from pathlib import Path
from typing import List, MutableMapping, Optional, Iterator, Union

from ee import EeException
from ee.money import Money
from ee.xml import types

__all__ = [
    "Part",
    "PartDb",
    "load_db",
    "save_db",
]


class Reference(object):
    pass

    def to_xml(self):
        return None


class PartReference(Reference):
    def __init__(self, uri: str):
        self.uri = uri

    def to_xml(self):
        return types.PartReference(part_uri=self.uri)


class SchematicReference(Reference):
    def __init__(self, reference: str):
        self.reference = reference

    def to_xml(self):
        return types.SchematicReference(reference=self.reference)


class PartNumber(Reference):
    def __init__(self, value: str):
        self.value = value

    def to_xml(self):
        return types.PartNumber(value=self.value)


class SupplierPartNumber(Reference):
    def __init__(self, value: str):
        self.value = value

    def to_xml(self):
        return types.SupplierPartNumber(value=self.value)


class ReferenceList(object):
    def __init__(self, part_uri):
        self.part_uri_ = part_uri
        self.part_references: List[PartReference] = []
        self.schematic_references: List[SchematicReference] = []
        self.mpns: List[PartNumber] = []
        self.spns: List[SupplierPartNumber] = []
        self.description_references: List[str] = []

    def to_xml(self):
        part_references = [r.to_xml() for r in self.part_references if isinstance(r, PartReference)]
        schematic_references = [r.to_xml() for r in self.schematic_references if isinstance(r, SchematicReference)]
        mpns = [r.to_xml() for r in self.mpns if isinstance(r, PartNumber)]
        spns = [r.to_xml() for r in self.spns if isinstance(r, SupplierPartNumber)]
        description_references = self.description_references

        if len(part_references) or len(schematic_references) or len(mpns) or len(spns) or \
                len(description_references):
            return types.ReferenceList(part_reference=part_references,
                                       schematic_reference=schematic_references,
                                       part_number=mpns,
                                       supplier_part_number=spns,
                                       description=description_references)

    # Part Reference

    def add_part_reference(self, uri):
        self.part_references.append(PartReference(uri))

    def get_exactly_one_part_reference(self) -> PartReference:
        refs = self.part_references
        if len(refs) == 0:
            raise EeException("This part does not contain any part references{}".
                              format(", uri=" + self.part_uri_ if self.part_uri_ else ""))
        if len(refs) != 1:
            raise EeException("This part does not contain exactly one part reference: {}".
                              format(", ".join([ref.uri for ref in refs])))

        return refs[0]

    # Schematic references

    def add_schematic_reference(self, ref):
        self.schematic_references.append(SchematicReference(reference=ref))

    def get_only_schematic_reference(self) -> Optional[SchematicReference]:
        return next(iter(self.schematic_references), None)

    def get_exactly_one_schematic_reference(self) -> SchematicReference:
        refs = self.schematic_references
        if len(refs) == 0:
            raise EeException("This part does not contain any schematic references{}".
                              format(", uri=" + self.part_uri_ if self.part_uri_ else ""))
        if len(refs) != 1:
            raise EeException("This part does not contain exactly one schematic reference: {}".
                              format(", ".join([ref.reference for ref in refs])))

        return refs[0]

    # MPNs

    def add_mpn(self, mpn: str):
        self.mpns.append(PartNumber(value=mpn))

    def get_only_mpn(self) -> Optional[PartNumber]:
        return next(iter(self.mpns), None)

    def get_exactly_one_mpn(self) -> PartNumber:
        mpns = self.mpns
        if len(mpns) == 0:
            raise EeException("This part does not contain any manufacturer part numbers{}".
                              format(", uri=" + self.part_uri_ if self.part_uri_ else ""))
        if len(mpns) != 1:
            raise EeException("This part does not contain exactly one mpn: {}".
                              format(", ".join([mpn.value for mpn in mpns])))

        return mpns[0]

    # SPNs

    def add_spn(self, mpn: str):
        self.spns.append(SupplierPartNumber(value=mpn))

    def get_only_spn(self) -> Optional[SupplierPartNumber]:
        return next(iter(self.spns), None)

    def get_exactly_one_spn(self) -> SupplierPartNumber:
        spns = self.spns
        if len(spns) == 0:
            raise EeException("This part does not contain any supplier part numbers{}".
                              format(", uri=" + self.part_uri_ if self.part_uri_ else ""))
        if len(spns) != 1:
            raise EeException("This part does not contain exactly one spn: {}".
                              format(", ".join([spn.value for spn in spns])))

        return spns[0]

    def add_description_reference(self, description: str):
        self.description_references.append(description)


