/*
 * Copyright © 2008, 2009 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
#include <cstdlib>
#include <cstdio>
#include <getopt.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include "ast.h"
#include "glsl_parser_extras.h"
#include "glsl_parser.h"
#include "ir_optimization.h"
#include "ir_print_visitor.h"
#include "program.h"

/* Returned string will have 'ctx' as its talloc owner. */
static char *
load_text_file(void *ctx, const char *file_name, size_t *size)
{
	char *text = NULL;
	struct stat st;
	ssize_t total_read = 0;
	int fd = open(file_name, O_RDONLY);

	*size = 0;
	if (fd < 0) {
		return NULL;
	}

	if (fstat(fd, & st) == 0) {
	   text = (char *) talloc_size(ctx, st.st_size + 1);
		if (text != NULL) {
			do {
				ssize_t bytes = read(fd, text + total_read,
						     st.st_size - total_read);
				if (bytes < 0) {
					free(text);
					text = NULL;
					break;
				}

				if (bytes == 0) {
					break;
				}

				total_read += bytes;
			} while (total_read < st.st_size);

			text[total_read] = '\0';
			*size = total_read;
		}
	}

	close(fd);

	return text;
}


void
usage_fail(const char *name)
{
      printf("%s <filename.frag|filename.vert>\n", name);
      exit(EXIT_FAILURE);
}


int dump_ast = 0;
int dump_hir = 0;
int dump_lir = 0;
int do_link = 0;

const struct option compiler_opts[] = {
   { "dump-ast", 0, &dump_ast, 1 },
   { "dump-hir", 0, &dump_hir, 1 },
   { "dump-lir", 0, &dump_lir, 1 },
   { "link",     0, &do_link,  1 },
   { NULL, 0, NULL, 0 }
};

void
compile_shader(struct glsl_shader *shader)
{
   struct _mesa_glsl_parse_state *state;

   state = talloc_zero(talloc_parent(shader), struct _mesa_glsl_parse_state);

   switch (shader->Type) {
   case GL_VERTEX_SHADER:   state->target = vertex_shader; break;
   case GL_FRAGMENT_SHADER: state->target = fragment_shader; break;
   case GL_GEOMETRY_SHADER: state->target = geometry_shader; break;
   }

   state->scanner = NULL;
   state->translation_unit.make_empty();
   state->symbols = new(shader) glsl_symbol_table;
   state->info_log = talloc_strdup(shader, "");
   state->error = false;
   state->temp_index = 0;
   state->loop_or_switch_nesting = NULL;
   state->ARB_texture_rectangle_enable = true;

   /* Create a new context for the preprocessor output.  Ultimately, this
    * should probably be the parser context, but there isn't one yet.
   */
   const char *source = shader->Source;
   state->error = preprocess(shader, &source, &state->info_log);

   if (!state->error) {
      _mesa_glsl_lexer_ctor(state, source);
      _mesa_glsl_parse(state);
      _mesa_glsl_lexer_dtor(state);
   }

   if (dump_ast) {
      foreach_list_const(n, &state->translation_unit) {
	 ast_node *ast = exec_node_data(ast_node, n, link);
	 ast->print();
      }
      printf("\n\n");
   }

   shader->ir.make_empty();
   if (!state->error && !state->translation_unit.is_empty())
      _mesa_ast_to_hir(&shader->ir, state);

   validate_ir_tree(&shader->ir);

   /* Print out the unoptimized IR. */
   if (!state->error && dump_hir) {
      _mesa_print_ir(&shader->ir, state);
   }

   /* Optimization passes */
   if (!state->error && !shader->ir.is_empty()) {
      bool progress;
      do {
	 progress = false;

	 progress = do_function_inlining(&shader->ir) || progress;
	 progress = do_if_simplification(&shader->ir) || progress;
	 progress = do_copy_propagation(&shader->ir) || progress;
	 progress = do_dead_code_local(&shader->ir) || progress;
	 progress = do_dead_code_unlinked(state, &shader->ir) || progress;
	 progress = do_constant_variable_unlinked(&shader->ir) || progress;
	 progress = do_constant_folding(&shader->ir) || progress;
	 progress = do_vec_index_to_swizzle(&shader->ir) || progress;
	 progress = do_swizzle_swizzle(&shader->ir) || progress;
      } while (progress);
   }

   validate_ir_tree(&shader->ir);

   /* Print out the resulting IR */
   if (!state->error && dump_lir) {
      _mesa_print_ir(&shader->ir, state);
   }

   shader->symbols = state->symbols;
   shader->CompileStatus = !state->error;

   if (shader->InfoLog)
      talloc_free(shader->InfoLog);

   shader->InfoLog = state->info_log;

   talloc_free(state);

   return;
}

int
main(int argc, char **argv)
{
   int status = EXIT_SUCCESS;

   int c;
   int idx = 0;
   while ((c = getopt_long(argc, argv, "", compiler_opts, &idx)) != -1)
      /* empty */ ;


   if (argc <= optind)
      usage_fail(argv[0]);

   struct glsl_program *whole_program;

   whole_program = talloc_zero (NULL, struct glsl_program);
   assert(whole_program != NULL);

   for (/* empty */; argc > optind; optind++) {
      whole_program->Shaders = (struct glsl_shader **)
	 talloc_realloc(whole_program, whole_program->Shaders,
			struct glsl_shader *, whole_program->NumShaders + 1);
      assert(whole_program->Shaders != NULL);

      struct glsl_shader *shader = talloc_zero(whole_program, glsl_shader);

      whole_program->Shaders[whole_program->NumShaders] = shader;
      whole_program->NumShaders++;

      const unsigned len = strlen(argv[optind]);
      if (len < 6)
	 usage_fail(argv[0]);

      const char *const ext = & argv[optind][len - 5];
      if (strncmp(".vert", ext, 5) == 0)
	 shader->Type = GL_VERTEX_SHADER;
      else if (strncmp(".geom", ext, 5) == 0)
	 shader->Type = GL_GEOMETRY_SHADER;
      else if (strncmp(".frag", ext, 5) == 0)
	 shader->Type = GL_FRAGMENT_SHADER;
      else
	 usage_fail(argv[0]);

      shader->Source = load_text_file(whole_program,
				      argv[optind], &shader->SourceLen);
      if (shader->Source == NULL) {
	 printf("File \"%s\" does not exist.\n", argv[optind]);
	 exit(EXIT_FAILURE);
      }

      compile_shader(shader);

      if (!shader->CompileStatus) {
	 printf("Info log for %s:\n%s\n", argv[optind], shader->InfoLog);
	 status = EXIT_FAILURE;
	 break;
      }
   }

   if ((status == EXIT_SUCCESS) && do_link)  {
      link_shaders(whole_program);
      status = (whole_program->LinkStatus) ? EXIT_SUCCESS : EXIT_FAILURE;
   }

   talloc_free(whole_program);
   _mesa_glsl_release_types();

   return status;
}