#! /usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>
# Copyright 2022 Jan Götte <code@jaseg.de>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

import os
import re
import warnings
import copy
from collections import namedtuple
from pathlib import Path

from .excellon import ExcellonFile, parse_allegro_ncparam, parse_allegro_logfile
from .rs274x import GerberFile
from .ipc356 import Netlist
from .cam import FileSettings
from .layer_rules import MATCH_RULES


STANDARD_LAYERS = [
        'mechanical outline',
        'top copper',
        'top mask',
        'top silk',
        'top paste',
        'bottom copper',
        'bottom mask',
        'bottom silk',
        'bottom paste',
        ]

class NamingScheme:
    kicad = {
    'top copper':           '{board_name}-F.Cu.gbr',
    'top mask':             '{board_name}-F.Mask.gbr',
    'top silk':             '{board_name}-F.SilkS.gbr',
    'top paste':            '{board_name}-F.Paste.gbr',
    'bottom copper':        '{board_name}-B.Cu.gbr',
    'bottom mask':          '{board_name}-B.Mask.gbr',
    'bottom silk':          '{board_name}-B.SilkS.gbr',
    'bottom paste':         '{board_name}-B.Paste.gbr',
    'inner copper':         '{board_name}-In{layer_number}.Cu.gbr',
    'mechanical outline':   '{board_name}-Edge.Cuts.gbr',
    'drill unknown':        '{board_name}.drl',
    'other netlist':        '{board_name}.d356',
    }


def match_files(filenames):
    matches = {}
    for generator, rules in MATCH_RULES.items():
        gen = {}
        matches[generator] = gen
        for layer, regex in rules.items():
            for fn in filenames:
                if (m := re.fullmatch(regex, fn.name, re.IGNORECASE)):
                    if layer == 'inner copper':
                        target = 'inner_' + ''.join(e or '' for e in m.groups()) + ' copper'
                    else:
                        target = layer
                    gen[target] = gen.get(target, []) + [fn]
    return matches


def best_match(filenames):
    matches = match_files(filenames)
    matches = sorted(matches.items(), key=lambda pair: len(pair[1]))
    generator, files = matches[-1]
    return generator, files


def identify_file(data):
    if 'M48' in data:
        return 'excellon'

    if 'G90' in data and ';LEADER:' in data: # yet another allegro special case
        return 'excellon'

    if 'FSLAX' in data or 'FSTAX' in data:
        return 'gerber'

    if 'UNITS CUST' in data:
        return 'ipc356'

    return None


def common_prefix(l):
    out = []
    for cand in l:
        score = lambda n: sum(elem.startswith(cand[:n]) for elem in l)
        baseline = score(1)
        if len(l) - baseline > 5:
            continue
        for n in range(2, len(cand)):
            if len(l) - score(n) > 5:
                break
        out.append(cand[:n-1])
 
    if not out:
        return ''
 
    return sorted(out, key=len)[-1]

def autoguess(filenames):
    prefix = common_prefix([f.name for f in filenames])

    matches = {}
    for f in filenames:
        name = layername_autoguesser(f.name[len(prefix):] if f.name.startswith(prefix) else f.name)
        if name != 'unknown unknown':
            matches[name] = matches.get(name, []) + [f]

    inner_layers = [ m for m in matches if 'inner' in m ]
    if len(inner_layers) >= 2 and 'copper top' not in matches and 'copper bottom' not in matches:
        if 'inner_01 copper' in matches:
            warnings.warn('Could not find copper layer. Re-assigning outermost inner layers to top/bottom copper.')
            matches['top copper'] = matches.pop('inner_01 copper')
            last_inner = sorted(inner_layers, key=lambda name: int(name.partition(' ')[0].partition('_')[2]))[-1]
            matches['bottom copper'] = matches.pop(last_inner)

    return matches


def layername_autoguesser(fn):
    fn, _, ext = fn.lower().rpartition('.')
    
    if ext in ('log', 'err', 'fdl', 'py', 'sh', 'md', 'rst', 'zip', 'pdf', 'svg', 'ps', 'png', 'jpg', 'bmp'):
        return 'unknown unknown'

    side, use = 'unknown', 'unknown'
    if re.search('top|front|pri?m?(ary)?', fn):
        side = 'top'
        use = 'copper'

    if re.search('bot(tom)?|back|sec(ondary)?', fn):
        side = 'bottom'
        use = 'copper'

    if re.search('silks?(creen)?|symbol', fn):
        use = 'silk'

    elif re.search('(solder)?paste|metalmask', fn):
        use = 'paste'

    elif re.search('(solder)?(mask|resist)', fn):
        use = 'mask'

    elif re.search('drill|rout?e?', fn):
        use = 'drill'
        side = 'unknown'

