#define B_IMPLEMENTATION
#include "src/b.h"

int debug_level = 1;

void
debug_or_release(B_Cmd* cmd)
{
  if (debug_level == 0)
    b_cmd_append(cmd, "-O3", "-s");
  else if (debug_level == 1)
    b_cmd_append(cmd, "-O2", "-ggdb", "-DVKDEBUG");
  else if (debug_level == 2)
    b_cmd_append(cmd, "-O1", "-ggdb", "-DVKDEBUG");
  else
    b_cmd_append(cmd, "-O0", "-ggdb", "-DVKDEBUG");
}

void
inlcude_dirs(B_Cmd* cmd)
{
  b_cmd_append(cmd, "-I./src/");
  b_cmd_append(cmd, "-I./lib");
  b_cmd_append(cmd, "-I./lib/imgui-1.90.7");
}  

void
cflags(B_Cmd* cmd)
{
  b_cmd_append(cmd, "-Wall", "-Wextra");

  debug_or_release(cmd);

  b_cmd_append(cmd, "-march=native");
  b_cmd_append(cmd, "-fno-math-errno", "-funroll-loops");
  b_cmd_append(cmd, "-flto", "-pthread");

  inlcude_dirs(cmd);
}

void cxxflags(B_Cmd *cmd)
{
  b_cmd_append(cmd, "-Wall", "-Wextra");
  b_cmd_append(cmd, "-Wno-string-plus-int", "-Wno-nullability-completeness", "-Wno-unused-function", "-Wno-missing-field-initializers", "-Wno-unused-parameter", "-Wno-unused-variable");

  debug_or_release(cmd);

  b_cmd_append(cmd, "-march=native");
  b_cmd_append(cmd, "-fno-math-errno", "-funroll-loops");
  b_cmd_append(cmd, "-flto", "-pthread");

  inlcude_dirs(cmd);
  //b_cmd_append(cmd, "-O3");
}

void cxx(B_Cmd *cmd)
{
  b_cmd_append(cmd, "clang");
  cxxflags(cmd);
}

void cc(B_Cmd *cmd)
{
  b_cmd_append(cmd, "clang");
  cflags(cmd);
}

void libs(B_Cmd *cmd)
{
  b_cmd_append(cmd, "-lSDL2", "-lm", "-lvulkan", "-lshaderc_shared", "-lstdc++");
}

bool
build_c(bool         force,
        B_Cmd*       cmd,
        const char** input_paths,
        size_t       input_paths_len,
        const char** dep_paths,
        size_t       dep_paths_len,
        const char*  output_path)
{
  int rebuild_is_needed =
    b_needs_rebuild(output_path, input_paths, input_paths_len);
  int dep_rebuild = b_needs_rebuild(output_path, dep_paths, dep_paths_len);
  
  if (rebuild_is_needed < 0 || dep_rebuild < 0) return false;

  if (force || rebuild_is_needed || dep_rebuild) {
    cmd->count = 0;
    cc(cmd);
    b_cmd_append(cmd, "-o", output_path);
    b_da_append_many(cmd, input_paths, input_paths_len);
    libs(cmd);
    return b_cmd_run_sync(*cmd);
  }

  b_log(B_INFO, "%s is up-to-date", output_path);
  return true;
}

bool
compile_cxx(bool         force,
            B_Cmd*       cmd,
            const char** input_paths,
            size_t       input_paths_len,
            const char** dep_paths,
            size_t       dep_paths_len,
            const char*  output_path)
{
  int rebuild_is_needed = b_needs_rebuild(output_path, input_paths, input_paths_len);
  int dep_rebuild = b_needs_rebuild(output_path, dep_paths, dep_paths_len);
  
  if (rebuild_is_needed < 0 || dep_rebuild < 0) return false;

  if (force || rebuild_is_needed || dep_rebuild) {
    cmd->count = 0;
    cxx(cmd);
    b_cmd_append(cmd, "-c");
    //b_cmd_append(cmd, "-o", output_path);
    b_da_append_many(cmd, input_paths, input_paths_len);
    //libs(cmd);
    return b_cmd_run_sync(*cmd);
  }

  b_log(B_INFO, "%s is up-to-date", output_path);
  return true;
}

int
main(int argc, char *argv[])
{
  B_GO_REBUILD_URSELF(argc, argv);

  const char *program_name = b_shift_args(&argc, &argv);
  
  bool force = false;

  while (argc > 0) {
    const char *flag = b_shift_args(&argc, &argv);
    if (strcmp(flag, "-f") == 0) {
      force = true;
    } else {
      b_log(B_ERROR, "Unknown flag `%s`", flag);
      return 1;
    }
  }

  const char *cxx_dep_paths[] = {
    "src/vksetup.h",
  };
  const char* cxx_input_paths[] = {
    "src/cplusplus.cpp",
    "lib/imgui-1.90.7/imgui.cpp",
    "lib/imgui-1.90.7/imgui_demo.cpp",
    "lib/imgui-1.90.7/imgui_draw.cpp",
    "lib/imgui-1.90.7/imgui_tables.cpp",
    "lib/imgui-1.90.7/imgui_widgets.cpp",
    "lib/imgui-1.90.7/backends/imgui_impl_sdl2.cpp",
    "lib/imgui-1.90.7/backends/imgui_impl_vulkan.cpp",
  };
  
  const char *c_dep_paths[] = {
    "src/state.h",
    "src/vksetup.h",
  };
  const char* c_input_paths[] = {
    "src/render.c",
    "cplusplus.o",
    "imgui.o",
    "imgui_demo.o",
    "imgui_draw.o",
    "imgui_tables.o",
    "imgui_widgets.o",
    "imgui_impl_sdl2.o",
    "imgui_impl_vulkan.o",
  };

  B_Cmd cmd = {0};
  if (!compile_cxx(force, &cmd, cxx_input_paths, B_ARRAY_LEN(cxx_input_paths), cxx_dep_paths, B_ARRAY_LEN(c_dep_paths),"cplusplus.o")) return 1;
  if (!build_c(force, &cmd, c_input_paths, B_ARRAY_LEN(c_input_paths), c_dep_paths, B_ARRAY_LEN(c_dep_paths),"render")) return 1;

  return 0;
}

/*
  1. Build list of <object>.cpp (with <dep>s) -> into build/cxx/<object>/<dep>.o
  2. Build list of <object>.c (with <dep>s)   -> into build/c/<object>/<dep>.o

  3. Build <target>.c linking with the objects from 1 & 2 -> into <target>

  Check for rebuilds:
    1. <object.cpp> and <dep>s
    2. <object.c> and <dep>s
    3. <target.c> and all links {cxx,c}/ * / *.o

*/