, int x, int length);

static void
_blend_gradient(int count, const SW_FT_Span *spans, void *user_data)
{
   RGBA_Comp_Func comp_func;
   Span_Data *data = (Span_Data *)(user_data);
   src_fetch fetchfunc = NULL;
   unsigned int buffer[BLEND_GRADIENT_BUFFER_SIZE], *target, *destbuffer;
   int length, l;
   const int pix_stride = data->raster_buffer->stride / 4;

   //@TODO, Get the proper composition function using ,color, ECTOR_OP etc.
   if (data->type == LinearGradient) fetchfunc = &fetch_linear_gradient;
   if (data->type == RadialGradient) fetchfunc = &fetch_radial_gradient;

   if (!fetchfunc)
     return;

   comp_func = efl_draw_func_span_get(data->op, data->mul_col, data->gradient->alpha);

   // move to the offset location
   destbuffer = data->raster_buffer->pixels.u32 + ((pix_stride * data->offy) + data->offx);

   while (count--)
     {
        target = destbuffer + ((pix_stride * spans->y) + spans->x);
        length = spans->len;
        while (length)
          {
             l = MIN(length, BLEND_GRADIENT_BUFFER_SIZE);
             fetchfunc(buffer, data, spans->y, spans->x, l);
             comp_func(target, buffer, l, data->mul_col, spans->coverage);
             target += l;
             length -= l;
          }
        ++spans;
     }
}

static void
_blend_image_argb(int count, const SW_FT_Span *spans, void *user_data)
{
   Span_Data *data = user_data;
   RGBA_Comp_Func comp_func;
   uint32_t *buffer, *target;
   uint8_t *src8;
   unsigned int l, length, sy = 0;
   const int pix_stride = data->raster_buffer->stride / 4;

   /* FIXME:
    * optimize eo call
    * implement image scaling
    * tile and repeat image properly
    */

   comp_func = efl_draw_func_span_get(data->op, data->mul_col, EINA_TRUE);
   buffer = data->raster_buffer->pixels.u32 + ((pix_stride * data->offy) + data->offx);

   while (count--)
     {
        target = buffer + ((pix_stride * spans->y) + spans->x);
        length = spans->len;
        while (length)
          {
             l = MIN(length, data->buffer->generic->w);
             src8 = ector_buffer_span_get(data->buffer->generic->eo, 0, sy, l, EFL_GFX_COLORSPACE_ARGB8888, NULL);
             comp_func(target, (uint32_t *) src8, l, data->mul_col, spans->coverage);
             ector_buffer_span_free(data->buffer->generic->eo, src8);
             target += l;
             length -= l;
          }
        ++spans;
        ++sy;
        if (sy >= data->buffer->generic->h)
          sy = 0;
     }
}

/*!
    \internal
    spans must be sorted on y
*/
static const
SW_FT_Span *_intersect_spans_rect(const Eina_Rectangle *clip,
                                  const SW_FT_Span *spans,
                                  const SW_FT_Span *end,
                                  SW_FT_Span **out_spans,
                                  int available)
{
   SW_FT_Span *out = *out_spans;
   short minx, miny, maxx, maxy;
   minx = clip->x;
   miny = clip->y;
   maxx = minx + clip->w - 1;
   maxy = miny + clip->h - 1;

   while (available && spans < end )
     {
        if (spans->y > maxy)
          {
             spans = end;// update spans so that we can breakout
             break;
          }
        if (spans->y < miny
            || spans->x > maxx
            || spans->x + spans->len <= minx)
          {
             ++spans;
             continue;
          }
        if (spans->x < minx)
          {
             out->len = MIN(spans->len - (minx - spans->x), maxx - minx + 1);
             out->x = minx;
          }
        else
          {
             out->x = spans->x;
             out->len = MIN(spans->len, (maxx - spans->x + 1));
          }
        if (out->len != 0)
          {
             out->y = spans->y;
             out->coverage = spans->coverage;
             ++out;
          }
        ++spans;
        --available;
     }

