import os
import shutil
import re


def get_curly_brace_scope_end(string, start_pos):
    """Given a string and the position of an opening curly brace, find the
       position of the closing brace.
    """
    if string[start_pos] != "{":
        raise ValueError("string must have \"{\" at start pos")
    string_end = len(string)
    bracket_counter = 1
    start_pos += 1
    while start_pos < string_end:
        if string[start_pos] == "{":
            bracket_counter += 1
        elif string[start_pos] == "}":
            bracket_counter -= 1
            if bracket_counter == 0:
                return start_pos
        start_pos += 1
    return -1


def add_doxygen_group(path, group_name):
    """Add a Doxygen group to the file at 'path'.

       Namespaces cause all kinds of problems, and we need to ensure that if
       the classes in a source file are contained within a namespace then we
       also put the @weakgroup inside.
    """
    filename = os.path.basename(path)
    if filename.startswith("juce_") and filename.endswith(".h"):

        group_definition_start = ("\r\n/** @weakgroup "
                                  + group_name
                                  + "\r\n *  @{\r\n */\r\n")
        group_definition_end = "\r\n/** @}*/\r\n"

        with open(path, "r") as f:
            content = f.read()

        # Put the group definitions inside all namespaces.
        namespace_regex = re.compile(r"\s+namespace\s+\S+\s+{")
        match = namespace_regex.search(content)
        while (match is not None):
            namespace_end = get_curly_brace_scope_end(content, match.end() - 1)
            if namespace_end == -1:
                raise ValueError("error finding end of namespace "
                                 + match.group()
                                 + " in "
                                 + path)
            content = (content[:match.end()]
                       + group_definition_start
                       + content[match.end():namespace_end]
                       + group_definition_end
                       + content[namespace_end:])
            search_start = (namespace_end
                            + len(group_definition_start)
                            + len(group_definition_end))

            match = namespace_regex.search(content, search_start)

        with open(path, "w") as f:
            f.write(group_definition_start)
            f.write(content)
            f.write(group_definition_end)


###############################################################################

# Get the list of JUCE modules to include.
juce_modules = ("juce_audio_basics", "juce_audio_devices",
                "juce_blocks_basics", "juce_core", "juce_events")

# A temporary directory to hold our preprocessed source files.
build_directory = "build"

# Make sure we have a clean temporary directory.
try:
    shutil.rmtree(build_directory)
except OSError as e:
    if e.errno != 2:
        # An errno of 2 indicates that the directory does not exist, which is
        # fine!
        raise e

# Copy the JUCE modules to the temporary directory, and process the source
# files.
module_definitions = []
for module_name in juce_modules:

    # Copy the required modules.
    original_module_dir = os.path.join("..", "..", "..", "modules",
                                       module_name)
    module_path = os.path.join(build_directory, module_name)
    shutil.copytree(original_module_dir, module_path)

    # Parse the module header to get module information.
    module_header = os.path.join(module_path, module_name + ".h")
    with open(module_header, "r") as f:
        content = f.read()
    block_info_result = re.match(r".*BEGIN_JUCE_MODULE_DECLARATION"
                                 "(.*)"
                                 "END_JUCE_MODULE_DECLARATION.*",
                                 content,
                                 re.DOTALL)
    detail_lines = []
    for line in block_info_result.group(1).split("\n"):
        stripped_line = line.strip()
        if stripped_line:
            result = re.match(r"^.*?description:\s*(.*)$", stripped_line)
            if result:
                short_description = result.group(1)
            else:
                detail_lines.append(stripped_line)

    # The module header causes problems for Doxygen, so delete it.
    os.remove(module_header)

    # Create a Doxygen group definition for the module.
    module_definiton = []
    module_definiton.append("/** @defgroup {n} {n}".format(n=module_name))
    module_definiton.append("    {d}".format(d=short_description))
    module_definiton.append("")
    for line in detail_lines:
        module_definiton.append("    - {l}".format(l=line))
    module_definiton.append("")
    module_definiton.append("    @{")
    module_definiton.append("*/")

    # Create a list of internal directories we can use as subgroups and create
    # the Doxygen group hierarchy string.
    dir_contents = os.listdir(module_path)
    subdirs = [x for x in dir_contents
               if os.path.isdir(os.path.join(module_path, x))]
    module_groups = {}
    for subdir in subdirs:
        subgroup_name = "{n}-{s}".format(n=module_name, s=subdir)
        module_groups[subgroup_name] = os.path.join(module_path, subdir)
        module_definiton.append("")
        module_definiton.append(
            "/** @defgroup {tag} {n} */".format(tag=subgroup_name, n=subdir)
        )
    module_definiton.append("")
    module_definiton.append("/** @} */")

    module_definitions.append("\r\n".join(module_definiton))

    # Put the top level files into the main group.
    for filename in (set(dir_contents) - set(subdirs)):
        add_doxygen_group(os.path.join(module_path, filename), module_name)

    # Put subdirectory files into their respective groups.
    for group_name in module_groups:
        for dirpath, dirnames, filenames in os.walk(module_groups[group_name]):
            for filename in filenames:
                add_doxygen_group(os.path.join(dirpath, filename), group_name)

# Create an extra header file containing the module hierarchy.
with open(os.path.join(build_directory, "juce_modules.dox"), "w") as f:
    f.write("\r\n\r\n".join(module_definitions))