dify/api/core/app/segments/factory.py

from collections.abc import Mapping
from typing import Any

from configs import dify_config

from .exc import VariableError
from .segments import (
    ArrayAnySegment,
    FloatSegment,
    IntegerSegment,
    NoneSegment,
    ObjectSegment,
    Segment,
    StringSegment,
)
from .types import SegmentType
from .variables import (
    ArrayNumberVariable,
    ArrayObjectVariable,
    ArrayStringVariable,
    FloatVariable,
    IntegerVariable,
    ObjectVariable,
    SecretVariable,
    StringVariable,
    Variable,
)


def build_variable_from_mapping(mapping: Mapping[str, Any], /) -> Variable:
    if (value_type := mapping.get("value_type")) is None:
        raise VariableError("missing value type")
    if not mapping.get("name"):
        raise VariableError("missing name")
    if (value := mapping.get("value")) is None:
        raise VariableError("missing value")
    match value_type:
        case SegmentType.STRING:
            result = StringVariable.model_validate(mapping)
        case SegmentType.SECRET:
            result = SecretVariable.model_validate(mapping)
        case SegmentType.NUMBER if isinstance(value, int):
            result = IntegerVariable.model_validate(mapping)
        case SegmentType.NUMBER if isinstance(value, float):
            result = FloatVariable.model_validate(mapping)
        case SegmentType.NUMBER if not isinstance(value, float | int):
            raise VariableError(f"invalid number value {value}")
        case SegmentType.OBJECT if isinstance(value, dict):
            result = ObjectVariable.model_validate(mapping)
        case SegmentType.ARRAY_STRING if isinstance(value, list):
            result = ArrayStringVariable.model_validate(mapping)
        case SegmentType.ARRAY_NUMBER if isinstance(value, list):
            result = ArrayNumberVariable.model_validate(mapping)
        case SegmentType.ARRAY_OBJECT if isinstance(value, list):
            result = ArrayObjectVariable.model_validate(mapping)
        case _:
            raise VariableError(f"not supported value type {value_type}")
    if result.size > dify_config.MAX_VARIABLE_SIZE:
        raise VariableError(f"variable size {result.size} exceeds limit {dify_config.MAX_VARIABLE_SIZE}")
    return result


def build_segment(value: Any, /) -> Segment:
    if value is None:
        return NoneSegment()
    if isinstance(value, str):
        return StringSegment(value=value)
    if isinstance(value, int):
        return IntegerSegment(value=value)
    if isinstance(value, float):
        return FloatSegment(value=value)
    if isinstance(value, dict):
        return ObjectSegment(value=value)
    if isinstance(value, list):
        return ArrayAnySegment(value=value)
    raise ValueError(f"not supported value {value}")