#include <stddef.h>
#include <stdint.h>
#include "ipcpipe.h"
#include "ipc/pipe/pipe.h"
#include "sysdefs/ipcpipe.h"
#include "dlmalloc/malloc.h"
#include "proc/proc.h"
#include "spinlock/spinlock.h"
#include "errors.h"
#include "util/util.h"
#include "kprintf.h"

int32_t SYSCALL5(sys_ipcpipe, pid1, pipenum1, cmd1, buffer1, len1) {
  uint64_t pid = pid1;
  uint64_t pipenum = pipenum1;
  uint64_t cmd = cmd1;
  int32_t ret = E_OK;
  
  if (pid == -1) {
    pid = PROCS.current->pid;
  }

  spinlock_acquire(&PROCS.spinlock);
  Proc *proc = NULL;
  LL_FINDPROP(PROCS.procs, proc, pid, pid);
  spinlock_release(&PROCS.spinlock);

  if (proc == NULL) {
    ret = E_INVALIDARGUMENT;
    goto done;
  }

  switch (cmd) {
    case IPCPIPE_MAKE: {
      if (pipenum >= PROC_PIPEHANDLES_MAX) {
        ret = E_NOMEMORY;
        goto done;
      }

      IpcPipe *pipe = dlmalloc(sizeof(*pipe));
      if (pipe == NULL) {
        ret = E_NOMEMORY;
        goto done;
      }

      if ((ret = ipc_pipeinit(pipe, proc->pid)) < 0) {
        ret = E_NOMEMORY;
        goto done;
      }

      spinlock_acquire(&proc->pipes_spinlock);
      if (proc->pipes[pipenum] != NULL) {
        spinlock_release(&proc->pipes_spinlock);
        ipc_pipefree(pipe);
        dlfree(pipe);
        ret = E_RESOURCEAVAIL;
        goto done;
      }
      proc->pipes[pipenum] = pipe;
      spinlock_release(&proc->pipes_spinlock);

      ret = E_OK;
    } break;
    case IPCPIPE_DELETE: {
      if (pipenum >= PROC_PIPEHANDLES_MAX) {
        ret = E_NOMEMORY;
        goto done;
      }

      spinlock_acquire(&proc->pipes_spinlock);
      if (proc->pipes[pipenum] != NULL && proc->pid == proc->pipes[pipenum]->ownerpid) {
        ipc_pipefree(proc->pipes[pipenum]);
        dlfree(proc->pipes[pipenum]);
      }
      proc->pipes[pipenum] = NULL;
      spinlock_release(&proc->pipes_spinlock);
      ret = E_OK;
    } break;
    case IPCPIPE_WRITE: {
      if (pipenum >= PROC_PIPEHANDLES_MAX) {
        ret = E_INVALIDARGUMENT;
        goto done;
      }

      const uint8_t *const buffer = (const uint8_t *const)buffer1;
      if (buffer == NULL) {
        ret = E_INVALIDARGUMENT;
        goto done;
      }

      spinlock_acquire(&proc->pipes_spinlock);
      IpcPipe *pipe = proc->pipes[pipenum];
      spinlock_release(&proc->pipes_spinlock);

      if (pipe == NULL) {
        ret = E_INVALIDARGUMENT;
        goto done;
      }

      ret = ipc_pipewrite(pipe, buffer, len1);
    } break;
    case IPCPIPE_READ: {
      if (pipenum >= PROC_PIPEHANDLES_MAX) {
        ret = E_INVALIDARGUMENT;
        goto done;
      }

      uint8_t *const buffer = (uint8_t *const)buffer1;
      if (buffer == NULL) {
        ret = E_INVALIDARGUMENT;
        goto done;
      }

      spinlock_acquire(&proc->pipes_spinlock);
      IpcPipe *pipe = proc->pipes[pipenum];
      spinlock_release(&proc->pipes_spinlock);
      
      if (pipe == NULL) {
        ret = E_INVALIDARGUMENT;
        goto done;
      }

      ret = ipc_piperead(pipe, buffer, len1);
    } break;
    case IPCPIPE_REPLACE: {
      if (pipenum >= PROC_PIPEHANDLES_MAX) {
        ret = E_NOMEMORY;
        goto done;
      }

      uint64_t pid2 = buffer1;
      uint64_t pipenum2 = len1;

      spinlock_acquire(&PROCS.spinlock);
      Proc *proc2 = NULL;
      LL_FINDPROP(PROCS.procs, proc2, pid, pid2);
      spinlock_release(&PROCS.spinlock);

      if (proc2 == NULL) {
        ret = E_INVALIDARGUMENT;
        goto done;
      }

      if (pipenum2 >= PROC_PIPEHANDLES_MAX) {
        ret = E_NOMEMORY;
        goto done;
      }
      
      spinlock_acquire(&proc2->pipes_spinlock);
      spinlock_acquire(&proc->pipes_spinlock);

      if (proc->pipes[pipenum] != NULL && proc->pid == proc->pipes[pipenum]->ownerpid) {
        ipc_pipefree(proc->pipes[pipenum]);
        dlfree(proc->pipes[pipenum]);
      }
      proc->pipes[pipenum] = proc2->pipes[pipenum2];

      spinlock_release(&proc->pipes_spinlock);
      spinlock_release(&proc2->pipes_spinlock);
    } break;
    default: {
      ret = E_INVALIDARGUMENT;
    } break;
  }

done:
  return ret;
}