from __future__ import annotations

from datetime import datetime
from typing import Literal

from pydantic import BaseModel, ConfigDict, Field, model_validator

from govoplan_core.core.approvals import ApprovalActorSelector, ApprovalStepDefinition


class CampaignApprovalSelectorInput(BaseModel):
    model_config = ConfigDict(extra="forbid")

    kind: Literal["account", "group", "role", "function_assignment", "any_account"]
    value: str = Field(min_length=1, max_length=255)
    label: str | None = Field(default=None, max_length=255)


class CampaignApprovalStepInput(BaseModel):
    model_config = ConfigDict(extra="forbid")

    key: str = Field(min_length=1, max_length=120)
    label: str = Field(min_length=1, max_length=255)
    selectors: list[CampaignApprovalSelectorInput] = Field(min_length=1, max_length=500)
    required_approvals: int = Field(default=1, ge=1, le=500)
    rejection_policy: Literal["fail_fast", "collect"] = "fail_fast"
    due_at: datetime | None = None
    signature_required: bool = False
    forbidden_evidence_roles: list[
        Literal["author", "owner", "validator", "builder", "reviewer"]
    ] = Field(default_factory=list, max_length=5)

    def to_definition(self) -> ApprovalStepDefinition:
        return ApprovalStepDefinition(
            key=self.key,
            label=self.label,
            selectors=tuple(
                ApprovalActorSelector(item.kind, item.value, item.label)
                for item in self.selectors
            ),
            required_approvals=self.required_approvals,
            rejection_policy=self.rejection_policy,
            due_at=self.due_at,
            signature_required=self.signature_required,
            forbidden_evidence_roles=tuple(self.forbidden_evidence_roles),
        )


class CampaignApprovalRequestInput(BaseModel):
    model_config = ConfigDict(extra="forbid")

    title: str = Field(
        default="Approve Campaign delivery", min_length=1, max_length=255
    )
    description: str | None = Field(default=None, max_length=10_000)
    steps: list[CampaignApprovalStepInput] = Field(default_factory=list, max_length=100)
    template_id: str | None = Field(default=None, max_length=36)
    template_revision: int | None = Field(default=None, ge=1)
    unique_actors_across_steps: bool = True
    expires_at: datetime | None = None
    policy_refs: list[str] = Field(default_factory=list, max_length=500)
    idempotency_key: str = Field(min_length=1, max_length=160)

    @model_validator(mode="after")
    def validate_source(self) -> "CampaignApprovalRequestInput":
        template = self.template_id is not None or self.template_revision is not None
        if template and (self.template_id is None or self.template_revision is None):
            raise ValueError("Template id and revision must be supplied together.")
        if template and self.steps:
            raise ValueError("Use either an Approval template or inline steps.")
        if not template and not self.steps:
            raise ValueError(
                "At least one Approval step is required without a template."
            )
        return self


__all__ = ["CampaignApprovalRequestInput"]