"""Spec schema for node definitions.

`NodeSpec` is the serialized contract exposed to the frontend, MCP tools, and
SDKs. Core workflow node specs are generated from the DTO models plus
model-attached metadata; integration packages may generate them the same way or
register a prebuilt spec object.

Every property's `description` is LLM-readable copy — treat it as production
documentation, not internal notes. Spec lint enforces non-empty descriptions
and example coverage.
"""

from __future__ import annotations

from enum import Enum
from typing import Any, Optional

from pydantic import BaseModel, ConfigDict, Field

# Spec contract version. Bump when adding new PropertyType values or making
# breaking changes to the NodeSpec wire shape. SDK clients warn on mismatch.
SPEC_VERSION = "1.0.0"


class PropertyType(str, Enum):
    """Bounded vocabulary of property types the renderer dispatches on.

    Adding a value here requires a matching arm in the frontend
    `<PropertyInput>` switch and (where relevant) the SDK codegen template.
    """

    string = "string"
    number = "number"
    boolean = "boolean"
    options = "options"  # single-select dropdown
    multi_options = "multi_options"  # multi-select
    fixed_collection = "fixed_collection"  # repeating rows of sub-properties
    json = "json"  # arbitrary JSON object editor

    # Domain-specific reference types — values are UUIDs/keys looked up against
    # a reference catalog (list_tools, list_documents, list_recordings,
    # list_credentials).
    tool_refs = "tool_refs"
    document_refs = "document_refs"
    recording_ref = "recording_ref"
    credential_ref = "credential_ref"

    # Domain-specific input widgets
    mention_textarea = "mention_textarea"  # textarea with {{var}} mentions
    url = "url"


class NodeCategory(str, Enum):
    """Drives grouping in the AddNodePanel UI."""

    call_node = "call_node"
    global_node = "global_node"
    trigger = "trigger"
    integration = "integration"


class DisplayOptions(BaseModel):
    """Conditional visibility rules.

    `show` keys are AND-combined: this property is visible only when EVERY
    referenced field's value matches one of the listed values.

    `hide` keys are OR-combined: this property is hidden when ANY referenced
    field's value matches one of the listed values.

    Example:
        DisplayOptions(show={"extraction_enabled": [True]})
        DisplayOptions(show={"greeting_type": ["audio"]})
    """

    show: Optional[dict[str, list[Any]]] = None
    hide: Optional[dict[str, list[Any]]] = None

    model_config = ConfigDict(extra="forbid")


def evaluate_display_options(
    rules: Optional[DisplayOptions | dict[str, Any]],
    values: dict[str, Any],
) -> bool:
    """Reference implementation of the display_options visibility check.

    Mirrored 1:1 in the TypeScript renderer
    (`ui/src/components/flow/renderer/displayOptions.ts`). The golden
    fixtures in `display_options_fixtures.json` lock the two
    implementations together — update both whenever the semantics change.
    """
    if rules is None:
        return True

    if isinstance(rules, DisplayOptions):
        show = rules.show
        hide = rules.hide
    else:
        show = rules.get("show")
        hide = rules.get("hide")

    if show:
        for field, allowed in show.items():
            if values.get(field) not in allowed:
                return False

    if hide:
        for field, hidden in hide.items():
            if values.get(field) in hidden:
                return False

    return True


class PropertyOption(BaseModel):
    """An option in an `options` or `multi_options` dropdown."""

    value: str | int | bool | float
    label: str
    description: Optional[str] = None

    model_config = ConfigDict(extra="forbid")

    def to_mcp_dict(self) -> dict[str, Any]:
        """Lean projection for `get_node_type`: the `value` an LLM writes in
        code, plus a `description` when one carries real meaning. The UI
        `label` is dropped — it's the option's display string, never used
        when authoring."""
        out: dict[str, Any] = {"value": self.value}
        if self.description:
            out["description"] = self.description
        return out


class PropertyLayoutOptions(BaseModel):
    """Renderer layout hints for a property in the node editor."""

    column_span: Optional[int] = Field(
        default=None,
        ge=1,
        le=12,
        description="Number of columns to occupy in the editor's 12-column grid.",
    )

    model_config = ConfigDict(extra="forbid")


class NumberInputOptions(BaseModel):
    """Renderer hints for numeric inputs."""

    fractional: bool = Field(
        default=False,
        description="Allow arbitrary fractional values via step='any'.",
    )

    model_config = ConfigDict(extra="forbid")


class PropertyRendererOptions(BaseModel):
    """Typed renderer metadata for node properties.

    Add new renderer behavior here instead of using free-form property metadata.
    """

    layout: Optional[PropertyLayoutOptions] = None
    number_input: Optional[NumberInputOptions] = None

    model_config = ConfigDict(extra="forbid")


class PropertySpec(BaseModel):
    """Single field on a node.

    `description` is HUMAN-FACING — shown under the field in the edit
    dialog. Keep it concise and explain what the field does.

