#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# 
# Copyright 2019-2021 SkyWater PDK Authors
#
# 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
#
#     https://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.
#
# This code is *alternatively* available under a BSD-3-Clause license, see
# details in the README.md at the top level and the license text at
# https://github.com/google/skywater-pdk-libs-sky130_bag3_pr/blob/master/LICENSE.alternative
#
# SPDX-License-Identifier: BSD-3-Clause OR Apache 2.0

from typing import Any, Optional, List, Tuple, Sequence, Mapping

from pybag.enum import Orient2D
from pybag.core import BBox

from bag.util.immutable import ImmutableSortedDict, Param
from bag.layout.routing.grid import TrackSpec
from bag.layout.tech import TechInfo

from xbase.layout.data import LayoutInfo, LayoutInfoBuilder, CornerLayInfo, ViaInfo
from xbase.layout.array.data import ArrayLayInfo, ArrayEndInfo
from xbase.layout.res.tech import ResTech


class ResTechSkywater130(ResTech):
    """Resistor class for SkyWater130
    """
    def __init__(self, tech_info: TechInfo, metal: bool = False) -> None:
        ResTech.__init__(self, tech_info, metal=metal)
        if metal:
            raise RuntimeError("Metal resistors currently not supported")

    def get_width(self, **kwargs) -> int:
        if "unit_specs" not in kwargs:
            raise RuntimeError("Please add unit_specs")
        w_unit: int = kwargs['unit_specs']['params']['w']
        w_min: int = self._res_config['w_min']
        if w_unit < w_min:
            raise ValueError(f'w={w_unit} has to be greater than or equal to w_min={w_min}.')
        return w_unit

    def get_length(self, **kwargs) -> int:
        if "unit_specs" not in kwargs:
            raise RuntimeError("Please add unit_specs")
        l_unit: int = kwargs['unit_specs']['params']['l']
        l_min: int = self._res_config['l_min']
        if l_unit < l_min:
            raise ValueError(f'l={l_unit} has to be greater than or equal to l_min={l_min}.')
        return l_unit

    @property
    def min_size(self) -> Tuple[int, int]:
        return self._res_config['min_size']

    @property
    def blk_pitch(self) -> Tuple[int, int]:
        return self._res_config['blk_pitch']

    def get_track_specs(self, conn_layer: int, top_layer: int) -> List[TrackSpec]:
        grid_info: Sequence[Tuple[int, int, int]] = self._res_config['grid_info']

        return [TrackSpec(layer=lay, direction=Orient2D.y, width=vm_w, space=vm_sp, offset=(vm_w + vm_sp) // 2)
                for lay, vm_w, vm_sp in grid_info if conn_layer < lay <= top_layer]

    def get_edge_width(self, info: ImmutableSortedDict[str, Any], arr_dim: int, blk_pitch: int) -> int:
        edge_margin: int = self._res_config['edge_margin']
        return -(- edge_margin // blk_pitch) * blk_pitch

    def get_end_height(self, info: ImmutableSortedDict[str, Any], arr_dim: int, blk_pitch: int) -> int:
        end_margin: int = self._res_config['end_margin']
        return -(- end_margin // blk_pitch) * blk_pitch

    def get_blk_info(self, conn_layer: int, w: int, h: int, nx: int, ny: int, **kwargs: Any) -> Optional[ArrayLayInfo]:
        po_id_exty: int = self._res_config['po_id_exty']
        npc_po_enc: int = self._res_config['npc_po_enc']
        imp_npc_enc: Tuple[int, int] = self._res_config['imp_npc_enc']
        tap_imp_h: int = self._res_config['tap_imp_h']
        rlay_npc_enc: int = self._res_config['rlay_npc_enc']
        npc_sp: int = self._res_config['npc_sp']

        tap_imp_h2 = tap_imp_h // 2

        # unit resistor dimensions
        w_unit = self.get_width(**kwargs)
        l_unit = self.get_length(**kwargs)

        w_pitch, h_pitch = self.blk_pitch
        w_blk = -(-(w_unit + 2 * (npc_po_enc + max(rlay_npc_enc, npc_sp // 2))) // w_pitch) * w_pitch
        h_blk = -(-(l_unit + 2 * (po_id_exty + npc_po_enc + imp_npc_enc[1] + tap_imp_h2)) // h_pitch) * h_pitch
        if w < w_blk or h < h_blk:
            return None

        res_lay_table = self._tech_info.config['res_lay_table']

