/********************************************************************
 * This file includes functions that are used to annotate device-level
 * information, in particular the routing resource graph
 *******************************************************************/
/* Headers from vtrutil library */
#include "vtr_time.h"
#include "vtr_assert.h"
#include "vtr_log.h"

/* Headers from openfpgautil library */
#include "openfpga_side_manager.h"

/* Headers from vpr library */
#include "rr_graph_obj_util.h"

#include "annotate_rr_graph.h"

/* begin namespace openfpga */
namespace openfpga {

constexpr char* VPR_DELAYLESS_SWITCH_NAME = "__vpr_delayless_switch__";

/* Build a RRChan Object with the given channel type and coorindators */
static 
RRChan build_one_rr_chan(const DeviceContext& vpr_device_ctx,
                         const t_rr_type& chan_type, 
                         vtr::Point<size_t>& chan_coord) {
  std::vector<RRNodeId> chan_rr_nodes;

  /* Create a rr_chan object and check if it is unique in the graph */
  RRChan rr_chan;
  /* Fill the information */
  rr_chan.set_type(chan_type); 

  /* Collect rr_nodes for this channel */
  chan_rr_nodes = find_rr_graph_chan_nodes(vpr_device_ctx.rr_graph,
                                           chan_coord.x(), chan_coord.y(),
                                           chan_type);
  /* Fill the rr_chan */  
  for (const RRNodeId& chan_rr_node : chan_rr_nodes) {
    rr_chan.add_node(vpr_device_ctx.rr_graph, chan_rr_node, 
                     vpr_device_ctx.rr_graph.node_segment(chan_rr_node));
  }

  return rr_chan;
}

/* Build a General Switch Block (GSB) 
 * which includes:
 * [I] A Switch Box subckt consists of following ports:
 * 1. Channel Y [x][y] inputs 
 * 2. Channel X [x+1][y] inputs
 * 3. Channel Y [x][y-1] outputs
 * 4. Channel X [x][y] outputs
 * 5. Grid[x][y+1] Right side outputs pins
 * 6. Grid[x+1][y+1] Left side output pins
 * 7. Grid[x+1][y+1] Bottom side output pins
 * 8. Grid[x+1][y] Top side output pins
 * 9. Grid[x+1][y] Left side output pins
 * 10. Grid[x][y] Right side output pins
 * 11. Grid[x][y] Top side output pins
 * 12. Grid[x][y+1] Bottom side output pins
 *
 *    --------------          --------------
 *    |            |   CBY    |            |
 *    |    Grid    |  ChanY   |    Grid    |
 *    |  [x][y+1]  | [x][y+1] | [x+1][y+1] |
 *    |            |          |            |
 *    --------------          --------------
 *                  ----------
 *     ChanX & CBX  | Switch |     ChanX 
 *       [x][y]     |   Box  |    [x+1][y]
 *                  | [x][y] |
 *                  ----------
 *    --------------          --------------
 *    |            |          |            |
 *    |    Grid    |  ChanY   |    Grid    |
 *    |   [x][y]   |  [x][y]  |  [x+1][y]  |
 *    |            |          |            |
 *    --------------          --------------
 * For channels chanY with INC_DIRECTION on the top side, they should be marked as outputs
 * For channels chanY with DEC_DIRECTION on the top side, they should be marked as inputs
 * For channels chanY with INC_DIRECTION on the bottom side, they should be marked as inputs
 * For channels chanY with DEC_DIRECTION on the bottom side, they should be marked as outputs
 * For channels chanX with INC_DIRECTION on the left side, they should be marked as inputs
 * For channels chanX with DEC_DIRECTION on the left side, they should be marked as outputs
 * For channels chanX with INC_DIRECTION on the right side, they should be marked as outputs
 * For channels chanX with DEC_DIRECTION on the right side, they should be marked as inputs
 *
 * [II] A X-direction Connection Block [x][y]
 * The connection block shares the same routing channel[x][y] with the Switch Block
 * We just need to fill the ipin nodes at TOP and BOTTOM sides 
 * as well as properly fill the ipin_grid_side information
 * [III] A Y-direction Connection Block [x][y+1]
 * The connection block shares the same routing channel[x][y+1] with the Switch Block
 * We just need to fill the ipin nodes at LEFT and RIGHT sides 
 * as well as properly fill the ipin_grid_side information
 */
static 
RRGSB build_rr_gsb(const DeviceContext& vpr_device_ctx, 
                   const vtr::Point<size_t>& gsb_range,
                   const vtr::Point<size_t>& gsb_coord) {
  /* Create an object to return */
  RRGSB rr_gsb;

