"""Pydantic data models for typing the FastAPI request/responses."""

from datetime import datetime, timezone
from enum import Enum
from typing import TYPE_CHECKING, Annotated, Literal

from pydantic import BaseModel, Field, PlainSerializer

from spoolman.database import models
from spoolman.math import length_from_weight
from spoolman.settings import SettingDefinition, SettingType

if TYPE_CHECKING:
    # Only for typing: spoolman.database.search reaches spoolman.database.filament,
    # which imports this module, so importing it for real would be circular.
    from spoolman.database import search


def datetime_to_str(dt: datetime) -> str:
    """Convert a datetime object to a string."""
    if dt.tzinfo is None:
        dt = dt.replace(tzinfo=timezone.utc)
    return dt.isoformat().replace("+00:00", "Z")


SpoolmanDateTime = Annotated[datetime, PlainSerializer(datetime_to_str)]


def _sanitize_color_hex(value: str | None) -> str | None:
    """Normalize a color code read from the database.

    Older releases could store a value with a leading ``#`` (see #780). Strip it and
    drop anything that still isn't a valid 6 or 8 character code, so that one bad row
    doesn't make the whole filament list unserializable.
    """
    if not value:
        return None
    clr = value.upper().removeprefix("#")
    if len(clr) not in (6, 8) or any(c not in "0123456789ABCDEF" for c in clr):
        return None
    return clr


def _sanitize_multi_color_hexes(value: str | None) -> str | None:
    """Normalize a comma-separated list of color codes read from the database."""
    if not value:
        return None
    colors = [c for c in (_sanitize_color_hex(part) for part in value.split(",")) if c is not None]
    if len(colors) < 2:  # noqa: PLR2004
        return None
    return ",".join(colors)


def _extra_fields_description(entity: str) -> str:
    r"""Build the description for an entity's ``extra`` field.

    Every value in the ``extra`` map is a JSON-encoded string, regardless of the field's
    configured type. For example, an ``integer`` field returns ``"42"`` (not ``42``) and a
    ``text`` field returns ``"\"hello\""``. Consumers must JSON-decode each value to get the
    typed value. This keeps the map uniformly typed as ``dict[str, str]`` on the wire.
    """
    return (
        f"Extra fields for this {entity}. Every value is a JSON-encoded string, regardless of the field's "
        'configured type: e.g. an integer field returns "42" (not 42) and a text field returns "\\"hello\\"". '
        "Consumers must JSON-decode each value. Query the /fields endpoint for the type of each field."
    )


def extra_fields_request_description(entity: str) -> str:
    """Build the description for an entity's ``extra`` field on a create/update request.

    Values are JSON-encoded strings, exactly as in the response. An update merges per key —
    a field left out of the map keeps whatever it held — and a null value means "no value
    for this field": nothing is stored, so it clears a value that was previously set. There
    is no other way to remove one.
    """
    return (
        f"Extra fields for this {entity}. Every value is a JSON-encoded string matching the field's "
        'configured type, e.g. "42" for an integer field and "\\"hello\\"" for a text field. '
        "Patching this map merges per key: a field left out of it keeps whatever it held. Pass null "
        "instead of a string to store no value for the field, which is how a value that has already "
        "been set is cleared."
    )


class Message(BaseModel):
    message: str = Field()


class TagConflictMessage(Message):
    """A tag UID is already linked to something else.

    Subclasses Message so the `message` key is where it is in every other error body, and
    adds the conflicting spool's ID so a client can offer to move the tag there instead of
    making the user go and find it.

    `spool_id` is optional because a tag identifies one thing and that thing is not always
    a spool -- see `models.Tag`. It is absent when the UID is held by something else, in
    which case `message` still says what; a client that cannot offer "move it here" without
    an id should fall back to reporting the message.
    """

    spool_id: int | None = Field(
        None,
        description="The spool the tag is already linked to, if it is a spool that holds it.",
        examples=[42],
    )


class SettingResponse(BaseModel):
    value: str = Field(description="Setting value.")
    is_set: bool = Field(description="Whether the setting has been set. If false, 'value' contains the default value.")
    type: SettingType = Field(description="Setting type. This corresponds with JSON types.")


class SettingKV(BaseModel):
    key: str = Field(description="Setting key.")
    setting: SettingResponse = Field(description="Setting value.")