        # --- Compute layout --- #
        top_bbox = BBox(0, 0, w, h)
        builder = LayoutInfoBuilder()

        # draw ID layer in the center
        w2 = w // 2
        h2 = h // 2
        w_unit2 = w_unit // 2
        l_unit2 = l_unit // 2
        id_lp = res_lay_table['ID']
        builder.add_rect_arr(id_lp, BBox(w2 - w_unit2, h2 - l_unit2, w2 + w_unit2, h2 + l_unit2))

        # draw cut layer
        cut_lp = res_lay_table['CUT']
        builder.add_rect_arr(cut_lp, BBox(w2 - w_unit2, h2, w2 + w_unit2, h2 + 1))

        # draw poly: same width as ID layer, height extends beyond ID layer
        po_lp = res_lay_table['PO']
        builder.add_rect_arr(po_lp, BBox(w2 - w_unit2, h2 - l_unit2 - po_id_exty,
                                         w2 + w_unit2, h2 + l_unit2 + po_id_exty))

        # draw npc enclosing poly
        npc_lp = res_lay_table['NPC']
        builder.add_rect_arr(npc_lp, BBox(w2 - w_unit2 - npc_po_enc, h2 - l_unit2 - po_id_exty - npc_po_enc,
                                          w2 + w_unit2 + npc_po_enc, h2 + l_unit2 + po_id_exty + npc_po_enc))

        # draw resistor layer: span entire width, extend beyond npc in height
        res_type: str = kwargs['unit_specs']['params']['res_type']
        r_lp = self._res_config['rlay'][res_type]
        builder.add_rect_arr(r_lp, BBox(0, h2 - l_unit2 - po_id_exty - npc_po_enc - rlay_npc_enc,
                                        w, h2 + l_unit2 + po_id_exty + npc_po_enc + rlay_npc_enc))

        # draw implant layer extending beyond taps on top and bottom
        imp_lp = res_lay_table['IMP']
        builder.add_rect_arr(imp_lp, BBox(0, - tap_imp_h2, w, h + tap_imp_h2))

        # add bottom tap
        tap_h: int = self._res_config['tap_h']
        tap_h2 = tap_h // 2
        od_lp = res_lay_table['OD_sub']
        tap_via_specs: Mapping[str, Any] = self._res_config['tap_via_specs']
        tap_via_name: str = tap_via_specs['name']
        tap_via_w, tap_via_h = tap_via_specs['dim']
        tap_via_bot_enc: Tuple[int, int] = tap_via_specs['bot_enc']
        tap_via_top_enc: Tuple[int, int] = tap_via_specs['top_enc']
        tap_via_spx: int = tap_via_specs['spx']
        tap_via_benc = (tap_via_bot_enc[0], tap_via_bot_enc[0], tap_via_bot_enc[1], tap_via_bot_enc[1])
        tap_via_tenc = (tap_via_top_enc[0], tap_via_top_enc[0], tap_via_top_enc[1], tap_via_top_enc[1])
        tap_vnx = (w_unit - 2 * tap_via_bot_enc[0] + tap_via_spx) // (tap_via_w + tap_via_spx)
        tap_via_tot_w = tap_via_w * tap_vnx + tap_via_spx * (tap_vnx - 1)
        builder.add_rect_arr(od_lp, BBox(w2 - w_unit2, - tap_h2, w2 + w_unit2, tap_h2))
        builder.add_via(ViaInfo(tap_via_name, w2, 0, tap_via_w, tap_via_h, tap_via_benc, tap_via_tenc, tap_vnx, 1,
                                tap_via_spx))

        # add top tap
        builder.add_rect_arr(od_lp, BBox(w2 - w_unit2, h - tap_h2, w2 + w_unit2, h + tap_h2))
        builder.add_via(ViaInfo(tap_via_name, w2, h, tap_via_w, tap_via_h, tap_via_benc, tap_via_tenc, tap_vnx, 1,
                                tap_via_spx))