   *out_spans = out;
   return spans;
}

static inline int
_div_255(int x) { return (x + (x>>8) + 0x80) >> 8; }

static const
SW_FT_Span *_intersect_spans_region(const Shape_Rle_Data *clip,
                                    int *currentClip,
                                    const SW_FT_Span *spans,
                                    const SW_FT_Span *end,
                                    SW_FT_Span **out_spans,
                                    int available)
{
   SW_FT_Span *out = *out_spans;
   int sx1, sx2, cx1, cx2, x, len;

   const SW_FT_Span *clipSpans = clip->spans + *currentClip;
   const SW_FT_Span *clipEnd = clip->spans + clip->size;

   while (available && spans < end )
     {
        if (clipSpans >= clipEnd)
          {
             spans = end;
             break;
          }
        if (clipSpans->y > spans->y)
          {
             ++spans;
             continue;
          }
        if (spans->y != clipSpans->y)
          {
             ++clipSpans;
             continue;
          }
        //assert(spans->y == clipSpans->y);
        sx1 = spans->x;
        sx2 = sx1 + spans->len;
        cx1 = clipSpans->x;
        cx2 = cx1 + clipSpans->len;

        if (cx1 < sx1 && cx2 < sx1)
          {
             ++clipSpans;
             continue;
          }
        else if (sx1 < cx1 && sx2 < cx1)
          {
             ++spans;
             continue;
          }
        x = MAX(sx1, cx1);
        len = MIN(sx2, cx2) - x;
        if (len)
          {
             out->x = MAX(sx1, cx1);
             out->len = MIN(sx2, cx2) - out->x;
             out->y = spans->y;
             out->coverage = _div_255(spans->coverage * clipSpans->coverage);
             ++out;
             --available;
          }
        if (sx2 < cx2)
          {
             ++spans;
          }
        else
          {
             ++clipSpans;
          }
     }

   *out_spans = out;
   *currentClip = clipSpans - clip->spans;
   return spans;
}

static void
_span_fill_clipRect(int span_count, const SW_FT_Span *spans, void *user_data)
{
   const int NSPANS = 256;
   int clip_count, i;
   SW_FT_Span cspans[NSPANS];
   Span_Data *fill_data = (Span_Data *) user_data;
   Clip_Data clip = fill_data->clip;
   SW_FT_Span *clipped;
   Eina_Rectangle *rect;
   Eina_Rectangle tmp_rect;


   clip_count = eina_array_count(clip.clips);
   for (i = 0; i < clip_count; i++)
     {
        rect = (Eina_Rectangle *)eina_array_data_get(clip.clips, i);

        // invert transform the offset
        tmp_rect.x = rect->x - fill_data->offx;
        tmp_rect.y = rect->y - fill_data->offy;
        tmp_rect.w = rect->w;
        tmp_rect.h = rect->h;
        const SW_FT_Span *end = spans + span_count;

        while (spans < end)
          {
             clipped = cspans;
             spans = _intersect_spans_rect(&tmp_rect, spans, end, &clipped, NSPANS);
             if (clipped - cspans)
               fill_data->unclipped_blend(clipped - cspans, cspans, fill_data);
          }
     }
}

static void
_span_fill_clipPath(int span_count, const SW_FT_Span *spans, void *user_data)
{
   const int NSPANS = 256;
   int current_clip = 0;
   SW_FT_Span cspans[NSPANS];
   Span_Data *fill_data = (Span_Data *) user_data;
   Clip_Data clip = fill_data->clip;
   SW_FT_Span *clipped;

   //TODO take clip path offset into account.
   const SW_FT_Span *end = spans + span_count;
   while (spans < end)
     {
        clipped = cspans;
        spans = _intersect_spans_region(clip.path, &current_clip, spans, end, &clipped, NSPANS);
        if (clipped - cspans)
          fill_data->unclipped_blend(clipped - cspans, cspans, fill_data);
     }
}

static void
_adjust_span_fill_methods(Span_Data *spdata)
{
   switch(spdata->type)
     {
        case None:
          spdata->unclipped_blend = 0;
          break;
        case Solid:
          spdata->unclipped_blend = &_blend_color_argb;
          break;
        case LinearGradient:
        case RadialGradient:
          spdata->unclipped_blend = &_blend_gradient;
          break;
        case Image:
          spdata->unclipped_blend = &_blend_image_argb;
          break;
     }

   // setup clipping
   if (!spdata->unclipped_blend)
     {
        spdata->blend = 0;
     }
   else if (!spdata->clip.enabled)
     {
        spdata->blend = spdata->unclipped_blend;
     }
   else if (spdata->clip.has_rect_clip)
     {
        spdata->blend = &_span_fill_clipRect;
     }
   else
     {
        spdata->blend = &_span_fill_clipPath;
     }
}

void ector_software_rasterizer_init(Software_Rasterizer *rasterizer)
{
   // initialize the rasterizer and stroker
   sw_ft_grays_raster.raster_new(&rasterizer->raster);

   SW_FT_Stroker_New(&rasterizer->stroker);
   SW_FT_Stroker_Set(rasterizer->stroker, 1<<6,SW_FT_STROKER_LINECAP_BUTT,SW_FT_STROKER_LINEJOIN_MITER,0);