  VTR_ASSERT(gsb_coord.x() <= gsb_range.x()); 
  VTR_ASSERT(gsb_coord.y() <= gsb_range.y()); 

  /* Coordinator initialization */
  rr_gsb.set_coordinate(gsb_coord.x(), gsb_coord.y());

  /* Basic information*/
  rr_gsb.init_num_sides(4); /* Fixed number of sides */

  /* Find all rr_nodes of channels */
  /* Side: TOP => 0, RIGHT => 1, BOTTOM => 2, LEFT => 3 */
  for (size_t side = 0; side < rr_gsb.get_num_sides(); ++side) {
    /* Local variables inside this for loop */
    SideManager side_manager(side);
    vtr::Point<size_t> coordinate = rr_gsb.get_side_block_coordinate(side_manager.get_side());
    RRChan rr_chan;
    std::vector<std::vector<RRNodeId>> temp_opin_rr_nodes(2);
    enum e_side opin_grid_side[2] = {NUM_SIDES, NUM_SIDES};
    enum PORTS chan_dir_to_port_dir_mapping[2] = {OUT_PORT, IN_PORT}; /* 0: INC_DIRECTION => ?; 1: DEC_DIRECTION => ? */

    switch (side) {
    case TOP: /* TOP = 0 */
      /* For the border, we should take special care */
      if (gsb_coord.y() == gsb_range.y()) {
        rr_gsb.clear_one_side(side_manager.get_side());
        break;
      }
      /* Routing channels*/
      /* Side: TOP => 0, RIGHT => 1, BOTTOM => 2, LEFT => 3 */
      /* Create a rr_chan object and check if it is unique in the graph */
      rr_chan = build_one_rr_chan(vpr_device_ctx, CHANY, coordinate);
      chan_dir_to_port_dir_mapping[0] = OUT_PORT; /* INC_DIRECTION => OUT_PORT */
      chan_dir_to_port_dir_mapping[1] =  IN_PORT; /* DEC_DIRECTION => IN_PORT */

      /* Build the Switch block: opin and opin_grid_side */
      /* Assign grid side of OPIN */
      /* Grid[x][y+1] RIGHT side outputs pins */
      opin_grid_side[0] = RIGHT;
      /* Grid[x+1][y+1] left side outputs pins */
      opin_grid_side[1] = LEFT; 
      /* Include Grid[x][y+1] RIGHT side outputs pins */
      temp_opin_rr_nodes[0] = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                       gsb_coord.x(), gsb_coord.y() + 1, OPIN, opin_grid_side[0]);
      /* Include Grid[x+1][y+1] Left side output pins */
      temp_opin_rr_nodes[1] = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                       gsb_coord.x() + 1, gsb_coord.y() + 1, OPIN, opin_grid_side[1]);

      break;
    case RIGHT: /* RIGHT = 1 */
      /* For the border, we should take special care */
      if (gsb_coord.x() == gsb_range.x()) {
        rr_gsb.clear_one_side(side_manager.get_side());
        break;
      }
      /* Routing channels*/
      /* Side: TOP => 0, RIGHT => 1, BOTTOM => 2, LEFT => 3 */
      /* Collect rr_nodes for Tracks for top: chany[x][y+1] */
      /* Create a rr_chan object and check if it is unique in the graph */
      rr_chan = build_one_rr_chan(vpr_device_ctx, CHANX, coordinate);
      chan_dir_to_port_dir_mapping[0] = OUT_PORT; /* INC_DIRECTION => OUT_PORT */
      chan_dir_to_port_dir_mapping[1] =  IN_PORT; /* DEC_DIRECTION => IN_PORT */

