#include "compiler.h"
#include "lib/commons.h"
#include "lib/mod.h"
#include "node.h"

void compiler_init(compiler_t* compiler,
                   mod_t* mod,
                   sym_t* sym,
                   tysy_t* tysy,
                   err_t* err)
{
  assert(compiler);
  assert(sym);
  assert(tysy);
  assert(err);

  compiler->mod = mod;
  compiler->sym = sym;
  compiler->tysy = tysy;
  compiler->err = err;
}

void compiler_free(compiler_t* compiler)
{
  assert(compiler);
}

int compiler_run(compiler_t* compiler, node_t* node)
{
  assert(compiler);
  assert(node);

  switch (node->type)
    {
    case NODE_MOD: {
      for (size_t i=0; i<node->children.size; i++)
        {
          compiler_run(compiler, (node_t*) node->children.data[i]);
        }
    } break;

    case NODE_NUM: {
      double value = atof(node->value.data);
      value_t* val = tysy_new_num(compiler->tysy, value, node->line);
      Opcode op = OP_PUSH;
      param_t param = (param_t) mod_push_new_value(compiler->mod, val);

      mod_push_instr(compiler->mod, op, param);

    } break;

    case NODE_BOOL: {
      int value = strcmp(node->value.data, "true") == 0;
      value_t* val = tysy_new_bool(compiler->tysy, value, node->line);
      Opcode op = OP_PUSH;
      param_t param = (param_t) mod_push_new_value(compiler->mod, val);

      mod_push_instr(compiler->mod, op, param);
    } break;

    case NODE_STR: {
      char* value = node->value.data;
      value_t* val = tysy_new_str(compiler->tysy, value, node->line);
      Opcode op = OP_PUSH;
      param_t param = (param_t) mod_push_new_value(compiler->mod, val);

      mod_push_instr(compiler->mod, op, param);
    } break;

    case NODE_ASSERT: {
      assert(node->children.size == 1);
      compiler_run(compiler, node_child(node, 0));
      mod_push_instr(compiler->mod, OP_ASSERT, RZ_NO_PARAM);
    } break;

    case NODE_NE:
    case NODE_EQ: {
      assert(node->children.size == 2);

      for (size_t i=0; i<node->children.size; i++)
        {
          compiler_run(compiler, node_child(node, i));
        }

      mod_push_instr(compiler->mod,
                     node->type == NODE_EQ ? OP_EQ : OP_NE, RZ_NO_PARAM);
    } break;

    case NODE_LT:
    case NODE_LE:
    case NODE_GT:
    case NODE_GE: {
      assert(node->children.size == 2);

      for (size_t i=0; i<node->children.size; i++)
        {
          compiler_run(compiler, node_child(node, i));
        }

      Opcode op;
      switch (node->type)
        {
        case NODE_LT: op = OP_LT; break;
        case NODE_LE: op = OP_LE; break;
        case NODE_GT: op = OP_GT; break;
        case NODE_GE: op = OP_GE; break;
        default: assert(0);
        }

      mod_push_instr(compiler->mod, op, RZ_NO_PARAM);

    } break;

    case NODE_ADD:
    case NODE_SUB:
    case NODE_MUL:
    case NODE_DIV:
    case NODE_MODULO:
    case NODE_POW: {
        for (size_t i=0; i<node->children.size; i++)
        {
          compiler_run(compiler, node_child(node, i));
        }

        Opcode op;

        if (node->type == NODE_SUB
            && node->children.size == 1)
          {
            op = OP_USUB;
          }
        else if (node->type == NODE_ADD
                 && node_find_first(node, NODE_STR))
          {
            op = OP_STRCAT;
          }
        else if (node->type == NODE_MUL
                 && node_find_first(node, NODE_STR)
                 && node_find_first(node, NODE_NUM))
          {
            op = OP_STRDUP;
          }
        else
          {
            switch (node->type)
              {
              case NODE_ADD: op = OP_ADD; break;
              case NODE_SUB: op = OP_SUB; break;
              case NODE_MUL: op = OP_MUL; break;
              case NODE_DIV: op = OP_DIV; break;
              case NODE_MODULO: op = OP_MODULO; break;
              case NODE_POW: op = OP_POW; break;
              default: assert(0);
              }
          }

      mod_push_instr(compiler->mod, op, RZ_NO_PARAM);

