#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Copyright 2020 The SkyWater PDK Authors.
#
# Use of this source code is governed by the Apache 2.0
# license that can be found in the LICENSE file or at
# https://www.apache.org/licenses/LICENSE-2.0
#
# SPDX-License-Identifier: Apache-2.0

import os

from dataclasses import dataclass
from enum import Enum
from typing import Optional


def parse_filename(pathname):
    """Extract library and module name from pathname.

    >>> t = list(parse_filename('sky130_fd_io__top_ground_padonlyv2__tt_1p80V_3p30V_3p30V_25C.wrap.lib'))
    >>> t.pop(0)
    Cell(name='top_ground_padonlyv2', library=Library(node=LibraryNode.SKY130, source=LibrarySource('fd'), type=LibraryType.io, name=None, version=None))
    >>> t.pop(0)
    'tt_1p80V_3p30V_3p30V_25C'
    >>> t.pop(0)
    'wrap.lib'
    >>> t = list(parse_filename('v0.10.0/sky130_fd_sc_hdll__a211o__tt_1p80V_3p30V_3p30V_25C.wrap.json'))
    >>> t.pop(0)
    Cell(name='a211o', library=Library(node=LibraryNode.SKY130, source=LibrarySource('fd'), type=LibraryType.sc, name='hdll', version=LibraryVersion(milestone=0, major=10, minor=0, commits=0, hash='')))
    >>> t.pop(0)
    'tt_1p80V_3p30V_3p30V_25C'
    >>> t.pop(0)
    'wrap.json'

    >>> t = list(parse_filename('sky130_fd_io/v0.1.0/sky130_fd_io__top_powerhv_hvc_wpad__tt_1p80V_3p30V_100C.wrap.json'))
    >>> t.pop(0)
    Cell(name='top_powerhv_hvc_wpad', library=Library(node=LibraryNode.SKY130, source=LibrarySource('fd'), type=LibraryType.io, name=None, version=LibraryVersion(milestone=0, major=1, minor=0, commits=0, hash='')))
    >>> from skywater_pdk.corners import parse_filename as pf_corners
    >>> pf_corners(t.pop(0))
    Corner(volts=[1.8, 3.3], temps=[100], flags=[], types=[CornerType.t, CornerType.t])
    >>> t.pop(0)
    'wrap.json'

    >>> parse_filename('libraries/sky130_fd_io/v0.2.1/cells/analog_pad/sky130_fd_io-analog_pad.blackbox.v')[0]
    Library(node=LibraryNode.SKY130, source=LibrarySource('fd'), type=LibraryType.io, name=None, version=LibraryVersion(milestone=0, major=2, minor=1, commits=0, hash=''))

    """
    dirname, filename = os.path.split(pathname)

    # Extract a version if it exists.
    dirbase, dirversion = os.path.split(dirname)
    if dirbase.endswith('/cells'):
        dirbase, dirversion = os.path.split(dirbase)
        assert dirversion == 'cells', (dirbase, dirversion)
        dirbase, dirversion = os.path.split(dirbase)
    try:
        version = LibraryVersion.parse(dirversion)
    except TypeError:
        version = None

    # Extract the file extension
    if '.' in filename:
        basename, extension = filename.split('.', 1)
    else:
        basename = filename
        extension = ''

    basename = basename.replace('-', SEPERATOR) # FIXME: !!!

    # Parse the actual filename
    bits = basename.split(SEPERATOR, 3)
    if len(bits) in (1, 2):
        library = Library.parse(bits.pop(0))
        extra = ""
        if bits:
            extra = bits.pop(0)
        if version:
            library.version = version
    elif len(bits) == 3:
        library = Cell.parse(bits[0]+SEPERATOR+bits[1])
        if version:
            library.library.version = version
        extra = bits[2]
    else:
        raise NotImplementedError()

    return (library, extra, extension)


SEPERATOR = "__"


@dataclass(order=True, frozen=True)
class LibraryVersion:
    """

    >>> v0 = LibraryVersion.parse("v0.0.0")
    >>> v0
    LibraryVersion(milestone=0, major=0, minor=0, commits=0, hash='')
    >>> v1a = LibraryVersion.parse("v0.0.0-10-g123abc")
    >>> v1a
    LibraryVersion(milestone=0, major=0, minor=0, commits=10, hash='123abc')
    >>> v1b = LibraryVersion.parse("v0.0.0-4-g123abc")
    >>> v1b
    LibraryVersion(milestone=0, major=0, minor=0, commits=4, hash='123abc')
    >>> v2 = LibraryVersion.parse("v0.0.2")
    >>> v2
    LibraryVersion(milestone=0, major=0, minor=2, commits=0, hash='')
    >>> v3 = LibraryVersion.parse("v0.2.0")
    >>> v3
    LibraryVersion(milestone=0, major=2, minor=0, commits=0, hash='')
    >>> v4 = LibraryVersion.parse("v0.0.10")
    >>> v4
    LibraryVersion(milestone=0, major=0, minor=10, commits=0, hash='')
    >>> v0 < v1a
    True
    >>> v1a < v2
    True
    >>> v0 < v2
    True
    >>> l = [v1a, v2, v3, v1b, v0, v2]
    >>> l.sort()
    >>> [i.fullname for i in l]
    ['0.0.0', '0.0.0-4-g123abc', '0.0.0-10-g123abc', '0.0.2', '0.0.2', '0.2.0']
    """
    milestone: int = 0
    major: int = 0
    minor: int = 0

    commits: Optional[int] = 0
    hash: Optional[str] = ''