# TODO: Replace self.xml.referencesProp with ReferenceList
class Part(object):
    def __init__(self, xml: types.Part):
        assert type(xml) == types.Part
        self.xml = xml
        xml.referencesProp = xml.referencesProp if xml.referencesProp is not None else types.ReferenceList()
        xml.price_breaksProp = xml.price_breaksProp if xml.price_breaksProp is not None else types.PriceBreakList()
        xml.linksProp = xml.linksProp if xml.linksProp is not None else types.LinkList()
        xml.factsProp = xml.factsProp if xml.factsProp is not None else types.FactList()

        self.facts = Facts(self)

    def clean_xml(self):
        x = self.xml
        if len(x.referencesProp.part_referenceProp) == 0 and \
                len(x.referencesProp.schematic_referenceProp) == 0 and \
                len(x.referencesProp.part_numberProp) == 0 and \
                len(x.referencesProp.supplier_part_numberProp) == 0:
            x.referencesProp = None
        if len(x.price_breaksProp.price_break) == 0:
            x.price_breaksProp = None
        if len(x.linksProp.link) == 0:
            x.linksProp = None
        if len(x.factsProp.fact) == 0:
            x.factsProp = None

    @property
    def underlying(self) -> types.Part:
        return self.xml

    @property
    def uri(self) -> str:
        return self.xml.uriProp

    @property
    def supplier(self) -> str:
        return self.xml.supplierProp

    # Part number ref

    def add_part_reference(self, uri):
        self.get_part_references().append(types.PartReference(part_uri=uri))

    def get_part_references(self) -> List[types.PartReference]:
        return self.xml.referencesProp.part_referenceProp

    def get_exactly_one_part_reference(self) -> types.PartReference:
        refs = self.get_part_references()
        if len(refs) == 0:
            raise EeException("This part does not contain any part references{}".
                              format(", uri=" + self.uri if self.uri else ""))
        if len(refs) != 1:
            raise EeException("This part does not contain exactly one part reference: {}".
                              format(", ".join([ref.part_uriProp for ref in refs])))

        return refs[0]

    # Schematic references

    def add_schematic_reference(self, ref):
        self.get_schematic_references().append(types.SchematicReference(reference=ref))

    def get_schematic_references(self) -> List[types.SchematicReference]:
        return self.xml.referencesProp.schematic_referenceProp

    def get_only_schematic_reference(self) -> Optional[types.SchematicReference]:
        return next(iter(self.get_schematic_references()), None)

    def get_exactly_one_schematic_reference(self) -> types.SchematicReference:
        refs = self.get_schematic_references()
        if len(refs) == 0:
            raise EeException("This part does not contain any schematic references{}".
                              format(", uri=" + self.uri if self.uri else ""))
        if len(refs) != 1:
            raise EeException("This part does not contain exactly one schematic reference: {}".
                              format(", ".join([ref.referenceProp for ref in refs])))

        return refs[0]

    # MPNs

    def add_mpn(self, mpn: str):
        self.get_mpns().append(types.PartNumber(value=mpn))

    def get_mpns(self) -> List[types.PartNumber]:
        return self.xml.referencesProp.part_numberProp

    def get_only_mpn(self) -> Optional[types.PartNumber]:
        return next(iter(self.get_mpns()), None)

    def get_exactly_one_mpn(self) -> types.PartNumber:
        mpns = self.get_mpns()
        if len(mpns) == 0:
            raise EeException("This part does not contain any manufacturer part numbers{}".
                              format(", uri=" + self.uri if self.uri else ""))
        if len(mpns) != 1:
            raise EeException("This part does not contain exactly one mpn: {}".
                              format(", ".join([mpn.valueProp for mpn in mpns])))

        return mpns[0]