    @staticmethod
    def from_db(definition: SettingDefinition, set_value: str | None) -> "SettingKV":
        """Create a new Pydantic vendor object from a database vendor object."""
        return SettingKV(
            key=definition.key,
            setting=SettingResponse(
                value=set_value if set_value is not None else definition.default,
                is_set=set_value is not None,
                type=definition.type,
            ),
        )


class Vendor(BaseModel):
    id: int = Field(description="Unique internal ID of this vendor.")
    registered: SpoolmanDateTime = Field(description="When the vendor was registered in the database. UTC Timezone.")
    name: str = Field(max_length=64, description="Vendor name.", examples=["Polymaker"])
    comment: str | None = Field(
        None,
        max_length=1024,
        description="Free text comment about this vendor.",
        examples=[""],
    )
    empty_spool_weight: float | None = Field(
        None,
        ge=0,
        description="The empty spool weight, in grams.",
        examples=[140],
    )
    external_id: str | None = Field(
        None,
        max_length=256,
        description=(
            "Set if this vendor comes from an external database. This contains the ID in the external database."
        ),
        examples=["eSun"],
    )
    extra: dict[str, str] = Field(
        description=_extra_fields_description("vendor"),
    )

    @staticmethod
    def from_db(item: models.Vendor) -> "Vendor":
        """Create a new Pydantic vendor object from a database vendor object."""
        return Vendor(
            id=item.id,
            registered=item.registered,
            name=item.name,
            comment=item.comment,
            empty_spool_weight=item.empty_spool_weight,
            external_id=item.external_id,
            extra={field.key: field.value for field in item.extra},
        )


class MultiColorDirection(Enum):
    """Enum for multi-color direction."""

    COAXIAL = "coaxial"
    LONGITUDINAL = "longitudinal"


class Filament(BaseModel):
    id: int = Field(description="Unique internal ID of this filament type.")
    registered: SpoolmanDateTime = Field(description="When the filament was registered in the database. UTC Timezone.")
    name: str | None = Field(
        None,
        max_length=64,
        description=(
            "Filament name, to distinguish this filament type among others from the same vendor."
            "Should contain its color for example."
        ),
        examples=["PolyTerra™ Charcoal Black"],
    )
    vendor: Vendor | None = Field(None, description="The vendor of this filament type.")
    material: str | None = Field(
        None,
        max_length=64,
        description="The material of this filament, e.g. PLA.",
        examples=["PLA"],
    )
    price: float | None = Field(
        None,
        ge=0,
        description="The price of this filament in the system configured currency.",
        examples=[20.0],
    )
    density: float = Field(gt=0, description="The density of this filament in g/cm3.", examples=[1.24])
    diameter: float = Field(gt=0, description="The diameter of this filament in mm.", examples=[1.75])
    weight: float | None = Field(
        None,
        gt=0,
        description="The weight of the filament in a full spool, in grams.",
        examples=[1000],
    )
    spool_weight: float | None = Field(None, ge=0, description="The empty spool weight, in grams.", examples=[140])
    article_number: str | None = Field(
        None,
        max_length=64,
        description="Vendor article number, e.g. EAN, QR code, etc.",
        examples=["PM70820"],
    )
    comment: str | None = Field(
        None,
        max_length=1024,
        description="Free text comment about this filament type.",
        examples=[""],
    )
    settings_extruder_temp: int | None = Field(
        None,
        ge=0,
        description="Overridden extruder temperature, in °C.",
        examples=[210],
    )
    settings_bed_temp: int | None = Field(
        None,
        ge=0,
        description="Overridden bed temperature, in °C.",
        examples=[60],
    )
    color_hex: str | None = Field(
        None,
        min_length=6,
        max_length=8,
        description=(
            "Hexadecimal color code of the filament, e.g. FF0000 for red. Supports alpha channel at the end. "
            "If it's a multi-color filament, the multi_color_hexes field is used instead."
        ),
        examples=["FF0000"],
    )
    multi_color_hexes: str | None = Field(
        None,
        min_length=6,
        description=(
            "Hexadecimal color code of the filament, e.g. FF0000 for red. Supports alpha channel at the end. "
            "Specifying multiple colors separated by commas. "
            "Also set the multi_color_direction field if you specify multiple colors."
        ),
        examples=["FF0000,00FF00,0000FF"],
    )
    multi_color_direction: MultiColorDirection | None = Field(
        None,
        description=("Type of multi-color filament. Only set if the multi_color_hexes field is set."),
        examples=["coaxial", "longitudinal"],
    )
    external_id: str | None = Field(
        None,
        max_length=256,
        description=(
            "Set if this filament comes from an external database. This contains the ID in the external database."
        ),
        examples=["polymaker_pla_polysonicblack_1000_175"],
    )
    extra: dict[str, str] = Field(
        description=_extra_fields_description("filament"),
    )