   //initialize the span data.
   rasterizer->fill_data.clip.enabled = EINA_FALSE;
   rasterizer->fill_data.unclipped_blend = 0;
   rasterizer->fill_data.blend = 0;
   efl_draw_init();
   ector_software_gradient_init();
}

void ector_software_rasterizer_done(Software_Rasterizer *rasterizer)
{
   sw_ft_grays_raster.raster_done(rasterizer->raster);
   SW_FT_Stroker_Done(rasterizer->stroker);
}

void ector_software_rasterizer_stroke_set(Software_Rasterizer *rasterizer, double width,
                                          Efl_Gfx_Cap cap_style, Efl_Gfx_Join join_style,
                                          Eina_Matrix3 *m)
{
   SW_FT_Stroker_LineCap cap;
   SW_FT_Stroker_LineJoin join;
   int stroke_width;
   double scale_factor = 1.0;
   if (m)
     {
        // get the minimum scale factor from matrix
        scale_factor =  m->xx < m->yy ? m->xx : m->yy;
     }
   width = width * scale_factor;
   width = width/2.0; // as free type uses it as the radius of the
                      // pen not the diameter.
   // convert to freetype co-ordinate
   stroke_width = (int)(width * 64);

   switch (cap_style)
     {
        case EFL_GFX_CAP_SQUARE:
          cap = SW_FT_STROKER_LINECAP_SQUARE;
          break;
        case EFL_GFX_CAP_ROUND:
          cap = SW_FT_STROKER_LINECAP_ROUND;
          break;
        default:
          cap = SW_FT_STROKER_LINECAP_BUTT;
          break;
     }

   switch (join_style)
     {
        case EFL_GFX_JOIN_BEVEL:
          join = SW_FT_STROKER_LINEJOIN_BEVEL;
          break;
        case EFL_GFX_JOIN_ROUND:
          join = SW_FT_STROKER_LINEJOIN_ROUND;
          break;
        default:
          join = SW_FT_STROKER_LINEJOIN_MITER;
          break;
     }
   SW_FT_Stroker_Set(rasterizer->stroker, stroke_width, cap, join, 0);
}

static void
_rle_generation_cb( int count, const SW_FT_Span*  spans,void *user)
{
   Shape_Rle_Data *rle = (Shape_Rle_Data *) user;
   int newsize = rle->size + count;

   // allocate enough memory for new spans
   // alloc is required to prevent free and reallocation
   // when the rle needs to be regenerated because of attribute change.
   if (rle->alloc < newsize)
     {
        rle->spans = (SW_FT_Span *) realloc(rle->spans, newsize * sizeof(SW_FT_Span));
        rle->alloc = newsize;
     }

   // copy the new spans to the allocated memory
   SW_FT_Span *lastspan = (rle->spans + rle->size);
   memcpy(lastspan,spans, count * sizeof(SW_FT_Span));

   // update the size
   rle->size = newsize;
}

Shape_Rle_Data *
ector_software_rasterizer_generate_rle_data(Software_Rasterizer *rasterizer, SW_FT_Outline *outline)
{
   int i, rle_size;
   int l = 0, t = 0, r = 0, b = 0;
   Shape_Rle_Data *rle_data = (Shape_Rle_Data *) calloc(1, sizeof(Shape_Rle_Data));
   SW_FT_Raster_Params params;
   SW_FT_Span* span;

   params.flags = SW_FT_RASTER_FLAG_DIRECT | SW_FT_RASTER_FLAG_AA ;
   params.gray_spans = &_rle_generation_cb;
   params.user = rle_data;
   params.source = outline;

   sw_ft_grays_raster.raster_render(rasterizer->raster, &params);

   // update RLE bounding box.
   span = rle_data->spans;
   rle_size = rle_data->size;
   if (rle_size)
     {
        t = span[0].y;
        b = span[rle_size-1].y;
        for (i = 0; i < rle_size; i++)
          {
             if (span[i].x < l) l = span[i].x;
             if (span[i].x + span[i].len > r) r = span[i].x + span[i].len;
          }
        rle_data->bbox.x = l;
        rle_data->bbox.y = t;
        rle_data->bbox.w = r - l;
        rle_data->bbox.h = b - t + 1;
     }
   return rle_data;
}

Shape_Rle_Data *
ector_software_rasterizer_generate_stroke_rle_data(Software_Rasterizer *rasterizer, SW_FT_Outline *outline, Eina_Bool closePath)
{
   uint32_t points,contors;
   Shape_Rle_Data *rle_data;
   SW_FT_Outline strokeOutline = { 0, 0, NULL, NULL, NULL, 0 };