    `llm_hint` is LLM-FACING — appears only in the `get_node_type` MCP
    response and in SDK schema output. Use it for catalog tool references
    (e.g., "Use `list_recordings`"), array shape, expected value idioms,
    or anything that would be noise in the UI. Optional; omit when the
    `description` already suffices for both audiences.
    """

    name: str
    type: PropertyType
    display_name: str
    description: str = Field(
        ...,
        min_length=1,
        description="Human-facing explanation shown in the UI.",
    )
    llm_hint: Optional[str] = Field(
        default=None,
        description="LLM-only guidance; omitted from the UI.",
    )
    default: Any = None
    required: bool = False
    placeholder: Optional[str] = None

    display_options: Optional[DisplayOptions] = None

    # For `options` / `multi_options`
    options: Optional[list[PropertyOption]] = None

    # For `fixed_collection` — sub-properties of each row
    properties: Optional[list["PropertySpec"]] = None

    # Validation hints. Enforced by Pydantic where possible.
    min_value: Optional[float] = None
    max_value: Optional[float] = None
    min_length: Optional[int] = None
    max_length: Optional[int] = None
    pattern: Optional[str] = None

    # Renderer hint, e.g. "textarea" vs single-line for `string`.
    editor: Optional[str] = None

    # Typed metadata for renderer-specific behavior. Extend
    # `PropertyRendererOptions` when the renderer needs a new hint.
    renderer_options: Optional[PropertyRendererOptions] = None

    model_config = ConfigDict(extra="forbid")

    def to_mcp_dict(self) -> dict[str, Any]:
        """Lean projection of this property for the `get_node_type` MCP tool.

        Keeps only what an LLM needs to author a valid value: name, type,
        description, llm_hint, requiredness, default, enum options, nested
        row properties, and validation bounds. UI-rendering concerns
        (`display_name`, `placeholder`, `display_options`, `editor`,
        `renderer_options`) and null/empty fields are omitted — they're noise in the
        model's context and never appear in authored SDK code.
        """
        out: dict[str, Any] = {
            "name": self.name,
            "type": self.type.value,
            "description": self.description,
        }
        if self.llm_hint:
            out["llm_hint"] = self.llm_hint
        if self.required:
            out["required"] = True
        if self.default is not None:
            out["default"] = self.default
        if self.options:
            out["options"] = [opt.to_mcp_dict() for opt in self.options]
        if self.properties:
            out["properties"] = [prop.to_mcp_dict() for prop in self.properties]
        for constraint in (
            "min_value",
            "max_value",
            "min_length",
            "max_length",
            "pattern",
        ):
            value = getattr(self, constraint)
            if value is not None:
                out[constraint] = value
        return out


PropertySpec.model_rebuild()


class NodeExample(BaseModel):
    """A worked example LLMs can pattern-match. Keep small and realistic."""

    name: str
    description: Optional[str] = None
    data: dict[str, Any]

    model_config = ConfigDict(extra="forbid")


class GraphConstraints(BaseModel):
    """Per-node-type graph rules. WorkflowGraph enforces these at validation."""

    min_incoming: Optional[int] = None
    max_incoming: Optional[int] = None
    min_outgoing: Optional[int] = None
    max_outgoing: Optional[int] = None
    min_instances: Optional[int] = None
    max_instances: Optional[int] = None

    model_config = ConfigDict(extra="forbid")


class NodeSpec(BaseModel):
    """Single source of truth for a node type."""

    name: str  # machine name; matches the Pydantic discriminator value
    display_name: str
    description: str = Field(
        ...,
        min_length=1,
        description="Human-facing explanation shown in AddNodePanel.",
    )
    llm_hint: Optional[str] = Field(
        default=None,
        description="LLM-only guidance; omitted from the UI.",
    )
    docs_url: Optional[str] = Field(
        default=None,
        description="Documentation URL shown in the node editor.",
    )
    category: NodeCategory
    icon: str  # lucide-react icon name (e.g., "Play")
    version: str = "1.0.0"
    properties: list[PropertySpec]
    examples: list[NodeExample] = Field(default_factory=list)
    graph_constraints: Optional[GraphConstraints] = None

    model_config = ConfigDict(extra="forbid")

    def to_mcp_dict(self) -> dict[str, Any]:
        """Lean projection of this spec for the `get_node_type` MCP tool.

        Drops node-level UI metadata (`display_name`, `docs_url`, `category`,
        `icon`, `version`) and the per-property rendering concerns trimmed by
        `PropertySpec.to_mcp_dict`, leaving just the authoring-relevant
        schema the LLM consumes when composing a workflow. The full spec is
        still served verbatim to the frontend renderer (REST `node-types`
        route) and the SDK codegen / TS validator (`ts_bridge`), which need
        the dropped fields.
        """
        out: dict[str, Any] = {
            "name": self.name,
            "description": self.description,
        }
        if self.llm_hint:
            out["llm_hint"] = self.llm_hint
        out["properties"] = [prop.to_mcp_dict() for prop in self.properties]
        if self.examples:
            out["examples"] = [
                ex.model_dump(mode="json", exclude_none=True) for ex in self.examples
            ]
        if self.graph_constraints:
            constraints = self.graph_constraints.model_dump(
                mode="json", exclude_none=True
            )
            if constraints:
                out["graph_constraints"] = constraints
        return out