      /* Build the Switch block: opin and opin_grid_side */
      /* Assign grid side of OPIN */
      /* Grid[x+1][y+1] BOTTOM side outputs pins */
      opin_grid_side[0] = BOTTOM;
      /* Grid[x+1][y] TOP side outputs pins */
      opin_grid_side[1] = TOP;

      /* include Grid[x+1][y+1] Bottom side output pins */
      temp_opin_rr_nodes[0] = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                       gsb_coord.x() + 1, gsb_coord.y() + 1, OPIN, opin_grid_side[0]);
      /* include Grid[x+1][y] Top side output pins */
      temp_opin_rr_nodes[1] = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                       gsb_coord.x() + 1, gsb_coord.y(), OPIN, opin_grid_side[1]);
      break;
    case BOTTOM: /* BOTTOM = 2*/
      /* For the border, we should take special care */
      if (gsb_coord.y() == 0) {
        rr_gsb.clear_one_side(side_manager.get_side());
        break;
      }
      /* Routing channels*/
      /* Side: TOP => 0, RIGHT => 1, BOTTOM => 2, LEFT => 3 */
      /* Collect rr_nodes for Tracks for bottom: chany[x][y] */
      /* Create a rr_chan object and check if it is unique in the graph */
      rr_chan = build_one_rr_chan(vpr_device_ctx, CHANY, coordinate);
      chan_dir_to_port_dir_mapping[0] =  IN_PORT; /* INC_DIRECTION => IN_PORT */
      chan_dir_to_port_dir_mapping[1] = OUT_PORT; /* DEC_DIRECTION => OUT_PORT */

      /* Build the Switch block: opin and opin_grid_side */
      /* Assign grid side of OPIN */
      /* Grid[x+1][y] LEFT side outputs pins */
      opin_grid_side[0] = LEFT;
      /* Grid[x][y] RIGHT side outputs pins */
      opin_grid_side[1] = RIGHT;
      /* include Grid[x+1][y] Left side output pins */
      temp_opin_rr_nodes[0] = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                       gsb_coord.x() + 1, gsb_coord.y(), OPIN, opin_grid_side[0]);
      /* include Grid[x][y] Right side output pins */
      temp_opin_rr_nodes[1] = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                       gsb_coord.x(), gsb_coord.y(), OPIN, opin_grid_side[1]);
      break;
    case LEFT: /* LEFT = 3 */
      /* For the border, we should take special care */
      if (gsb_coord.x() == 0) {
        rr_gsb.clear_one_side(side_manager.get_side());
        break;
      }
      /* Routing channels*/
      /* Side: TOP => 0, RIGHT => 1, BOTTOM => 2, LEFT => 3 */
      /* Collect rr_nodes for Tracks for left: chanx[x][y] */
      /* Create a rr_chan object and check if it is unique in the graph */
      rr_chan = build_one_rr_chan(vpr_device_ctx, CHANX, coordinate);
      chan_dir_to_port_dir_mapping[0] =  IN_PORT; /* INC_DIRECTION => IN_PORT */
      chan_dir_to_port_dir_mapping[1] = OUT_PORT; /* DEC_DIRECTION => OUT_PORT */

