from __future__ import annotations

from datetime import datetime
from typing import Any, Literal

from pydantic import BaseModel, ConfigDict, Field, model_validator

from govoplan_poll.backend.schemas import PollResultSummaryResponse


SchedulingStatus = Literal["draft", "collecting", "closed", "decided", "handed_off", "cancelled", "archived"]
SchedulingParticipantType = Literal["internal", "external", "resource"]
SchedulingParticipantStatus = Literal["draft", "invited", "responded", "declined", "removed"]
SchedulingResultVisibility = Literal["organizer", "after_response", "after_close", "public"]


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

    enabled: bool = False
    calendar_id: str | None = Field(default=None, max_length=36)
    freebusy_enabled: bool = False
    tentative_holds_enabled: bool = False
    create_event_on_decision: bool = False


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

    label: str | None = Field(default=None, max_length=500)
    description: str | None = None
    start_at: datetime
    end_at: datetime
    timezone: str | None = Field(default=None, max_length=100)
    location: str | None = Field(default=None, max_length=500)
    metadata: dict[str, Any] = Field(default_factory=dict)

    @model_validator(mode="after")
    def validate_range(self) -> "SchedulingCandidateSlotInput":
        if self.end_at <= self.start_at:
            raise ValueError("end_at must be after start_at")
        return self


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

    respondent_id: str | None = Field(default=None, max_length=255)
    display_name: str | None = Field(default=None, max_length=500)
    email: str | None = Field(default=None, max_length=320)
    participant_type: SchedulingParticipantType = "external"
    required: bool = True
    metadata: dict[str, Any] = Field(default_factory=dict)


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

    title: str = Field(min_length=1, max_length=500)
    description: str | None = None
    location: str | None = Field(default=None, max_length=500)
    timezone: str = Field(default="UTC", max_length=100)
    status: Literal["draft", "collecting"] = "draft"
    deadline_at: datetime | None = None
    allow_external_participants: bool = True
    allow_participant_updates: bool = True
    result_visibility: SchedulingResultVisibility = "after_close"
    calendar: SchedulingCalendarPreferences = Field(default_factory=SchedulingCalendarPreferences)
    slots: list[SchedulingCandidateSlotInput] = Field(default_factory=list, min_length=1)
    participants: list[SchedulingParticipantInput] = Field(default_factory=list)
    create_participant_invitations: bool = True
    metadata: dict[str, Any] = Field(default_factory=dict)


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

    title: str | None = Field(default=None, min_length=1, max_length=500)
    description: str | None = None
    location: str | None = Field(default=None, max_length=500)
    deadline_at: datetime | None = None
    allow_external_participants: bool | None = None
    allow_participant_updates: bool | None = None
    result_visibility: SchedulingResultVisibility | None = None
    calendar: SchedulingCalendarPreferences | None = None
    metadata: dict[str, Any] | None = None


class SchedulingCandidateSlotResponse(BaseModel):
    id: str
    poll_option_id: str | None = None
    label: str
    description: str | None = None
    start_at: datetime
    end_at: datetime
    timezone: str
    location: str | None = None
    position: int
    freebusy_checked_at: datetime | None = None
    freebusy_status: str | None = None
    freebusy_conflicts: list[dict[str, Any]] = Field(default_factory=list)
    tentative_hold_event_id: str | None = None
    metadata: dict[str, Any] = Field(default_factory=dict)


class SchedulingParticipantResponse(BaseModel):
    id: str
    respondent_id: str | None = None
    display_name: str | None = None
    email: str | None = None
    participant_type: str
    required: bool
    status: str
    poll_invitation_id: str | None = None
    invitation_token: str | None = None
    last_invited_at: datetime | None = None
    responded_at: datetime | None = None
    metadata: dict[str, Any] = Field(default_factory=dict)


class SchedulingRequestResponse(BaseModel):
    id: str
    tenant_id: str
    title: str
    description: str | None = None
    location: str | None = None
    timezone: str
    status: str
    poll_id: str | None = None
    selected_slot_id: str | None = None
    organizer_user_id: str | None = None
    deadline_at: datetime | None = None
    allow_external_participants: bool
    allow_participant_updates: bool
    result_visibility: str
    calendar_integration_enabled: bool
    calendar_id: str | None = None
    calendar_freebusy_enabled: bool
    calendar_hold_enabled: bool
    create_calendar_event_on_decision: bool
    calendar_event_id: str | None = None
    handed_off_at: datetime | None = None
    cancelled_at: datetime | None = None
    created_at: datetime
    updated_at: datetime
    metadata: dict[str, Any] = Field(default_factory=dict)
    slots: list[SchedulingCandidateSlotResponse] = Field(default_factory=list)
    participants: list[SchedulingParticipantResponse] = Field(default_factory=list)


class SchedulingRequestListResponse(BaseModel):
    requests: list[SchedulingRequestResponse] = Field(default_factory=list)


class SchedulingStatusResponse(BaseModel):
    request: SchedulingRequestResponse


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

    slot_id: str | None = None
    poll_option_id: str | None = None
    handoff_to_calendar: bool | None = None


class SchedulingSummaryResponse(BaseModel):
    request: SchedulingRequestResponse
    poll_summary: PollResultSummaryResponse


class SchedulingCalendarActionResponse(BaseModel):
    request: SchedulingRequestResponse
    created_event_ids: list[str] = Field(default_factory=list)
    updated_slot_ids: list[str] = Field(default_factory=list)
    warnings: list[str] = Field(default_factory=list)


class SchedulingNotificationResponse(BaseModel):
    id: str
    request_id: str
    participant_id: str | None = None
    event_kind: str
    channel: str
    recipient: str | None = None
    status: str
    payload: dict[str, Any] = Field(default_factory=dict)
    error: str | None = None
    sent_at: datetime | None = None
    created_at: datetime
    updated_at: datetime
    metadata: dict[str, Any] = Field(default_factory=dict)


class SchedulingNotificationListResponse(BaseModel):
    notifications: list[SchedulingNotificationResponse] = Field(default_factory=list)


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

    event_kind: Literal["invitation", "reminder", "decision", "cancellation"]
    channel: str = Field(default="mail", max_length=40)
    metadata: dict[str, Any] = Field(default_factory=dict)