    @staticmethod
    def from_db(item: models.Filament) -> "Filament":
        """Create a new Pydantic filament object from a database filament object."""
        return Filament(
            id=item.id,
            registered=item.registered,
            name=item.name,
            vendor=Vendor.from_db(item.vendor) if item.vendor is not None else None,
            material=item.material,
            price=item.price,
            density=item.density,
            diameter=item.diameter,
            weight=item.weight,
            spool_weight=item.spool_weight,
            article_number=item.article_number,
            comment=item.comment,
            settings_extruder_temp=item.settings_extruder_temp,
            settings_bed_temp=item.settings_bed_temp,
            color_hex=_sanitize_color_hex(item.color_hex),
            multi_color_hexes=_sanitize_multi_color_hexes(item.multi_color_hexes),
            multi_color_direction=(
                MultiColorDirection(item.multi_color_direction) if item.multi_color_direction is not None else None
            ),
            external_id=item.external_id,
            extra={field.key: field.value for field in item.extra},
        )


class SpoolTag(BaseModel):
    """A physical NFC/RFID tag linked to a spool."""

    uid: str = Field(
        description=(
            "The tag's hardware UID, normalized to uppercase hexadecimal with separators "
            "stripped. Unique across all spools: one tag identifies exactly one spool."
        ),
        examples=["04A2B3C4D5E6F7"],
    )
    format: str | None = Field(
        None,
        description=(
            "What kind of tag this is, e.g. openprinttag, ntag, bambu, tigertag. "
            "Informational, free-form, and not validated against a fixed list."
        ),
        examples=["ntag"],
    )
    added: SpoolmanDateTime = Field(description="When the tag was linked to the spool. UTC Timezone.")

    @staticmethod
    def from_db(item: models.Tag) -> "SpoolTag":
        """Create a new Pydantic spool tag object from a database spool tag object."""
        return SpoolTag(uid=item.uid, format=item.format, added=item.added)


class Spool(BaseModel):
    id: int = Field(description="Unique internal ID of this spool of filament.")
    registered: SpoolmanDateTime = Field(description="When the spool was registered in the database. UTC Timezone.")
    first_used: SpoolmanDateTime | None = Field(
        None,
        description="First logged occurence of spool usage. UTC Timezone.",
    )
    last_used: SpoolmanDateTime | None = Field(
        None,
        description="Last logged occurence of spool usage. UTC Timezone.",
    )
    filament: Filament = Field(description="The filament type of this spool.")
    price: float | None = Field(
        None,
        ge=0,
        description="The price of this spool in the system configured currency.",
        examples=[20.0],
    )
    remaining_weight: float | None = Field(
        default=None,
        ge=0,
        description=(
            "Estimated remaining weight of filament on the spool in grams. "
            "Only set if the filament type has a weight set."
        ),
        examples=[500.6],
    )
    initial_weight: float | None = Field(
        default=None,
        ge=0,
        description=("The initial weight, in grams, of the filament on the spool (net weight)."),
        examples=[1246],
    )
    spool_weight: float | None = Field(
        default=None,
        ge=0,
        description=("Weight of an empty spool (tare weight)."),
        examples=[246],
    )
    used_weight: float = Field(
        ge=0,
        description="Consumed weight of filament from the spool in grams.",
        examples=[500.3],
    )
    remaining_length: float | None = Field(
        default=None,
        ge=0,
        description=(
            "Estimated remaining length of filament on the spool in millimeters."
            " Only set if the filament type has a weight set."
        ),
        examples=[5612.4],
    )
    used_length: float = Field(
        ge=0,
        description="Consumed length of filament from the spool in millimeters.",
        examples=[50.7],
    )
    location: str | None = Field(
        None,
        max_length=64,
        description="Where this spool can be found.",
        examples=["Shelf A"],
    )
    lot_nr: str | None = Field(
        None,
        max_length=64,
        description="Vendor manufacturing lot/batch number of the spool.",
        examples=["52342"],
    )
    comment: str | None = Field(
        None,
        max_length=1024,
        description="Free text comment about this specific spool.",
        examples=[""],
    )
    archived: bool = Field(description="Whether this spool is archived and should not be used anymore.")
    extra: dict[str, str] = Field(
        description=_extra_fields_description("spool"),
    )
    tags: list[SpoolTag] = Field(
        default_factory=list,
        description=(
            "NFC/RFID tags linked to this spool. A spool can carry more than one tag, e.g. when a "
            "vendor tag has been copied onto a blank sticker. Empty if none are linked."
        ),
    )