      /* Build the Switch block: opin and opin_grid_side */
      /* Grid[x][y+1] BOTTOM side outputs pins */
      opin_grid_side[0] = BOTTOM;
      /* Grid[x][y] TOP side outputs pins */
      opin_grid_side[1] = TOP;
      /* include Grid[x][y+1] Bottom side outputs pins */
      temp_opin_rr_nodes[0] = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                       gsb_coord.x(), gsb_coord.y() + 1, OPIN, opin_grid_side[0]);
      /* include Grid[x][y] Top side output pins */
      temp_opin_rr_nodes[1] = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                       gsb_coord.x(), gsb_coord.y(), OPIN, opin_grid_side[1]);
      break;
    default:
      VTR_LOG_ERROR("Invalid side index!\n");
      exit(1);
    }

    /* Organize a vector of port direction */
    if (0 < rr_chan.get_chan_width()) {
      std::vector<enum PORTS> rr_chan_dir;
      rr_chan_dir.resize(rr_chan.get_chan_width());
      for (size_t itrack = 0; itrack < rr_chan.get_chan_width(); ++itrack) {
        /* Identify the directionality, record it in rr_node_direction */
        if (INC_DIRECTION == vpr_device_ctx.rr_graph.node_direction(rr_chan.get_node(itrack))) {
          rr_chan_dir[itrack] = chan_dir_to_port_dir_mapping[0];
        } else {
          VTR_ASSERT(DEC_DIRECTION == vpr_device_ctx.rr_graph.node_direction(rr_chan.get_node(itrack)));
          rr_chan_dir[itrack] = chan_dir_to_port_dir_mapping[1];
        }
      }
      /* Fill chan_rr_nodes */
      rr_gsb.add_chan_node(side_manager.get_side(), rr_chan, rr_chan_dir);
    }

    /* Fill opin_rr_nodes */
    /* Copy from temp_opin_rr_node to opin_rr_node */
    for (const RRNodeId& inode : temp_opin_rr_nodes[0]) {
      /* Grid[x+1][y+1] Bottom side outputs pins */
      rr_gsb.add_opin_node(inode, side_manager.get_side());
    }
    for (const RRNodeId& inode : temp_opin_rr_nodes[1]) {
      /* Grid[x+1][y] TOP side outputs pins */
      rr_gsb.add_opin_node(inode, side_manager.get_side());
    }

    /* Clean ipin_rr_nodes */
    /* We do not have any IPIN for a Switch Block */
    rr_gsb.clear_ipin_nodes(side_manager.get_side());

    /* Clear the temp data */
    temp_opin_rr_nodes[0].clear();
    temp_opin_rr_nodes[1].clear();
    opin_grid_side[0] = NUM_SIDES;
    opin_grid_side[1] = NUM_SIDES;
  }

  /* Side: TOP => 0, RIGHT => 1, BOTTOM => 2, LEFT => 3 */
  for (size_t side = 0; side < rr_gsb.get_num_sides(); ++side) {
    /* Local variables inside this for loop */
    SideManager side_manager(side);
    size_t ix; 
    size_t iy; 
    enum e_side chan_side;
    std::vector<RRNodeId> temp_ipin_rr_nodes;
    enum e_side ipin_rr_node_grid_side;
   
