/* Copyright (c) 2009-2013. The SimGrid Team.
 * All rights reserved.                                                     */

/* This program is free software; you can redistribute it and/or modify it
 * under the terms of the license (GNU LGPL) which comes with this package. */

#include "private.h"
#include "simdag/simdag.h"
#include "xbt/misc.h"
#include "xbt/log.h"
#include <libgen.h>

XBT_LOG_NEW_DEFAULT_SUBCATEGORY(sd_daxparse, sd, "Parsing DAX files");

#undef CLEANUP
#include "dax_dtd.h"
#include "dax_dtd.c"

bool children_are_marked(SD_task_t task);
bool parents_are_marked(SD_task_t task);

/* Parsing helpers */
static void dax_parse_error(char *msg)
{
  fprintf(stderr, "Parse error on line %d: %s\n", dax_lineno, msg);
  xbt_abort();
}

static double dax_parse_double(const char *string)
{
  int ret = 0;
  double value;

  ret = sscanf(string, "%lg", &value);
  if (ret != 1)
    dax_parse_error(bprintf("%s is not a double", string));
  return value;
}

/* Ensure that transfer tasks have unique names even though a file is used
 * several times */

void uniq_transfer_task_name(SD_task_t task)
{
  SD_task_t child, parent;
  xbt_dynar_t children, parents;
  char *new_name;

  children = SD_task_get_children(task);
  parents = SD_task_get_parents(task);

  xbt_dynar_get_cpy(children, 0, &child);
  xbt_dynar_get_cpy(parents, 0, &parent);

  new_name = bprintf("%s_%s_%s",
                     SD_task_get_name(parent),
                     SD_task_get_name(task), SD_task_get_name(child));

  SD_task_set_name(task, new_name);

  xbt_dynar_free_container(&children);
  xbt_dynar_free_container(&parents);
  free(new_name);
}

bool children_are_marked(SD_task_t task){
  SD_task_t child_task = NULL;
  bool all_marked = true;
  SD_dependency_t depafter = NULL;
  unsigned int count;
  xbt_dynar_foreach(task->tasks_after,count,depafter){
    child_task = depafter->dst;
    //test marked
    if(child_task->marked == 0) {
      all_marked = false;
      break;
    }
    child_task = NULL;
  }
  return all_marked;
}

bool parents_are_marked(SD_task_t task){
  SD_task_t parent_task = NULL;
  bool all_marked = true;
  SD_dependency_t depbefore = NULL;
  unsigned int count;
  xbt_dynar_foreach(task->tasks_before,count,depbefore){
    parent_task = depbefore->src;
    //test marked
    if(parent_task->marked == 0) {
      all_marked = false;
      break;
    }
    parent_task = NULL;
  }
  return all_marked;
}

bool acyclic_graph_detail(xbt_dynar_t dag){
  unsigned int count=0, count_current=0;
  bool all_marked = true;
  SD_task_t task = NULL, parent_task = NULL, child_task = NULL;
  SD_dependency_t depbefore = NULL, depafter = NULL;
  xbt_dynar_t next = NULL, current = xbt_dynar_new(sizeof(SD_task_t),NULL);

  xbt_dynar_foreach(dag,count,task){
    if(task->kind == SD_TASK_COMM_E2E) continue;
    task->marked = 0;
    if(xbt_dynar_is_empty(task->tasks_after)){
      xbt_dynar_push(current, &task);
    }
  }
  task = NULL;
  count = 0;
  //test if something has to be done for the next iteration
  while(!xbt_dynar_is_empty(current)){
    next = xbt_dynar_new(sizeof(SD_task_t),NULL);
    //test if the current iteration is done
    count_current=0;
    xbt_dynar_foreach(current,count_current,task){
      if (task == NULL) continue;
      count = 0;
      //push task in next
      task->marked = 1;
      count = 0;
      xbt_dynar_foreach(task->tasks_before,count,depbefore){
        parent_task = depbefore->src;
        if(parent_task->kind == SD_TASK_COMM_E2E){
          unsigned int j=0;
          parent_task->marked = 1;
          SD_task_t parent_task_2 = NULL;
          xbt_dynar_foreach(parent_task->tasks_before,j,depbefore){
            parent_task_2 = depbefore->src;
            if(children_are_marked(parent_task_2))
              xbt_dynar_push(next, &parent_task_2);
          }
        } else{
          if(children_are_marked(parent_task))
            xbt_dynar_push(next, &parent_task);
        }
        parent_task = NULL;
      }
      task = NULL;
      count = 0;
    }
    xbt_dynar_free(&current);
    current = next;
    next = NULL;
  }
  xbt_dynar_free(&current);
  current = NULL;
  all_marked = true;
  xbt_dynar_foreach(dag,count,task){
    if(task->kind == SD_TASK_COMM_E2E) continue;
    //test if all tasks are marked
    if(task->marked == 0){
      XBT_WARN("the task %s is not marked",task->name);
      all_marked = false;
      break;
    }
  }
  task = NULL;
  if(!all_marked){
    XBT_VERB("there is at least one cycle in your task graph");