    } break;

    case NODE_AND: {
      size_t const SZ = 512;
      size_t to_false[SZ];
      size_t sz = 0;

      for (size_t i=0; i<node->children.size; i++)
        {
          compiler_run(compiler, node_child(node, i));
          size_t addr = mod_push_instr(compiler->mod, OP_BRF, RZ_NO_PARAM);
          to_false[sz++] = addr;
        }

      // True case
      value_t* t = tysy_new_bool(compiler->tysy, 1, node->line);
      param_t t_param = mod_push_new_value(compiler->mod, t);
      mod_push_instr(compiler->mod, OP_PUSH, t_param);
      size_t to_end = mod_push_instr(compiler->mod, OP_BR, RZ_NO_PARAM);

      // False case
      size_t program_sz = compiler->mod->program.size;
      for (size_t i=0; i<sz; i++)
        {
          compiler->mod->program.params[to_false[i]] = program_sz;
        }

      value_t* f = tysy_new_bool(compiler->tysy, 0, node->line);
      param_t f_param = mod_push_new_value(compiler->mod, f);
      mod_push_instr(compiler->mod, OP_PUSH, f_param);

      compiler->mod->program.params[to_end] = compiler->mod->program.size;

    } break;

    case NODE_OR: {
      size_t const SZ = 512;
      size_t to_true[SZ];
      size_t sz = 0;

      for (size_t i=0; i<node->children.size; i++)
        {
          compiler_run(compiler, node_child(node, i));
          size_t addr = mod_push_instr(compiler->mod, OP_BRT, RZ_NO_PARAM);
          to_true[sz++] = addr;
        }

      // False case
      value_t* f = tysy_new_bool(compiler->tysy, 0, node->line);
      param_t f_param = mod_push_new_value(compiler->mod, f);
      mod_push_instr(compiler->mod, OP_PUSH, f_param);
      size_t to_end = mod_push_instr(compiler->mod, OP_BR, RZ_NO_PARAM);

      // True case
      size_t program_sz = compiler->mod->program.size;
      for (size_t i=0; i<sz; i++)
        {
          compiler->mod->program.params[to_true[i]] = program_sz;
        }

      value_t* t = tysy_new_bool(compiler->tysy, 1, node->line);
      param_t t_param = mod_push_new_value(compiler->mod, t);
      mod_push_instr(compiler->mod, OP_PUSH, t_param);

      compiler->mod->program.params[to_end] = compiler->mod->program.size;

    } break;

    case NODE_NOT: {
      assert(node->children.size > 0);
      compiler_run(compiler, (node_t*) node->children.data[0]);
      mod_push_instr(compiler->mod, OP_NOT, RZ_NO_PARAM);
    } break;

    case NODE_VARDECL: {
      char* name = ((node_t*) node->children.data[0])->value.data;
      sym_entry_t* entry  = sym_try_find_by_name(compiler->sym, name);
      assert(entry);
      int id = entry->id;
      compiler_run(compiler, (node_t*) node->children.data[1]);
      mod_push_instr(compiler->mod, OP_STORE, id);
    } break;

    case NODE_IDENT: {
      char* name = node->value.data;
      sym_entry_t* entry = sym_try_find_by_name(compiler->sym, name);

      if (!entry)
        {
          char msg[RZ_STR_LIMIT];
          snprintf(msg, RZ_STR_LIMIT, "%s is undefined.",
                   name);

          err_fatal(compiler->err, msg, node->line);
          return -1;
        }
      else
        {
          int id = entry->id;
          mod_push_instr(compiler->mod, OP_LOAD, id);
        }
    } break;

    default: {
      fprintf(stderr, "Cannot compile unknown node '%s'",
              NodeTypeStr[node->type]);
      abort();
    } break;
    }

  return 0;
}