import pandas as pd
from pydantic import BaseModel, Field, ConfigDict

from contracts.RepoContext import Language


class DependencyNode(BaseModel):
    """A single node in the dependency graph."""
    model_config = ConfigDict(frozen=True)
    
    id: str = Field(..., description="Unique identifier (file path or module name)")
    label: str = Field(..., description="Human-readable label")
    language: Language
    is_external: bool = Field(
        default=False,
        description="True if the dependency is outside the repository",
    )


class DependencyEdge(BaseModel):
    """A directed edge from source → target (source depends on target)."""
    source: str = Field(..., description="Node id of the dependant")
    target: str = Field(..., description="Node id of the dependency")
    kind: str = Field(
        default="import",
        description="Edge kind: import, include, inherit, call, etc.",
    )


class DependencyGraph(BaseModel):
    """Complete dependency graph result."""
    root: str = Field(..., description="Entrypoint node id")
    nodes: list[DependencyNode]
    edges: list[DependencyEdge]
    metadata: dict[str, str] = Field(default_factory=dict)


class AnalyzeResult(BaseModel):
    """Return shape of :func:`analyze`."""
    model_config = ConfigDict(arbitrary_types_allowed=True)

    df: pd.DataFrame
    isolated: list[DependencyNode]
    leaf_no_deps: list[DependencyNode]
    entry_no_dependents: list[DependencyNode]
    widely_used: list[tuple[DependencyNode, int]]
    used_by_packages: dict[DependencyNode, int]
    wccs: list[set[DependencyNode]]
    sccs: list[set[DependencyNode]]
    node2comm: dict[DependencyNode, int]
    comms: list[set[DependencyNode]]