        if re.search(r'np(th|lt)?|(non|un)\W*plated|(non|un)\Wgalv', fn):
            side = 'nonplated'

        elif re.search('pth|plated|galv|plt', fn):
            side = 'plated'

    elif (m := re.search(r'(la?y?e?r?|in(ner)?|conduct(or|ive)?)\W*(?P<num>[0-9]+)', fn)):
        use = 'copper'
        side = f'inner_{int(m["num"]):02d}'

    elif re.search('film', fn):
        use = 'copper'

    elif re.search('out(line)?', fn):
        use = 'outline'
        side = 'mechanical'

    elif 'ipc' in fn and '356' in fn:
        use = 'netlist'
        side = 'other'

    elif 'netlist' in fn:
        use = 'netlist'
        side = 'other'

    if side == 'unknown':
        if re.search(r'[^a-z0-9]a', fn):
            side = 'top'
        elif re.search(r'[^a-z0-9]b', fn):
            side = 'bottom'

    return f'{side} {use}'


class LayerStack:

    def __init__(self, graphic_layers, drill_layers, netlist=None, board_name=None):
        self.graphic_layers = graphic_layers
        self.drill_layers = drill_layers
        self.board_name = board_name
        self.netlist = netlist

    @classmethod
    def from_directory(kls, directory, board_name=None):

        directory = Path(directory)
        if not directory.is_dir():
            raise FileNotFoundError(f'{directory} is not a directory')

        files = [ path for path in directory.glob('**/*') if path.is_file() ]
        generator, filemap = best_match(files)

        if sum(len(files) for files in filemap.values()) < 6:
            warnings.warn('Ambiguous gerber filenames. Trying last-resort autoguesser.')
            generator = None
            filemap = autoguess(files)
            if len(filemap) < 6:
                raise ValueError('Cannot figure out gerber file mapping. Partial map is: ', filemap)

        excellon_settings, external_tools = None, None
        if generator == 'geda':
            # geda is written by geniuses who waste no bytes of unnecessary output so it doesn't actually include the
            # number format in files that use imperial units. Unfortunately it also doesn't include any hints that the
            # file was generated by geda, so we have to guess by context whether this is just geda being geda or
            # potential user error.
            excellon_settings = FileSettings(number_format=(2, 4))

        elif generator == 'allegro':
            # Allegro puts information that is absolutely vital for parsing its excellon files... into another file,
            # next to the actual excellon file. Despite pretty much everyone else having figured out a way to put that
            # info into the excellon file itself, even if only as a comment.
            if 'excellon params' in filemap:
                excellon_settings = parse_allegro_ncparam(filemap['excellon params'][0].read_text())
                for file in filemap['excellon params']:
                    if (external_tools := parse_allegro_logfile(file.read_text())):
                        break
                del filemap['excellon params']
            # Ignore if we can't find the param file -- maybe the user has convinced Allegro to actually put this
            # information into a comment, or maybe they have made Allegro just use decimal points like XNC does.

            filemap = autoguess([ f for files in filemap.values() for f in files ])
            if len(filemap) < 6:
                raise SystemError('Cannot figure out gerber file mapping')
            # FIXME use layer metadata from comments and ipc file if available

        elif generator == 'zuken':
            filemap = autoguess([ f for files in filemap.values() for f in files ])
            if len(filemap) < 6:
                raise SystemError('Cannot figure out gerber file mapping')
            # FIXME use layer metadata from comments and ipc file if available

        elif generator == 'altium':
            if 'mechanical outline' in filemap:
                # Use lowest-numbered mechanical layer as outline, ignore others.
                mechs = {}
                for layer in filemap['mechanical outline']:
                    if layer.name.lower().endswith('gko'):
                        filemap['mechanical outline'] = [layer]
                        break

                    if (m := re.match(r'.*\.gm([0-9]+)', layer.name, re.IGNORECASE)):
                        mechs[int(m[1])] = layer
                    else:
                        break
                else:
                    filemap['mechanical outline'] = [sorted(mechs.items(), key=lambda x: x[0])[0][1]]

        else:
            excellon_settings = None

        ambiguous = [ f'{key} ({", ".join(x.name for x in value)})' for key, value in filemap.items() if len(value) > 1 and not 'drill' in key ]
        if ambiguous:
            raise SystemError(f'Ambiguous layer names: {", ".join(ambiguous)}')

        drill_layers = []
        netlist = None
        layers = {} # { tuple(key.split()): None for key in STANDARD_LAYERS }
        for key, paths in filemap.items():
            if len(paths) > 1 and not 'drill' in key:
                raise ValueError(f'Multiple matching files found for {key} layer: {", ".join(value)}')

            for path in paths:
                id_result = identify_file(path.read_text())