    # SPNs

    def add_spn(self, mpn: str):
        self.get_spns().append(types.SupplierPartNumber(value=mpn))

    def get_spns(self) -> List[types.SupplierPartNumber]:
        return self.xml.referencesProp.supplier_part_numberProp

    def get_only_spn(self) -> Optional[types.SupplierPartNumber]:
        return next(iter(self.get_spns()), None)

    def get_exactly_one_spn(self) -> types.SupplierPartNumber:
        spns = self.get_spns()
        if len(spns) == 0:
            raise EeException("This part does not contain any manufacturer part numbers{}".
                              format(", uri=" + self.uri if self.uri else ""))
        if len(spns) != 1:
            raise EeException("This part does not contain exactly one spn: {}".
                              format(", ".join([spn.valueProp for spn in spns])))

        return spns[0]

    # Price breaks

    def add_price_break(self, quantity, price: Money):
        amount = types.Amount(value=price.amount, currency=price.currency)
        pb = types.PriceBreak(quantity=quantity, amount=amount)
        self.xml.price_breaksProp.price_break.append(pb)

    # Links

    def get_links(self) -> List[types.Link]:
        return self.xml.linksProp.link

    # Facts

    def get_facts(self) -> List[types.Fact]:
        return self.xml.factsProp.fact

    def find_fact(self, key: str) -> Optional[types.Fact]:
        return next((f for f in self.get_facts() if f.keyProp == key), None)


class Facts(object):
    def __init__(self, part):
        self.part = part

    def add(self, key: str, value: str, label=None):
        self.part.get_facts().append(types.Fact(key=key, label=label, value=value))


class Entry(object):
    def __init__(self, new: bool, part: types.Part):
        self.new = new
        self.part = part

        self.pn = next((p.valueProp for p in Part(part).get_mpns()), None)


class AssemblyPart(object):
    def __init__(self, uri: Optional[str]):
        self.count = 0
        self.sub_parts: List[AssemblyPart] = []
        self.references = ReferenceList(uri)

    def add_sub_part(self, ap: "AssemblyPart"):
        self.sub_parts.append(ap)


class Assembly(object):
    def __init__(self):
        self.parts: List[AssemblyPart] = []


class PartDb(object):
    def __init__(self):
        self.parts: List[Entry] = []
        self.pn_index: MutableMapping[str, Entry] = {}
        self.new_entries = 0
        self._assembly: Optional[Assembly] = None

    def add_entry(self, part: Union[Part, types.Part], new: bool):
        if isinstance(part, Part):
            part = part.underlying

        e = Entry(new, part)
        self.parts.append(e)

        if e.pn:
            self.pn_index[e.pn] = e

        if e.new:
            self.new_entries = self.new_entries + 1

    def iterparts(self, sort=False) -> Iterator[types.Part]:
        it = (e.part for e in self.parts)
        return sorted(it, key=lambda p: p.uriProp) if sort else it

    def size(self) -> int:
        return len(self.parts)

    def find_by_pn(self, pn: str) -> Optional[types.Part]:
        entry = self.pn_index.get(pn, None)
        return entry.part if entry else None

    @property
    def has_assembly(self):
        return self._assembly is not None

    @property
    def assembly(self):
        if self._assembly is None:
            self._assembly = Assembly()
        return self._assembly


def load_db(path: Path) -> PartDb:
    db = PartDb()

    with path.open("r") as f:
        part_db: types.PartDb = types.parse(f, silence=True)

    part_db.partsProp = part_db.partsProp or types.PartList()

    for p in part_db.partsProp.part:
        db.add_entry(p, False)

    return db


def find_root_tag(root):
    return next((tag for tag, klass in types.GDSClassesMapping.items() if klass == type(root)), None)


def save_db(path: Path, db: PartDb, sort=False):
    part_db = types.PartDb()

    if db.size() > 0:
        part_db.parts = types.PartList()

        for part in db.iterparts(sort=sort):
            p = Part(part)
            p.clean_xml()
            part_db.parts.partProp.append(p.underlying)

    if db.has_assembly:

        def to_xml(ap: AssemblyPart):
            xml = types.AssemblyPart()
            if ap.count != 0:
                xml.countProp = ap.count
            if ap.sub_parts:
                xml.sub_partsProp = types.AssemblyPartList([to_xml(ap_) for ap_ in ap.sub_parts])

            xml.set_references(ap.references.to_xml())

            return xml

        assembly = db.assembly
        part_list = types.AssemblyPartList()

        for ap in assembly.parts:
            part_list.add_assembly_part(to_xml(ap))

        part_db.assemblyProp = types.Assembly(assembly_parts=part_list)

    with path.open("w") as f:
        part_db.export(outfile=f, level=0, name_=find_root_tag(part_db))