    current = xbt_dynar_new(sizeof(SD_task_t),NULL);
    xbt_dynar_foreach(dag,count,task){
      if(task->kind == SD_TASK_COMM_E2E) continue;
      if(xbt_dynar_is_empty(task->tasks_before)){
        xbt_dynar_push(current, &task);
      }
    }

    count = 0;
    task = NULL;
    xbt_dynar_foreach(dag,count,task){
      if(task->kind == SD_TASK_COMM_E2E) continue;
      if(xbt_dynar_is_empty(task->tasks_before)){
        task->marked = 1;
        xbt_dynar_push(current, &task);
      }
    }
    task = NULL;
    count = 0;
    //test if something has to be done for the next iteration
    while(!xbt_dynar_is_empty(current)){
      next = xbt_dynar_new(sizeof(SD_task_t),NULL);
      //test if the current iteration is done
      count_current=0;
      xbt_dynar_foreach(current,count_current,task){
        if (task == NULL) continue;
        count = 0;
        //push task in next
        task->marked = 1;
        count = 0;
        xbt_dynar_foreach(task->tasks_after,count,depafter){
          child_task = depbefore->dst;
          if(child_task->kind == SD_TASK_COMM_E2E){
            unsigned int j=0;
            child_task->marked = 1;
            SD_task_t child_task_2 = NULL;
            xbt_dynar_foreach(child_task->tasks_after,j,depafter){
              child_task_2 = depbefore->dst;
              if(parents_are_marked(child_task_2))
                xbt_dynar_push(next, &child_task_2);
            }
          } else{
            if(parents_are_marked(child_task))
              xbt_dynar_push(next, &child_task);
          }
          child_task = NULL;
        }
        task = NULL;
        count = 0;
      }
      xbt_dynar_free(&current);
      current = next;
      next = NULL;
    }
    xbt_dynar_free(&current);
    current = NULL;
    all_marked = true;
    xbt_dynar_foreach(dag,count,task){
      if(task->kind == SD_TASK_COMM_E2E) continue;
      //test if all tasks are marked
      if(task->marked == 0){
        XBT_WARN("the task %s is in a cycle",task->name);
        all_marked = false;
      }
    }
  }
  return all_marked;
}



static YY_BUFFER_STATE input_buffer;

static xbt_dynar_t result;
static xbt_dict_t jobs;
static xbt_dict_t files;
static SD_task_t current_job;
static SD_task_t root_task, end_task;

static void dax_task_free(void *task)
{
  SD_task_t t = task;
  SD_task_destroy(t);
}

/** @brief loads a DAX file describing a DAG
 * 
 * See https://confluence.pegasus.isi.edu/display/pegasus/WorkflowGenerator
 * for more details.
 */
xbt_dynar_t SD_daxload(const char *filename)
{
  xbt_dict_cursor_t cursor;
  SD_task_t file;
  char *name;
  FILE *in_file = fopen(filename, "r");
  xbt_assert(in_file, "Unable to open \"%s\"\n", filename);
  input_buffer = dax__create_buffer(in_file, 10);
  dax__switch_to_buffer(input_buffer);
  dax_lineno = 1;