    @staticmethod
    def from_db(item: models.Spool) -> "Spool":
        """Create a new Pydantic spool object from a database spool object."""
        filament = Filament.from_db(item.filament)

        remaining_weight: float | None = None
        remaining_length: float | None = None

        if item.initial_weight is not None:
            remaining_weight = max(item.initial_weight - item.used_weight, 0)
            remaining_length = length_from_weight(
                weight=remaining_weight,
                density=filament.density,
                diameter=filament.diameter,
            )
        elif filament.weight is not None:
            remaining_weight = max(filament.weight - item.used_weight, 0)
            remaining_length = length_from_weight(
                weight=remaining_weight,
                density=filament.density,
                diameter=filament.diameter,
            )

        used_length = length_from_weight(
            weight=item.used_weight,
            density=filament.density,
            diameter=filament.diameter,
        )

        return Spool(
            id=item.id,
            registered=item.registered,
            first_used=item.first_used,
            last_used=item.last_used,
            filament=filament,
            price=item.price,
            initial_weight=item.initial_weight,
            spool_weight=item.spool_weight,
            used_weight=item.used_weight,
            used_length=used_length,
            remaining_weight=remaining_weight,
            remaining_length=remaining_length,
            location=item.location,
            lot_nr=item.lot_nr,
            comment=item.comment,
            archived=item.archived if item.archived is not None else False,
            extra={field.key: field.value for field in item.extra},
            tags=[SpoolTag.from_db(tag) for tag in item.tags],
        )


class SpoolGroup(BaseModel):
    """A group of spools with server-computed aggregates.

    Returned by the ``/spool/group`` endpoint. Spools are grouped by one axis
    (``group_by``); the aggregates are computed over the matching spools of each
    group so the client can paginate whole groups without fetching every spool.
    """

    group_by: str = Field(
        description="The field the spools are grouped by.",
        examples=["filament"],
    )
    key: str | None = Field(
        None,
        description=(
            "The group key. For group_by=filament/vendor this is the entity ID as a string; for "
            "material/location and extra fields it is the value. Null when the grouped "
            "field is unset (e.g. spools with no location or a filament with no vendor)."
        ),
        examples=["12"],
    )
    spool_count: int = Field(description="Number of matching spools in this group.", examples=[6])
    in_use_count: int = Field(
        description="Number of matching spools that have been used (used_weight > 0).",
        examples=[2],
    )
    total_remaining_weight: float | None = Field(
        None,
        description="Sum of remaining filament weight across the group's matching spools, in grams.",
        examples=[3120.0],
    )
    last_used: SpoolmanDateTime | None = Field(
        None,
        description="Most recent last_used across the group's matching spools. UTC Timezone.",
    )
    filament: Filament | None = Field(
        None,
        description="The filament, embedded for group_by=filament so the header needs no extra request.",
    )
    vendor: Vendor | None = Field(
        None,
        description="The vendor, embedded for group_by=vendor.",
    )


class SearchResultSpool(BaseModel):
    """A spool that matched a search, with which field matched."""