    @classmethod
    def parse(cls, s):
        if not s.startswith('v'):
            raise TypeError("Unknown version: {}".format(s))
        kw = {}
        if '-' in s:
            git_bits = s.split('-')
            if len(git_bits) != 3:
                raise TypeError("Unparsable git version: {}".format(s))
            s = git_bits[0]
            kw['commits'] = int(git_bits[1])
            assert git_bits[2].startswith('g'), git_bits[2]
            kw['hash'] = git_bits[2][1:]
        kw['milestone'], kw['major'], kw['minor'] = (
            int(i) for i in s[1:].split('.'))
        return cls(**kw)

    def as_tuple(self):
        return (self.milestone, self.major, self.minor, self.commits, minor)

    @property
    def fullname(self):
        o = []
        s = "{}.{}.{}".format(
            self.milestone, self.major, self.minor)
        if self.commits:
            s += "-{}-g{}".format(self.commits, self.hash)
        return s


class LibraryNode(Enum):
    SKY130 = "SkyWater 130nm"

    @classmethod
    def parse(cls, s):
        s = s.upper()
        if not hasattr(cls, s):
            raise ValueError("Unknown node: {}".format(s))
        return getattr(cls, s)

    def __repr__(self):
        return "LibraryNode."+self.name


class LibrarySource(str):
    """Where a library was created."""
    Known = []

    @classmethod
    def parse(cls, s):
        try:
            return cls.Known[cls.Known.index(s)]
        except ValueError:
            return cls(s)

    @property
    def fullname(self):
        if self in self.Known:
            return self.__doc__
        else:
            return 'Unknown source: '+str.__repr__(self)

    def __repr__(self):
        return 'LibrarySource({})'.format(str.__repr__(self))


Foundary = LibrarySource("fd")
Foundary.__doc__ = "The SkyWater Foundary"
LibrarySource.Known.append(Foundary)

Efabless = LibrarySource("ef")
Efabless.__doc__ = "Efabless"
LibrarySource.Known.append(Efabless)

OSU = LibrarySource("osu")
OSU.__doc__ = "Oklahoma State University"
LibrarySource.Known.append(OSU)


class LibraryType(Enum):
    pr = "Primitives"
    sc = "Standard Cells"
    sp = "Build Space (Flash, SRAM, etc)"
    io = "IO and Periphery"
    xx = "Miscellaneous"

    @classmethod
    def parse(cls, s):
        if not hasattr(cls, s):
            raise ValueError("Unknown library type: {}".format(s))
        return getattr(cls, s)

    def __repr__(self):
        return "LibraryType."+self.name

    def __str__(self):
        return self.value


@dataclass
class Library:
    """

    >>> l = Library.parse("sky130_fd_sc_hd")
    >>> l
    Library(node=LibraryNode.SKY130, source=LibrarySource('fd'), type=LibraryType.sc, name='hd', version=None)
    >>> l.fullname
    'sky130_fd_sc_hd'
    >>> l.source.fullname
    'The SkyWater Foundary'
    >>> print(l.type)
    Standard Cells

    >>> l = Library.parse("sky130_rrr_sc_hd")
    >>> l
    Library(node=LibraryNode.SKY130, source=LibrarySource('rrr'), type=LibraryType.sc, name='hd', version=None)
    >>> l.fullname
    'sky130_rrr_sc_hd'
    >>> l.source.fullname
    "Unknown source: 'rrr'"


    """

    node: LibraryNode
    source: LibrarySource
    type: LibraryType
    name: Optional[str] = None
    version: Optional[LibraryVersion] = None

    @property
    def fullname(self):
        output = []
        output.append(self.node.name.lower())
        output.append(self.source.lower())
        output.append(self.type.name)
        if self.name:
            output.append(self.name)
        return "_".join(output)

    @classmethod
    def parse(cls, s):
        if SEPERATOR in s:
            raise ValueError(
                "Found separator '__' in library name: {!r}".format(s))

        bits = s.split("_")
        if len(bits) < 3:
            raise ValueError(
                "Did not find enough parts in library name: {}".format(bits))

        kw = {}
        kw['node'] = LibraryNode.parse(bits.pop(0))
        kw['source'] = LibrarySource.parse(bits.pop(0))
        kw['type'] = LibraryType.parse(bits.pop(0))
        if bits:
            kw['name'] = bits.pop(0)
        return cls(**kw)


@dataclass
class Cell:
    """
    >>> c = Cell.parse("sky130_fd_sc_hd__abc")
    >>> c
    Cell(name='abc', library=Library(node=LibraryNode.SKY130, source=LibrarySource('fd'), type=LibraryType.sc, name='hd', version=None))
    >>> c.fullname
    'sky130_fd_sc_hd__abc'

    >>> c = Cell.parse("abc")
    >>> c
    Cell(name='abc', library=None)
    >>> c.fullname
    Traceback (most recent call last):
        ...
    ValueError: Can't get fullname for cell without a library! Cell(name='abc', library=None)
    """

    name: str
    library: Optional[Library] = None

    @property
    def fullname(self):
        if not self.library:
            raise ValueError(
                "Can't get fullname for cell without a library! {}".format(
                    self))
        return "{}__{}".format(self.library.fullname, self.name)

    @classmethod
    def parse(cls, s):
        kw = {}
        if SEPERATOR in s:
            library, s = s.split(SEPERATOR, 1)
            kw['library'] = Library.parse(library)
        kw['name'] = s
        return cls(**kw)


if __name__ == "__main__":
    import doctest
    doctest.testmod()