#include <stdint.h>
#include <string.h>

#include "banking.h"
#include "ipc.h"
#include "pa2345.h"

#include "dist.h"

void child_phase0( dist_info_t *info, uint8_t id ) {
  close_redundant_pipes( info, id );
}

void child_phase1( dist_info_t *info, uint8_t id ) {
  pid_t child_pid = getpid();
  char buf[MAX_MESSAGE_LEN];
  uint8_t i;

  my_info_t me = {
    .id = id,
    .dist_info = info
  };

  int size = snprintf( buf, sizeof(buf), log_started_fmt, get_physical_time(),
                                                          id, child_pid, 
                                                          info->parent_pid, 
                                                          info->balances[ id ] );

  Message msg = {
    .s_header = {
      .s_magic = MESSAGE_MAGIC,
      .s_payload_len = size + 1,
      .s_type = STARTED,
      .s_local_time = get_physical_time()
    }
  };

  fputs( buf, info->events_log );
  fputs( buf, stdout );

  strncpy( msg.s_payload, buf, sizeof( msg.s_payload ) );
  send_multicast( &me, &msg );

  for( i = 1; i <= info->x; i++ ) {
    if( i == me.id )
      continue;

    if( !receive( &me, i, &msg ) ) {
      if( msg.s_header.s_type != STARTED ) {
        fprintf( stderr, "Message type INVALID (not STARTED)!\n" );
        break;
      }
    }
  }

  snprintf( buf, sizeof(buf), log_received_all_started_fmt, get_physical_time(), id ); 
  fputs( buf, info->events_log );
  fputs( buf, stdout );
}

void child_phase2( dist_info_t *info, uint8_t id, BalanceHistory *history ) {
  Message msg;
  BalanceState balanceState;
  char buf[MAX_MESSAGE_LEN];

  my_info_t me = {
    .id = id,
    .dist_info = info
  };

  uint8_t i;
  uint8_t last_order_time = 0;

  balanceState.s_balance                = info->balances[ id ];
  balanceState.s_time                   = 0;
  balanceState.s_balance_pending_in     = 0;
  history->s_history[ last_order_time ] = balanceState;

  int running = 1; 
  while( running ) {
    if( !receive_any( &me, &msg ) ) {
      switch( msg.s_header.s_type ) {
        case TRANSFER: {
          TransferOrder *order = (TransferOrder *) msg.s_payload;
          uint8_t cur_order_time = get_physical_time();

          for( i = last_order_time + 1; i < cur_order_time; i++ ) {
            balanceState.s_balance = info->balances[ id ]; 
            balanceState.s_time    = i;
            balanceState.s_balance_pending_in = 0;
            history->s_history[ i ] = balanceState;
          }
          
          if( order->s_src == id ) {
            snprintf( buf, sizeof(buf), log_transfer_out_fmt,
                                        get_physical_time(), order->s_src,
                                        order->s_amount, order->s_dst ); 
            fputs( buf, info->events_log );
            fputs( buf, stdout );

            info->balances[ id ] -= order->s_amount;

            msg.s_header.s_local_time = get_physical_time();
            send( &me, order->s_dst, &msg );
          } else if( order->s_dst == id ) {
            snprintf( buf, sizeof(buf), log_transfer_in_fmt,
                                        get_physical_time(), order->s_dst,
                                        order->s_amount, order->s_src); 
            fputs( buf, info->events_log );
            fputs( buf, stdout );

            Message stopMsg = {
              .s_header = {
                .s_magic = MESSAGE_MAGIC,
                .s_payload_len = 0,
                .s_type = ACK,
                .s_local_time = get_physical_time()
              }
            };
            info->balances[ id ] += order->s_amount;
            send( &me, PARENT_ID, &stopMsg );
          }

          balanceState.s_balance = info->balances[ id ]; 
          balanceState.s_time    = cur_order_time;
          balanceState.s_balance_pending_in = 0;

          history->s_history[ cur_order_time ] = balanceState;
          history->s_history_len = cur_order_time + 1;
          last_order_time = cur_order_time;
          break;
        }
        case STOP:
          running = 0;
          break;
      }
    }
  }
}

void child_phase3( dist_info_t *info, uint8_t id, BalanceHistory *history ) {
  char buf[MAX_MESSAGE_LEN];
  uint8_t i;

  my_info_t me = {
    .id = id,
    .dist_info = info
  };

  int size = snprintf( buf, sizeof(buf), log_done_fmt,
                                         get_physical_time(), id, 
                                         info->balances[ id ] );

  Message msg = {
    .s_header = {
      .s_magic = MESSAGE_MAGIC,
      .s_payload_len = size + 1,
      .s_type = DONE,
      .s_local_time = get_physical_time()
    }
  };

  fputs( buf, info->events_log );
  fputs( buf, stdout );
  strncpy( msg.s_payload, buf, sizeof( msg.s_payload ) );

  send_multicast( &me, &msg );

  for( i = 1; i <= info->x; i++ ) {
    if( i == me.id )
      continue;

    if( !receive( &me, i, &msg ) ) {
      if( msg.s_header.s_type != DONE ) {
        fprintf( stderr, "Message type INVALID (not DONE)!\n" );
        break;
      }
    }
  }

  snprintf( buf, sizeof(buf), log_received_all_done_fmt,
                              get_physical_time(), id ); 
  fputs( buf, info->events_log );
  fputs( buf, stdout );

  int time = get_physical_time();
  for( i = history->s_history_len; i <= time; i++ ) {
    history->s_history[i].s_balance = history->s_history[ history->s_history_len - 1].s_balance;
    history->s_history[i].s_time = i;
  }

  history->s_history_len = time+1;
   
  int wr_size = history->s_history_len * sizeof(history->s_history[0]);
  Message historyMsg = {
    .s_header = {
      .s_magic = MESSAGE_MAGIC,
      .s_payload_len = wr_size,
      .s_type = BALANCE_HISTORY,
      .s_local_time = time
    }
  };

  memcpy( historyMsg.s_payload, history, wr_size );
  send( &me, PARENT_ID, &historyMsg );
}

void child_workflow( dist_info_t *info, uint8_t id ) {
  BalanceHistory history = {
    .s_id = id
  };

  /* CHILD PHASE 0: Close all redundant descriptors */
  child_phase0(info, id);

  /* CHILD PHASE 1: Send STARTED message for all, receive STARTED
   * messages from other childs */
  child_phase1(info, id);

  /* CHILD PHASE 2: Do some useful work */ 
  child_phase2(info, id, &history);

  /* CHILD PHASE 3: Send DONE message for all, receive DONE messages from
   * other childs and exit */
  child_phase3(info, id, &history);
}