    spool: Spool = Field(description="The matching spool.")
    match_field: str = Field(
        description=(
            "Which field matched the query: a native field name (e.g. 'comment', 'location', "
            "'lot_nr'), 'id' for an exact spool-id match, or 'extra.<key>' for an extra field."
        ),
        examples=["comment"],
    )


class SearchResultFilamentSpool(BaseModel):
    """A spool of a filament that matched a search, in the fields needed to offer it as a shortcut."""

    id: int = Field(description="Unique internal ID of this spool of filament.")
    remaining_weight: float | None = Field(
        default=None,
        ge=0,
        description=(
            "Estimated remaining weight of filament on the spool in grams. "
            "Only set if the spool or its filament type has a weight set."
        ),
        examples=[500.6],
    )
    location: str | None = Field(
        None,
        max_length=64,
        description="Where this spool can be found.",
        examples=["Shelf A"],
    )
    archived: bool = Field(description="Whether this spool is archived and should not be used anymore.")

    @staticmethod
    def from_db(item: "search.FilamentSpool", filament_weight: float | None) -> "SearchResultFilamentSpool":
        """Create the compact spool object, deriving its weight the way `Spool.from_db` does."""
        remaining_weight: float | None = None
        if item.initial_weight is not None:
            remaining_weight = max(item.initial_weight - item.used_weight, 0)
        elif filament_weight is not None:
            remaining_weight = max(filament_weight - item.used_weight, 0)

        return SearchResultFilamentSpool(
            id=item.id,
            remaining_weight=remaining_weight,
            location=item.location,
            archived=item.archived,
        )


class SearchResultFilament(BaseModel):
    """A filament that matched a search, with which field matched."""

    filament: Filament = Field(description="The matching filament.")
    match_field: str = Field(
        description=(
            "Which field matched the query: a native field name (e.g. 'name', 'material', "
            "'article_number', 'comment'), 'color' for a color-similarity match, or 'extra.<key>'."
        ),
        examples=["color"],
    )
    spools: list[SearchResultFilamentSpool] | None = Field(
        default=None,
        description=(
            "The filament's first spools, oldest id first, so a filament hit can be followed "
            "straight to one of its spools. Only present if spools_per_filament was requested. "
            "Obeys allow_archived like the rest of the response."
        ),
    )
    spool_count: int | None = Field(
        default=None,
        description=(
            "How many spools this filament has in total, of which `spools` holds at most "
            "spools_per_filament. Only present if spools_per_filament was requested."
        ),
        examples=[3],
    )


class SearchResultVendor(BaseModel):
    """A vendor that matched a search, with which field matched."""

    vendor: Vendor = Field(description="The matching vendor.")
    match_field: str = Field(
        description="Which field matched the query: 'name', 'comment', or 'extra.<key>'.",
        examples=["name"],
    )


class SearchResults(BaseModel):
    """Categorized results of a cross-entity search."""

    spools: list[SearchResultSpool] = Field(description="Matching spools, best matches first.")
    filaments: list[SearchResultFilament] = Field(description="Matching filaments, best matches first.")
    vendors: list[SearchResultVendor] = Field(description="Matching vendors, best matches first.")
    is_color_query: bool = Field(
        description=(
            "Whether the query was recognized as a color (hex code or CSS color name), in which case "
            "the filament results include color-similarity matches and a threshold slider is relevant."
        ),
        examples=[False],
    )


class TagScan(BaseModel):
    """One tag read reported by a reader-side agent.

    Scans are ephemeral: they are broadcast to the scan websockets and never stored. The
    match is resolved server-side and included, so an agent that ignores websockets
    entirely can use the scan endpoint as a one-shot lookup.
    """