    switch (side) {
    case TOP: /* TOP = 0 */
      /* For the bording, we should take special care */
      /* Check if left side chan width is 0 or not */
      chan_side = LEFT;
      /* Build the connection block: ipin and ipin_grid_side */
      /* BOTTOM side INPUT Pins of Grid[x][y+1] */
      ix = rr_gsb.get_sb_x(); 
      iy = rr_gsb.get_sb_y() + 1; 
      ipin_rr_node_grid_side = BOTTOM; 
      break;
    case RIGHT: /* RIGHT = 1 */
      /* For the bording, we should take special care */
      /* Check if TOP side chan width is 0 or not */
      chan_side = TOP;
      /* Build the connection block: ipin and ipin_grid_side */
      /* LEFT side INPUT Pins of Grid[x+1][y+1] */
      ix = rr_gsb.get_sb_x() + 1; 
      iy = rr_gsb.get_sb_y() + 1; 
      ipin_rr_node_grid_side = LEFT; 
      break;
    case BOTTOM: /* BOTTOM = 2*/
      /* For the bording, we should take special care */
      /* Check if left side chan width is 0 or not */
      chan_side = LEFT;
      /* Build the connection block: ipin and ipin_grid_side */
      /* TOP side INPUT Pins of Grid[x][y] */
      ix = rr_gsb.get_sb_x(); 
      iy = rr_gsb.get_sb_y(); 
      ipin_rr_node_grid_side = TOP; 
      break;
    case LEFT: /* LEFT = 3 */
      /* For the bording, we should take special care */
      /* Check if left side chan width is 0 or not */
      chan_side = TOP;
      /* Build the connection block: ipin and ipin_grid_side */
      /* RIGHT side INPUT Pins of Grid[x][y+1] */
      ix = rr_gsb.get_sb_x(); 
      iy = rr_gsb.get_sb_y() + 1; 
      ipin_rr_node_grid_side = RIGHT; 
      break;
    default:
      VTR_LOG_ERROR("Invalid side index!\n");
      exit(1);
    }
    
    /* If there is no channel at this side, we skip ipin_node annotation */
    if (0 == rr_gsb.get_chan_width(chan_side)) {
      continue;
    }
    /* Collect IPIN rr_nodes*/ 
    temp_ipin_rr_nodes = find_rr_graph_grid_nodes(vpr_device_ctx.rr_graph, vpr_device_ctx.grid, 
                                                  ix, iy, IPIN, ipin_rr_node_grid_side);
    /* Fill the ipin nodes of RRGSB */ 
    for (const RRNodeId& inode : temp_ipin_rr_nodes) {
      rr_gsb.add_ipin_node(inode, side_manager.get_side());
    }
    /* Clear the temp data */
    temp_ipin_rr_nodes.clear();
  }

  return rr_gsb;
}

/********************************************************************
 * Build the annotation for the routing resource graph
 * by collecting the nodes to the General Switch Block context
 *******************************************************************/
void annotate_device_rr_gsb(const DeviceContext& vpr_device_ctx, 
                            DeviceRRGSB& device_rr_gsb,
                            const bool& verbose_output) {

  vtr::ScopedStartFinishTimer timer("Build General Switch Block(GSB) annotation on top of routing resource graph");

  /* Note that the GSB array is smaller than the grids by 1 column and 1 row!!! */
  vtr::Point<size_t> gsb_range(vpr_device_ctx.grid.width() - 1, vpr_device_ctx.grid.height() - 1);
  device_rr_gsb.reserve(gsb_range);

  VTR_LOGV(verbose_output, 
           "Start annotation GSB up to [%lu][%lu]\n",
           gsb_range.x(), gsb_range.y());

  size_t gsb_cnt = 0;
  /* For each switch block, determine the size of array */
  for (size_t ix = 0; ix < gsb_range.x(); ++ix) {
    for (size_t iy = 0; iy < gsb_range.y(); ++iy) {
      /* Here we give the builder the fringe coordinates so that it can handle the GSBs at the borderside correctly */
      const RRGSB& rr_gsb = build_rr_gsb(vpr_device_ctx, 
                                         vtr::Point<size_t>(vpr_device_ctx.grid.width() - 2, vpr_device_ctx.grid.height() - 2), 
                                         vtr::Point<size_t>(ix, iy));
      /* TODO: sort drive_rr_nodes should be done when building the tileable rr_graph */
      //sort_rr_gsb_drive_rr_nodes(rr_gsb);
 