   SW_FT_Stroker_ParseOutline(rasterizer->stroker, outline, !closePath);
   SW_FT_Stroker_GetCounts(rasterizer->stroker,&points, &contors);

   strokeOutline.points = (SW_FT_Vector *) calloc(points, sizeof(SW_FT_Vector));
   strokeOutline.tags = (char *) calloc(points, sizeof(char));
   strokeOutline.contours = (short *) calloc(contors, sizeof(short));

   SW_FT_Stroker_Export(rasterizer->stroker, &strokeOutline);

   rle_data = ector_software_rasterizer_generate_rle_data(rasterizer, &strokeOutline);

   // cleanup the outline data.
   free(strokeOutline.points);
   free(strokeOutline.tags);
   free(strokeOutline.contours);

   return rle_data;
}

void ector_software_rasterizer_destroy_rle_data(Shape_Rle_Data *rle)
{
   if (rle)
     {
        if (rle->spans)
          free(rle->spans);
        free(rle);
     }
}

static
void _setup_span_fill_matrix(Software_Rasterizer *rasterizer)
{
   if (rasterizer->transform)
     {
        eina_matrix3_inverse(rasterizer->transform, &rasterizer->fill_data.inv);
     }
   else
     {
        eina_matrix3_identity(&rasterizer->fill_data.inv);
        eina_matrix3_identity(&rasterizer->fill_data.inv);
     }
}

void ector_software_rasterizer_transform_set(Software_Rasterizer *rasterizer, Eina_Matrix3 *t)
{
   rasterizer->transform = t;
}

void ector_software_rasterizer_clip_rect_set(Software_Rasterizer *rasterizer, Eina_Array *clips)
{
   if (clips)
     {
        rasterizer->fill_data.clip.clips = clips;
        rasterizer->fill_data.clip.has_rect_clip = EINA_TRUE;
        rasterizer->fill_data.clip.enabled = EINA_TRUE;
     }
   else
     {
        rasterizer->fill_data.clip.clips = NULL;
        rasterizer->fill_data.clip.has_rect_clip = EINA_FALSE;
        rasterizer->fill_data.clip.enabled = EINA_FALSE;
     }
}

void ector_software_rasterizer_clip_shape_set(Software_Rasterizer *rasterizer, Shape_Rle_Data *clip)
{
   rasterizer->fill_data.clip.path = clip;
   rasterizer->fill_data.clip.has_path_clip = EINA_TRUE;
   rasterizer->fill_data.clip.enabled = EINA_TRUE;
}

void ector_software_rasterizer_color_set(Software_Rasterizer *rasterizer, int r, int g, int b, int a)
{
   rasterizer->fill_data.color = DRAW_ARGB_JOIN(a, r, g, b);
   rasterizer->fill_data.type = Solid;
}

void ector_software_rasterizer_linear_gradient_set(Software_Rasterizer *rasterizer,
                                                   Ector_Renderer_Software_Gradient_Data *linear)
{
   rasterizer->fill_data.gradient = linear;
   rasterizer->fill_data.type = LinearGradient;
}

void ector_software_rasterizer_radial_gradient_set(Software_Rasterizer *rasterizer,
                                                   Ector_Renderer_Software_Gradient_Data *radial)
{
   rasterizer->fill_data.gradient = radial;
   rasterizer->fill_data.type = RadialGradient;
}

void ector_software_rasterizer_buffer_set(Software_Rasterizer *rasterizer,
                                          Ector_Software_Buffer *buffer)
{
   rasterizer->fill_data.buffer = efl_data_scope_get(buffer, ECTOR_SOFTWARE_BUFFER_BASE_MIXIN);
   rasterizer->fill_data.type = Image;
}

void ector_software_rasterizer_draw_rle_data(Software_Rasterizer *rasterizer,
                                             int x, int y, uint32_t mul_col,
                                             Efl_Gfx_Render_Op op, Shape_Rle_Data* rle)
{
   // check for NULL rle data
   if (!rle) return;

   rasterizer->fill_data.offx = x;
   rasterizer->fill_data.offy = y;
   rasterizer->fill_data.mul_col = mul_col;
   rasterizer->fill_data.op = op;

   _setup_span_fill_matrix(rasterizer);
   _adjust_span_fill_methods(&rasterizer->fill_data);

   if (rasterizer->fill_data.blend)
     rasterizer->fill_data.blend(rle->size, rle->spans, &rasterizer->fill_data);
}