import os
import subprocess

PROG_BIN_DIR = "bin"
PROG_SRC_DIR = "src"
LIB_BIN_DIR = "bin/libs"
LIB_SRC_DIR = "src/libs"


class BinBuilder:
  def __init__(self, flavor, debug=False, auto_build=False):
    if flavor == 'none':
      flavor = None
    self.flavor = flavor
    self.debug = debug
    self.auto_build = auto_build

  def make_prog(self, prog_name):
    return self.make_progs([prog_name])[0]

  def make_progs(self, prog_names):
    bins = {}
    for p in prog_names:
      bin_path = os.path.join(PROG_BIN_DIR, p + '_' + self.flavor)
      if self.debug:
        bin_path = bin_path + "_dbg"
      src_path = os.path.join(PROG_SRC_DIR, p + '.c')
      bins[bin_path] = src_path
    return self._build_bins(bins)

  def make_lib(self, lib_name):
    return self.make_libs([lib_name])[0]

  def make_libs(self, lib_names):
    bins = {}
    for name in lib_names:
      lib_name = name
      lib_bin_dir = LIB_BIN_DIR
      if self.flavor is not None:
        lib_bin_dir += "-" + self.flavor
      lib_name += ".library"
      bin_path = os.path.join(lib_bin_dir, lib_name)
      src_path = os.path.join(LIB_SRC_DIR, name + '.c')
      bins[bin_path] = src_path
    return self._build_bins(bins)

  def _build_bins(self, bin_paths):
    # check sources
    all_bins = []
    rebuild_bins = []
    for binp in bin_paths:
      all_bins.append(binp)
      srcp = bin_paths[binp]
      if not os.path.exists(srcp):
        raise ValueError("source does not exist: '%s'" % srcp)
      # if bin already exits check if its never
      if os.path.exists(binp):
        srct = os.path.getmtime(srcp)
        bint = os.path.getmtime(binp)
        # allow 10s delta
        if bint + 10 <= srct:
          rebuild_bins.append(binp)
      else:
        rebuild_bins.append(binp)
        # create bin dir if its mising
        bin_dir = os.path.dirname(binp)
        if not os.path.exists(bin_dir):
          os.makedirs(bin_dir)
    # call make to rebuild bins
    if len(rebuild_bins) > 0:
      info = " ".join(rebuild_bins)
      if self.auto_build:
        print("BinBuilder: making", info)
        args = ['make']
        args += rebuild_bins
        subprocess.check_call(args, stdout=subprocess.PIPE)
      else:
        raise RuntimeError("Rebuild needed for: " + info)
    return all_bins