  result = xbt_dynar_new(sizeof(SD_task_t), dax_task_free);
  files = xbt_dict_new_homogeneous(&dax_task_free);
  jobs = xbt_dict_new_homogeneous(NULL);
  root_task = SD_task_create_comp_seq("root", NULL, 0);
  /* by design the root task is always SCHEDULABLE */
  __SD_task_set_state(root_task, SD_SCHEDULABLE);

  xbt_dynar_push(result, &root_task);
  end_task = SD_task_create_comp_seq("end", NULL, 0);

  int res = dax_lex();
  if (res != 0)
    xbt_die("Parse error in %s: %s", filename, dax__parse_err_msg());
  dax__delete_buffer(input_buffer);
  fclose(in_file);
  dax_lex_destroy();
  xbt_dict_free(&jobs);

  /* And now, post-process the files.
   * We want a file task per pair of computation tasks exchanging the file. Duplicate on need
   * Files not produced in the system are said to be produced by root task (top of DAG).
   * Files not consumed in the system are said to be consumed by end task (bottom of DAG).
   */

  xbt_dict_foreach(files, cursor, name, file) {
    unsigned int cpt1, cpt2;
    SD_task_t newfile;
    SD_dependency_t depbefore, depafter;
    if (xbt_dynar_is_empty(file->tasks_before)) {
      xbt_dynar_foreach(file->tasks_after, cpt2, depafter) {
        newfile = SD_task_create_comm_e2e(file->name, NULL, file->amount);
        SD_task_dependency_add(NULL, NULL, root_task, newfile);
        SD_task_dependency_add(NULL, NULL, newfile, depafter->dst);
#ifdef HAVE_TRACING
        if (depafter->src){
          const char *category = depafter->src->category;
          if (category){
            TRACE_category (category);
            TRACE_sd_set_task_category(newfile, category);
          }
        }
#endif
        xbt_dynar_push(result, &newfile);
      }
    } else if (xbt_dynar_is_empty(file->tasks_after)) {
      xbt_dynar_foreach(file->tasks_before, cpt2, depbefore) {
        newfile = SD_task_create_comm_e2e(file->name, NULL, file->amount);
        SD_task_dependency_add(NULL, NULL, depbefore->src, newfile);
        SD_task_dependency_add(NULL, NULL, newfile, end_task);
#ifdef HAVE_TRACING
        if (depbefore->src){
          const char *category = depbefore->src->category;
          if (category){
            TRACE_category (category);
            TRACE_sd_set_task_category(newfile, category);
          }
        }
#endif
        xbt_dynar_push(result, &newfile);
      }
    } else {
      xbt_dynar_foreach(file->tasks_before, cpt1, depbefore) {
        xbt_dynar_foreach(file->tasks_after, cpt2, depafter) {
          if (depbefore->src == depafter->dst) {
            XBT_WARN
                ("File %s is produced and consumed by task %s. This loop dependency will prevent the execution of the task.",
                 file->name, depbefore->src->name);
          }
          newfile = SD_task_create_comm_e2e(file->name, NULL, file->amount);
          SD_task_dependency_add(NULL, NULL, depbefore->src, newfile);
          SD_task_dependency_add(NULL, NULL, newfile, depafter->dst);
#ifdef HAVE_TRACING
          if (depbefore->src){
            const char *category = depbefore->src->category;
            if (category){
              TRACE_category (category);
              TRACE_sd_set_task_category(newfile, category);
            }
          }
#endif
          xbt_dynar_push(result, &newfile);
        }
      }
    }
  }

  /* Push end task last */
  xbt_dynar_push(result, &end_task);