                if 'netlist' in key:
                    layer = Netlist.open(path)

                elif ('outline' in key or 'drill' in key) and id_result != 'gerber':
                    if id_result is None:
                        # Since e.g. altium uses ".txt" as the extension for its drill files, we have to assume the
                        # current file might not be a drill file after all.
                        continue

                    if 'nonplated' in key:
                        plated = False
                    elif 'plated' in key:
                        plated = True
                    else:
                        plated = None
                    layer = ExcellonFile.open(path, plated=plated, settings=excellon_settings, external_tools=external_tools)
                else:

                    layer = GerberFile.open(path)

                if key == 'mechanical outline':
                    layers['mechanical', 'outline'] = layer

                elif 'drill' in key:
                    drill_layers.append(layer)

                elif 'netlist' in key:
                    if netlist:
                        warnings.warn(f'Found multiple netlist files, using only first one. Have: {netlist.original_path.name}, got {path.name}')
                    else:
                        netlist = layer

                else:
                    side, _, use = key.partition(' ')
                    layers[(side, use)] = layer

                hints = set(layer.generator_hints) | { generator }
                if len(hints) > 1:
                    warnings.warn('File identification returned ambiguous results. Please raise an issue on the gerbonara '
                            'tracker and if possible please provide these input files for reference.')

        board_name = common_prefix([l.original_path.name for l in layers.values() if l is not None])
        board_name = re.sub(r'^\W+', '', board_name)
        board_name = re.sub(r'\W+$', '', board_name)
        return kls(layers, drill_layers, netlist, board_name=board_name)

    def save_to_directory(self, path, naming_scheme={}, overwrite_existing=True):
        outdir = Path(path)
        outdir.mkdir(parents=True, exist_ok=overwrite_existing)

        def check_not_exists(path):
            if path.exists() and not overwrite_existing:
                raise SystemError(f'Path exists but overwrite_existing is False: {path}')

        def get_name(layer_type, layer):
            nonlocal naming_scheme, overwrite_existing

            if (m := re.match('inner_([0-9]*) copper', layer_type)):
                layer_type = 'inner copper'
                num = int(m[1])
            else:
                num = None

            if layer_type in naming_scheme:
                path = outdir / naming_scheme[layer_type].format(layer_num=num, board_name=self.board_name)
            else:
                path = outdir / layer.original_path.name

            check_not_exists(path)
            return path

        for (side, use), layer in self.graphic_layers.items():
            outpath = get_name(f'{side} {use}', layer)
            layer.save(outpath)

        if naming_scheme:
            self.normalize_drill_layers()

            def save_layer(layer, layer_name):
                nonlocal self, outdir, drill_layers, check_not_exists
                path = outdir / drill_layers[layer_name].format(board_name=self.board_name)
                check_not_exists(path)
                layer.save(path)

            drill_layers = { key.partition()[2]: value for key, value in naming_scheme if 'drill' in key }
            if set(drill_layers) == {'plated', 'nonplated', 'unknown'}:
                save_layer(self.drill_pth, 'plated')
                save_layer(self.drill_npth, 'nonplated')
                save_layer(self.drill_unknown, 'unknown')

            elif 'plated' in drill_layers and len(drill_layers) == 2:
                save_layer(self.drill_pth, 'plated')
                merged = copy.copy(self.drill_npth)
                merged.merge(self.drill_unknown)
                save_layer(merged, list(set(drill_layers) - {'plated'})[0])

            elif 'unknown' in drill_layers:
                merged = copy.copy(self.drill_pth)
                merged.merge(self.drill_npth)
                merged.merge(self.drill_unknown)
                save_layer(merged, 'unknown')

            else:
                raise ValueError('Namin scheme does not specify unknown drill layer')

        else:
            for layer in self.drill_layers:
                outpath = outdir / layer.original_path.name
                check_not_exists(outpath)
                layer.save(outpath)

        if self.netlist:
            layer.save(get_name('other netlist', self.netlist))

    def __str__(self):
        names = [ f'{side} {use}' for side, use in self.graphic_layers ]
        return f'<LayerStack {self.board_name} [{", ".join(names)}] and {len(self.drill_layers)} drill layers>'

    def __repr__(self):
        return str(self)

    def merge_drill_layers(self):
        target = ExcellonFile(comments='Drill files merged by gerbonara')

        for layer in self.drill_layers:
            if isinstance(layer, GerberFile):
                layer = layer.to_excellon()

            target.merge(layer)

        self.drill_layers = [target]

    def normalize_drill_layers(self):
        # TODO: maybe also separate into drill and route?
        drill_pth, drill_npth, drill_aux = [], [], []

        for layer in self.drill_layers:
            if isinstance(layer, GerberFile):
                layer = layer.to_excellon()

