"""Domain constants: roles, workflow stages, and the transition map.

Workflow note: an NCR in the "New Request" stage is awaiting Initial
Disposition — the initial-disposition review is the action a Disposition
Authority performs on a New Request, and it moves the NCR either to
Secondary Disposition (when secondary review is required) or straight to
Operations. All transitions are validated server-side against
ALLOWED_TRANSITIONS; anything else is rejected with HTTP 409.
"""
from enum import Enum


class Role(str, Enum):
    REQUESTER = "requester"
    DISPOSITION_AUTHORITY = "disposition_authority"
    SECONDARY_DISPOSITION_AUTHORITY = "secondary_disposition_authority"
    OPERATIONS = "operations"
    QC_INSPECTOR = "qc_inspector"
    COSTING = "costing"
    ADMIN = "admin"


ALL_ROLES: set[str] = {r.value for r in Role}

ROLE_LABELS: dict[str, str] = {
    Role.REQUESTER: "Requester",
    Role.DISPOSITION_AUTHORITY: "Disposition Authority",
    Role.SECONDARY_DISPOSITION_AUTHORITY: "Secondary Disposition Authority",
    Role.OPERATIONS: "Operations",
    Role.QC_INSPECTOR: "QC Inspector",
    Role.COSTING: "Costing",
    Role.ADMIN: "Admin",
}


class Stage(str, Enum):
    NEW_REQUEST = "new_request"
    SECONDARY_DISPOSITION = "secondary_disposition"
    OPERATIONS = "operations"
    QC_INSPECTION = "qc_inspection"
    COSTING = "costing"
    CLOSED = "closed"


STAGE_LABELS: dict[str, str] = {
    Stage.NEW_REQUEST: "New Request",
    Stage.SECONDARY_DISPOSITION: "Secondary Disposition",
    Stage.OPERATIONS: "Operations",
    Stage.QC_INSPECTION: "QC Inspection",
    Stage.COSTING: "Costing",
    Stage.CLOSED: "Closed",
}

# Stages an admin may reopen a closed NCR back into.
REOPEN_TARGET_STAGES: list[Stage] = [
    Stage.NEW_REQUEST,
    Stage.SECONDARY_DISPOSITION,
    Stage.OPERATIONS,
    Stage.QC_INSPECTION,
    Stage.COSTING,
]

ALLOWED_TRANSITIONS: dict[Stage, set[Stage]] = {
    Stage.NEW_REQUEST: {Stage.SECONDARY_DISPOSITION, Stage.OPERATIONS},
    Stage.SECONDARY_DISPOSITION: {Stage.OPERATIONS},
    Stage.OPERATIONS: {Stage.QC_INSPECTION},
    Stage.QC_INSPECTION: {Stage.COSTING},
    Stage.COSTING: {Stage.CLOSED},
    # Reopen (admin only, reason required) — enforced separately.
    Stage.CLOSED: set(REOPEN_TARGET_STAGES),
}

# Role allowed to act on the NCR in each stage (Admin is always allowed;
# Secondary Disposition additionally requires being an assigned authority).
STAGE_ACTING_ROLE: dict[Stage, Role] = {
    Stage.NEW_REQUEST: Role.DISPOSITION_AUTHORITY,
    Stage.SECONDARY_DISPOSITION: Role.SECONDARY_DISPOSITION_AUTHORITY,
    Stage.OPERATIONS: Role.OPERATIONS,
    Stage.QC_INSPECTION: Role.QC_INSPECTOR,
    Stage.COSTING: Role.COSTING,
}

# Owners to notify when an admin reopens an NCR into a given stage.
STAGE_OWNER_ROLE: dict[Stage, Role] = STAGE_ACTING_ROLE