    uid: str = Field(
        description="The scanned tag's UID, normalized to uppercase hexadecimal with separators stripped.",
        examples=["04A2B3C4D5E6F7"],
    )
    reader_id: str = Field(
        description=(
            "Which reader reported the scan. Either the id the agent sent, or one derived from its "
            "network address when it sent none."
        ),
        examples=["printer-voron"],
    )
    name: str | None = Field(
        None,
        description="Human-readable name for the reader, if it sent one.",
        examples=["Voron spool holder"],
    )
    format: str | None = Field(
        None,
        description="What kind of tag this is, if the agent could tell.",
        examples=["ntag"],
    )
    payload_b64: str | None = Field(
        None,
        description=(
            "The tag's raw contents, base64-encoded, if the agent read them. Carried through "
            "untouched: Spoolman does not decode tag contents."
        ),
    )
    matched_spool_id: int | None = Field(
        None,
        description="The spool this tag is linked to, or null if the tag is not known to Spoolman.",
        examples=[42],
    )
    spool: Spool | None = Field(
        None,
        description="The matched spool, so a client needs no follow-up request. Null if the tag is unknown.",
    )


class TagReader(BaseModel):
    """A reader that has reported a scan recently.

    The registry is in-memory and is not persisted: a reader reappears the moment it
    scans again, and the list is empty after a restart until one does.
    """

    reader_id: str = Field(description="The reader's id.", examples=["printer-voron"])
    name: str | None = Field(
        None,
        description="Human-readable name for the reader, if it has sent one.",
        examples=["Voron spool holder"],
    )
    last_seen: SpoolmanDateTime = Field(description="When this reader last reported a scan. UTC Timezone.")


class Info(BaseModel):
    version: str = Field(examples=["0.7.0"])
    debug_mode: bool = Field(examples=[False])
    automatic_backups: bool = Field(examples=[True])
    data_dir: str = Field(examples=["/home/app/.local/share/spoolman"])
    logs_dir: str = Field(examples=["/home/app/.local/share/spoolman"])
    backups_dir: str = Field(examples=["/home/app/.local/share/spoolman/backups"])
    db_type: str = Field(examples=["sqlite"])
    external_db_name: str = Field(
        description="Display name for the external filament library, configurable via EXTERNAL_DB_NAME.",
        examples=["SpoolmanDB"],
    )
    git_commit: str | None = Field(None, examples=["a1b2c3d"])
    build_date: SpoolmanDateTime | None = Field(None, examples=["2021-01-01T00:00:00Z"])


class HealthCheck(BaseModel):
    status: str = Field(examples=["healthy"])


class BackupResponse(BaseModel):
    path: str = Field(
        description="Path to the created backup file.",
        examples=["/home/app/.local/share/spoolman/backups/spoolman.db"],
    )
    created: bool = Field(
        default=True,
        description=(
            "Whether this call wrote a new backup. False means an existing one was returned "
            "instead, either because the database has not changed since it was taken or because "
            "one was made very recently. Rotating discards the oldest restore point, so it is "
            "deliberately not done more often than necessary."
        ),
        examples=[True],
    )


class EventType(str, Enum):
    """Event types."""

    ADDED = "added"
    UPDATED = "updated"
    DELETED = "deleted"
    # Only ever emitted on the dedicated scan websockets (see TagScanEvent), never on the
    # entity ones, so no existing consumer can receive it.
    SCANNED = "scanned"


class Event(BaseModel):
    """Event."""

    type: EventType = Field(description="Event type.")
    resource: str = Field(description="Resource type.")
    date: SpoolmanDateTime = Field(description="When the event occured. UTC Timezone.")
    payload: BaseModel


class SpoolEvent(Event):
    """Event."""

    payload: Spool = Field(description="Updated spool.")
    resource: Literal["spool"] = Field(description="Resource type.")


class FilamentEvent(Event):
    """Event."""

    payload: Filament = Field(description="Updated filament.")
    resource: Literal["filament"] = Field(description="Resource type.")


class VendorEvent(Event):
    """Event."""

    payload: Vendor = Field(description="Updated vendor.")
    resource: Literal["vendor"] = Field(description="Resource type.")


class SettingEvent(Event):
    """Event."""

    payload: SettingKV = Field(description="Updated setting.")
    resource: Literal["setting"] = Field(description="Resource type.")


class TagScanEvent(Event):
    """A tag was scanned by a reader.

    Travels ONLY on the dedicated scan websockets, which are a separate subscription tree
    from the entity ones. It therefore never reaches the root /api/v1/ websocket, whose
    subscribers asked to hear about changes to data -- and a scan changes nothing.
    """

    payload: TagScan = Field(description="The scan.")
    resource: Literal["tag_scan"] = Field(description="Resource type.")