from json import loads
from re import sub
from textwrap import dedent

from . import hints


def dump_scalar(entry: hints.JSONDataScalar) -> str:
    match entry:
        case None:
            return "null\n"
        case True:
            return "true\n"
        case False:
            return "false\n"
        case _:
            return f"{entry}\n"


def dump(obj: hints.JSONDataMap) -> str:
    ret = ""
    for key, value in obj.items():
        ret += key
        ret += ":"

        match value:
            case []:
                ret += " []\n"
            case {}:
                ret += " {}\n"
            case "":
                ret += ' ""\n'
            case list() as entries:
                ret += "\n"
                for entry in entries:
                    match entry:
                        case dict():
                            subdump = dump(entry)
                            ret += "\n".join("  " + l for l in subdump.splitlines())
                        case list():
                            pass
                        case _:
                            ret += f"  - {dump_scalar(entry)}"
            case dict() as substruct:
                ret += "\n"
                subdump = dump(substruct)
                ret += "\n".join("  " + l for l in subdump.splitlines()) + "\n"

            case str() as mlstring if key == "markdown_content":
                if mlstring.strip() == "" or dump_scalar(mlstring).strip() == "null":
                    ret += ' ""\n'
                else:
                    indented = "\n".join(("  " + l) for l in dump_scalar(mlstring).splitlines())
                    ret += f" >\n{indented}\n"
            case entry:
                ret += f" {dump_scalar(entry)}"

    return ret


def load(content: str) -> hints.JSONData:
    """parse subset of yaml into ``JSONData``

    >>> from pprint import pprint
    >>> yaml = '''
    ...     key1: str
    ...     key2: "str"
    ...     key3: 1
    ...     key4: 2.3
    ...     key5: 2e12
    ...     key6: null
    ...     key7: true
    ...     key8: false
    ...     key9:
    ...       - 1
    ...       - 23.2
    ...     key10:
    ...       - str
    ...       - "str"
    ...     key11: >
    ...       * a
    ...       * b:
    ...           * c
    ... '''
    >>> yaml_parsed = load(yaml)
    >>> compare = {
    ...     'key1': 'str',
    ...     'key2': 'str',
    ...     'key3': 1,
    ...     'key4': 2.3,
    ...     'key5': 2e12,
    ...     'key6': None,
    ...     'key7': True,
    ...     'key8': False,
    ...     'key9': [1, 23.2],
    ...     'key10': ['str', 'str'],
    ...     'key11': "* a\\n* b:\\n    * c",
    ... }
    >>> {k: yaml_parsed.get(k, None) for k in compare if compare[k] != yaml_parsed[k]}
    {}
    """

    ret = {}
    key = None
    value = None
    mlstring = False
    for line in sub(r"(:( >)?)[\s\n]*", r"\1\n  ", dedent(content).strip()).splitlines():
        if line.startswith("#") or line.strip() == "---":
            continue
        elif line.endswith(":"):
            if key:
                ret[key] = value
                value = None
            mlstring = False

            key = line.removesuffix(":")
        elif line.endswith(": >"):
            if key:
                ret[key] = value
                value = None
            mlstring = True

            key = line.removesuffix(": >")
        elif line.startswith("  -") and not mlstring:
            value = value or []
            try:
                parsed = loads(line.removeprefix("  -").strip())
            except:
                parsed = loads('"' + line.removeprefix("  -").strip() + '"')
            value.append(parsed)
        elif line.startswith("  ") and mlstring:
            value = value or ""
            value += line.removeprefix("  ") + "\n"
        else:
            try:
                value = loads(line.strip())
            except:
                value = loads('"' + line.strip() + '"')
    if key:
        ret[key] = value
        value = None

    return ret


if __name__ == "__main__":
    import doctest

    doctest.testmod()