            if layer.is_plated:
                drill_pth.append(layer)
            elif layer.is_nonplated:
                drill_pth.append(layer)
            else:
                drill_aux.append(layer)
        
        pth_out, *rest = drill_pth or [ExcellonFile()]
        for layer in rest:
            pth_out.merge(layer)

        npth_out, *rest = drill_npth or [ExcellonFile()]
        for layer in rest:
            npth_out.merge(layer)

        unknown_out = ExcellonFile()
        for layer in drill_aux:
            for obj in layer.objects:
                if obj.plated is None:
                    unknown_out.append(obj)
                elif obj.plated:
                    pth_out.append(obj)
                else:
                    npth_out.append(obj)

        self.drill_pth, self.drill_npth = pth_out, npth_out
        self.drill_unknown = unknown_out if unknown_out else None
        self._drill_layers = []

    @property
    def drill_layers(self):
        if self._drill_layers:
            return self._drill_layers
        if self.drill_pth or self.drill_npth or self.drill_unknown:
            return [self.drill_pth, self.drill_npth, self.drill_unknown]
        return []

    @drill_layers.setter
    def drill_layers(self, value):
        self._drill_layers = value
        self.drill_pth = self.drill_npth = self.drill_unknown = None

    def __len__(self):
        return len(self.layers)

    def get(self, index, default=None):
        if self.contains(key):
            return self[key]
        else:
            return default

    def __contains__(self, index):
        if isinstance(index, str):
            side, _, use = index.partition(' ')
            return (side, use) in self.layers

        elif isinstance(index, tuple):
            return index in self.graphic_layers

        return index < len(self.copper_layers)

    def __getitem__(self, index):
        if isinstance(index, str):
            side, _, use = index.partition(' ')
            return self.graphic_layers[(side, use)]

        elif isinstance(index, tuple):
            return self.graphic_layers[index]

        return self.copper_layers[index]

    @property
    def copper_layers(self):
        copper_layers = [ (key, layer) for key, layer in self.layers.items() if key.endswith('copper') ]

        def sort_layername(val):
            key, _layer = val
            if key.startswith('top'):
                return -1
            if key.startswith('bottom'):
                return 1e99
            assert key.startswith('inner_')
            return int(key[len('inner_'):])

        return [ layer for _key, layer in sorted(copper_layers, key=sort_layername) ]

    @property
    def top_side(self):
        return { key: self[key] for key in ('top copper', 'top mask', 'top silk', 'top paste', 'mechanical outline') }

    @property
    def bottom_side(self):
        return { key: self[key] for key in ('bottom copper', 'bottom mask', 'bottom silk', 'bottom paste', 'mechanical outline') }

    @property
    def outline(self):
        return self['mechanical outline']
    
    def _merge_layer(self, target, source):
        if source is None:
            return
        
        if self[target] is None:
            self[target] = source

        else:
            self[target].merge(source)

    def merge(self, other):
        all_keys = set(self.layers.keys()) | set(other.layers.keys())
        exclude = { key.split() for key in STANDARD_LAYERS }
        all_keys = { key for key in all_keys if key not in exclude }
        if all_keys:
            warnings.warn('Cannot merge unknown layer types: {" ".join(all_keys)}')

        for side in 'top', 'bottom':
            for use in 'copper', 'mask', 'silk', 'paste':
                self._merge_layer((side, use), other[side, use])

        our_inner, their_inner = self.copper_layers[1:-1], other.copper_layers[1:-1]

        if bool(our_inner) != bool(their_inner):
            warnings.warn('Merging board without inner layers into board with inner layers, inner layers will be empty on first board.')

        elif our_inner and their_inner:
            warnings.warn('Merging boards with different inner layer counts. Will fill inner layers starting at core.')

        diff = len(our_inner) - len(their_inner)
        their_inner = ([None] * max(0, diff//2)) + their_inner + ([None] * max(0, diff//2))
        our_inner = ([None] * max(0, -diff//2)) + their_inner + ([None] * max(0, -diff//2))

        new_inner = []
        for ours, theirs in zip(our_inner, their_inner):
            if ours is None:
                new_inner.append(theirs)
            elif theirs is None:
                new_inner.append(ours)
            else:
                ours.merge(theirs)
                new_inner.append(ours)

        for i, layer in enumerate(new_inner, start=1):
            self[f'inner_{i} copper'] = layer

        self._merge_layer('mechanical outline', other['mechanical outline'])

        self.normalize_drill_layers()
        other.normalize_drill_layers()

        self.drill_pth.merge(other.drill_pth)
        self.drill_npth.merge(other.drill_npth)
        self.drill_unknown.merge(other.drill_unknown)
        self.netlist.merge(other.netlist)