        # vias to conn_layer ports
        po_via_specs: Mapping[str, Any] = self._res_config['po_via_specs']
        po_via_name: str = po_via_specs['name']
        po_via_w, po_via_h = po_via_specs['dim']
        po_via_bot_enc: Tuple[int, int] = po_via_specs['bot_enc']
        po_via_top_enc: Tuple[int, int] = po_via_specs['top_enc']
        po_via_spx: int = po_via_specs['spx']
        po_via_benc = (po_via_bot_enc[0], po_via_bot_enc[0], po_via_bot_enc[1], po_via_bot_enc[1])
        po_via_tenc = (po_via_top_enc[0], po_via_top_enc[0], po_via_top_enc[1], po_via_top_enc[1])
        po_vnx = (w_unit - 2 * po_via_bot_enc[0] + po_via_spx) // (po_via_w + po_via_spx)
        po_via_tot_w = po_via_w * po_vnx + po_via_spx * (po_vnx - 1)
        builder.add_via(ViaInfo(po_via_name, w2, h2 - l_unit2 - po_via_h // 2, po_via_w, po_via_h, po_via_benc,
                                po_via_tenc, po_vnx, 1, po_via_spx))
        builder.add_via(ViaInfo(po_via_name, w2, h2 + l_unit2 + po_via_h // 2, po_via_w, po_via_h, po_via_benc,
                                po_via_tenc, po_vnx, 1, po_via_spx))

        # ports on conn_layer
        conn_lp = self._tech_info.get_lay_purp_list(self.conn_layer)[0]
        minus_bbox = BBox(w2 - po_via_tot_w // 2 - po_via_top_enc[0], h2 - l_unit2 - po_via_h - po_via_top_enc[1],
                          w2 + po_via_tot_w // 2 + po_via_top_enc[0], h2 - l_unit2 + po_via_top_enc[1])
        builder.add_rect_arr(conn_lp, minus_bbox)

        plus_bbox = BBox(w2 - po_via_tot_w // 2 - po_via_top_enc[0], h2 + l_unit2 - po_via_top_enc[1],
                         w2 + po_via_tot_w // 2 + po_via_top_enc[0], h2 + l_unit2 + po_via_h + po_via_top_enc[1])
        builder.add_rect_arr(conn_lp, plus_bbox)

        tap_via_h2 = tap_via_h // 2
        tap_via_tot_w2 = tap_via_tot_w // 2
        bulk0_bbox = BBox(w2 - tap_via_tot_w2 - tap_via_top_enc[0], - tap_via_h2 - tap_via_top_enc[1],
                          w2 + tap_via_tot_w2 + tap_via_top_enc[0], tap_via_h2 + tap_via_top_enc[1])
        builder.add_rect_arr(conn_lp, bulk0_bbox)
        bulk1_bbox = BBox(w2 - tap_via_tot_w2 - tap_via_top_enc[0], h - tap_via_h2 - tap_via_top_enc[1],
                          w2 + tap_via_tot_w2 + tap_via_top_enc[0], h + tap_via_h2 + tap_via_top_enc[1])
        builder.add_rect_arr(conn_lp, bulk1_bbox)

        ports = dict(MINUS=[(conn_lp[0], [minus_bbox])], PLUS=[(conn_lp[0], [plus_bbox])],
                     BULK=[(conn_lp[0], [bulk0_bbox, bulk1_bbox])])

        lay_info = builder.get_info(top_bbox)
        edge_info = Param(dict(od_margin=0))
        end_info = Param(dict(od_margin=0))
        ports = Param(ports)
        return ArrayLayInfo(lay_info, ports, edge_info, end_info)

    # noinspection PyMethodMayBeStatic
    def get_edge_info(self, w: int, h: int, info: ImmutableSortedDict[str, Any], **kwargs: Any) -> LayoutInfo:
        builder = LayoutInfoBuilder()
        blk_bbox = BBox(0, 0, w, h)
        return builder.get_info(blk_bbox)

    # noinspection PyMethodMayBeStatic
    def get_end_info(self, w: int, h: int, info: ImmutableSortedDict[str, Any], **kwargs: Any) -> ArrayEndInfo:
        builder = LayoutInfoBuilder()
        blk_bbox = BBox(0, 0, w, h)
        return ArrayEndInfo(builder.get_info(blk_bbox), ImmutableSortedDict())

    # noinspection PyMethodMayBeStatic
    def get_corner_info(self, w: int, h: int, info: ImmutableSortedDict[str, Any], **kwargs: Any) -> CornerLayInfo:
        x_margins = dict(well=0, base=0)
        y_margins = dict(well=0, base=0)
        edgel = Param(dict(margins=x_margins))
        edgeb = Param(dict(margins=y_margins))
        builder = LayoutInfoBuilder()
        blk_bbox = BBox(0, 0, w, h)
        return CornerLayInfo(builder.get_info(blk_bbox), (0, 0), edgel, edgeb)