  /* Free previous copy of the files */
  xbt_dict_free(&files);
  unsigned int cpt;
  xbt_dynar_foreach(result, cpt, file) {
    if (SD_task_get_kind(file) == SD_TASK_COMM_E2E) {
      uniq_transfer_task_name(file);
    } else if (SD_task_get_kind(file) == SD_TASK_COMP_SEQ){
      /* If some tasks do not take files as input, connect them to the root, if
       * they don't produce files, connect them to the end node.
       */
      if ((file != root_task) && xbt_dynar_is_empty(file->tasks_before)) {
        SD_task_dependency_add(NULL, NULL, root_task, file);
      }
      if ((file != end_task) && xbt_dynar_is_empty(file->tasks_after)) {
        SD_task_dependency_add(NULL, NULL, file, end_task);
      }
    }
  }

  if (!acyclic_graph_detail(result)){
    XBT_ERROR("The DAX described in %s is not a DAG. It contains a cycle.",
              basename((char*)filename));
    xbt_dynar_foreach(result, cpt, file)
      SD_task_destroy(file);
     xbt_dynar_free_container(&result);
    return NULL;
  } else {
    return result;
  }
}

void STag_dax__adag(void)
{
  _XBT_GNUC_UNUSED double version;
  version = dax_parse_double(A_dax__adag_version);

  xbt_assert(version == 2.1,
              "Expected version 2.1 in <adag> tag, got %f. Fix the parser or your file",
              version);
}

void STag_dax__job(void)
{
  double runtime = dax_parse_double(A_dax__job_runtime);
  char *name = bprintf("%s@%s", A_dax__job_id, A_dax__job_name);
  runtime *= 4200000000.;       /* Assume that timings were done on a 4.2GFlops machine. I mean, why not? */
//  XBT_INFO("See <job id=%s runtime=%s %.0f>",A_dax__job_id,A_dax__job_runtime,runtime);
  current_job = SD_task_create_comp_seq(name, NULL, runtime);
#ifdef HAVE_TRACING
  char *category = A_dax__job_name;
  if (category){
    TRACE_category (category);
    TRACE_sd_set_task_category(current_job, category);
  }
#endif
  xbt_dict_set(jobs, A_dax__job_id, current_job, NULL);
  free(name);
  xbt_dynar_push(result, &current_job);
}

void STag_dax__uses(void)
{
  SD_task_t file;
  double size = dax_parse_double(A_dax__uses_size);
  int is_input = (A_dax__uses_link == A_dax__uses_link_input);

//  XBT_INFO("See <uses file=%s %s>",A_dax__uses_file,(is_input?"in":"out"));
  file = xbt_dict_get_or_null(files, A_dax__uses_file);
  if (file == NULL) {
    file = SD_task_create_comm_e2e(A_dax__uses_file, NULL, size);
    xbt_dict_set(files, A_dax__uses_file, file, NULL);
  } else {
    if (SD_task_get_amount(file) != size) {
      XBT_WARN("Ignoring file %s size redefinition from %.0f to %.0f",
            A_dax__uses_file, SD_task_get_amount(file), size);
    }
  }
  if (is_input) {
    SD_task_dependency_add(NULL, NULL, file, current_job);
  } else {
    SD_task_dependency_add(NULL, NULL, current_job, file);
    if (xbt_dynar_length(file->tasks_before) > 1) {
      XBT_WARN("File %s created at more than one location...", file->name);
    }
  }
}

static SD_task_t current_child;
void STag_dax__child(void)
{
  current_child = xbt_dict_get_or_null(jobs, A_dax__child_ref);
  if (current_child == NULL)
    dax_parse_error(bprintf
                    ("Asked to add dependencies to the non-existent %s task",
                     A_dax__child_ref));
}

void ETag_dax__child(void)
{
  current_child = NULL;
}

void STag_dax__parent(void)
{
  SD_task_t parent = xbt_dict_get_or_null(jobs, A_dax__parent_ref);
  if (parent == NULL)
    dax_parse_error(bprintf
                    ("Asked to add a dependency from %s to %s, but %s does not exist",
                     current_child->name, A_dax__parent_ref,
                     A_dax__parent_ref));
  SD_task_dependency_add(NULL, NULL, parent, current_child);
  XBT_DEBUG("Control-flow dependency from %s to %s", current_child->name,
         parent->name);
}

void ETag_dax__adag(void)
{
//  XBT_INFO("See </adag>");
}

void ETag_dax__job(void)
{
  current_job = NULL;
//  XBT_INFO("See </job>");
}

void ETag_dax__parent(void)
{
//  XBT_INFO("See </parent>");
}

void ETag_dax__uses(void)
{
//  XBT_INFO("See </uses>");
}