      /* Add to device_rr_gsb */
      vtr::Point<size_t> gsb_coordinate = rr_gsb.get_sb_coordinate();
      device_rr_gsb.add_rr_gsb(gsb_coordinate, rr_gsb);
      gsb_cnt++; /* Update counter */
      /* Print info */
      VTR_LOG("[%lu%] Backannotated GSB[%lu][%lu]\r",
              100 * gsb_cnt / (gsb_range.x() * gsb_range.y()), 
              ix, iy);
    }
  }
  /* Report number of unique mirrors */
  VTR_LOG("Backannotated %d General Switch Blocks (GSBs).\n",
          gsb_range.x() * gsb_range.y());
}

/********************************************************************
 * Build the link between rr_graph switches to their physical circuit models 
 * The binding is done based on the name of rr_switches defined in the
 * OpenFPGA arch XML
 *******************************************************************/
static 
void annotate_rr_switch_circuit_models(const DeviceContext& vpr_device_ctx, 
                                       const Arch& openfpga_arch,
                                       VprDeviceAnnotation& vpr_device_annotation,
                                       const bool& verbose_output) {
  size_t count = 0;

  for (size_t iswitch = 0; iswitch < vpr_device_ctx.rr_switch_inf.size(); iswitch++) {
    std::string switch_name(vpr_device_ctx.rr_switch_inf[iswitch].name); 
    /* Skip the delayless switch, which is only used by the edges between
     * - SOURCE and OPIN
     * - IPIN and SINK  
     */
    if (switch_name == std::string(VPR_DELAYLESS_SWITCH_NAME)) {
      continue;
    }

    CircuitModelId circuit_model = CircuitModelId::INVALID();
    /* The name-to-circuit mapping is stored in either cb_switch-to-circuit or sb_switch-to-circuit,
     * Try to find one and update the device annotation
     */ 
    if (0 < openfpga_arch.cb_switch2circuit.count(switch_name)) {
      circuit_model = openfpga_arch.cb_switch2circuit.at(switch_name); 
    }
    if (0 < openfpga_arch.sb_switch2circuit.count(switch_name)) {
      if (CircuitModelId::INVALID() != circuit_model) {
        VTR_LOG_WARN("Found a connection block and a switch block switch share the same name '%s' and binded to different circuit models '%s' and '%s'!\nWill use the switch block switch binding!\n",
                     switch_name.c_str(),
                     openfpga_arch.circuit_lib.model_name(circuit_model).c_str(),
                     openfpga_arch.circuit_lib.model_name(openfpga_arch.sb_switch2circuit.at(switch_name)).c_str());
      }
      circuit_model = openfpga_arch.sb_switch2circuit.at(switch_name); 
    }

    /* Cannot find a circuit model, error out! */
    if (CircuitModelId::INVALID() == circuit_model) {
      VTR_LOG_ERROR("Fail to find a circuit model for a routing resource graph switch '%s'!\nPlease check your OpenFPGA architecture XML!\n",
                    switch_name.c_str());
      exit(1);
    }
  
    /* Now update the device annotation */
    vpr_device_annotation.add_rr_switch_circuit_model(RRSwitchId(iswitch), circuit_model);
    VTR_LOGV(verbose_output, 
             "Binded a routing resource graph switch '%s' to circuit model '%s'\n",
             switch_name.c_str(),
             openfpga_arch.circuit_lib.model_name(circuit_model).c_str());
    count++;
  }
  
  VTR_LOG("Binded %lu routing resource graph switches to circuit models\n",
          count);
}

/********************************************************************
 * Build the link between rr_graph switches and segments to their
 * physical circuit models 
 *******************************************************************/
void annotate_rr_graph_circuit_models(const DeviceContext& vpr_device_ctx, 
                                      const Arch& openfpga_arch,
                                      VprDeviceAnnotation& vpr_device_annotation,
                                      const bool& verbose_output) {
  /* Iterate over each rr_switch in the device context and bind with names */
  annotate_rr_switch_circuit_models(vpr_device_ctx, openfpga_arch, vpr_device_annotation, verbose_output);
}

} /* end namespace openfpga */