from __future__ import annotations

from datetime import date, datetime
from typing import Any, Literal, Optional

from pydantic import BaseModel, Field, field_validator


Weekday = Literal[0, 1, 2, 3, 4, 5, 6]  # Mon=0 .. Sun=6


class SetupPasswordRequest(BaseModel):
    password: str = Field(min_length=4, max_length=128)


class LoginRequest(BaseModel):
    password: str


class TokenResponse(BaseModel):
    access_token: str
    token_type: str = "bearer"
    needs_setup: bool = False
    onboarded: bool = False


class StatusResponse(BaseModel):
    has_password: bool
    onboarded: bool
    phase: str = "active"


class OnboardingRequest(BaseModel):
    one_rm_kg: float = Field(gt=0)
    training_weekdays: list[int] = Field(min_length=3, max_length=3)
    start_date: date

    @field_validator("training_weekdays")
    @classmethod
    def validate_days(cls, v: list[int]) -> list[int]:
        if len(set(v)) != 3:
            raise ValueError("Нужно выбрать 3 разных дня")
        for d in v:
            if d < 0 or d > 6:
                raise ValueError("День недели должен быть 0–6")
        sorted_days = sorted(v)
        # check circular gap of at least 1 day between consecutive selected days
        for i in range(3):
            a = sorted_days[i]
            b = sorted_days[(i + 1) % 3]
            if i < 2:
                gap = b - a - 1
            else:
                gap = (a + 7) - b - 1
            if gap < 1:
                raise ValueError("Между выбранными днями нужен минимум 1 день перерыва")
        return sorted(v)


class ProfileResponse(BaseModel):
    one_rm_kg: Optional[float]
    training_weekdays: Optional[list[int]]
    start_date: Optional[date]
    onboarded: bool
    phase: str
    rest_until: Optional[datetime]
    probe_available_at: Optional[datetime]
    cycle_number: int
    rest_countdown_seconds: Optional[int] = None
    can_probe: bool = False


class SetResponse(BaseModel):
    id: int
    set_index: int
    target_percent: Optional[float]
    target_reps: Optional[int]
    target_weight_kg: Optional[float]
    is_failure: bool
    completed: bool
    actual_reps: Optional[int]
    actual_weight_kg: Optional[float]


class ExerciseResponse(BaseModel):
    id: int
    order_index: int
    name: str
    kind: str
    prescribed_weight_kg: Optional[float]
    weight_locked: bool
    needs_weight_input: bool
    pending_prompt: Optional[str]
    weight_step_kg: float = 1.25
    sets: list[SetResponse]


class WorkoutSummary(BaseModel):
    id: int
    cycle_number: int
    week_number: int
    day_index: int
    scheduled_date: date
    status: str
    exercise_count: int = 0


class WorkoutDetail(BaseModel):
    id: int
    cycle_number: int
    week_number: int
    day_index: int
    scheduled_date: date
    status: str
    started_at: Optional[datetime]
    paused_at: Optional[datetime]
    completed_at: Optional[datetime]
    current_exercise_index: int
    current_set_index: int
    rest_started_at: Optional[datetime]
    rest_elapsed_seconds: int = 0
    can_start: bool = False
    can_resume: bool = False
    pause_expires_at: Optional[datetime] = None
    exercises: list[ExerciseResponse]


class CalendarResponse(BaseModel):
    year: int
    month: int
    workouts: list[WorkoutSummary]
    profile: ProfileResponse


class CompleteSetRequest(BaseModel):
    actual_reps: Optional[int] = None
    actual_weight_kg: Optional[float] = None


class SetWeightRequest(BaseModel):
    weight_kg: float = Field(gt=0)


class AdjustSetRequest(BaseModel):
    actual_weight_kg: float = Field(gt=0)
    actual_reps: int = Field(ge=0)


class PromptChoiceRequest(BaseModel):
    choice: Literal["easy_yes", "easy_no"]
    weight_kg: Optional[float] = None
    increase_kg: Optional[float] = None
    decrease_kg: Optional[float] = None


class StartRestRequest(BaseModel):
    rest_days: int = Field(ge=3, le=5)


class ProbeRequest(BaseModel):
    one_rm_kg: float = Field(gt=0)
    start_date: date
    training_weekdays: Optional[list[int]] = None


class ExportResponse(BaseModel):
    version: int = 1
    exported_at: datetime
    data: dict[str, Any]


class ImportRequest(BaseModel):
    version: int
    data: dict[str, Any]


class MessageResponse(BaseModel):
    message: str
    workout: Optional[WorkoutDetail] = None
    profile: Optional[ProfileResponse] = None


class MoveWorkoutRequest(BaseModel):
    scheduled_date: date


class TrainingDaysRequest(BaseModel):
    training_weekdays: list[int] = Field(min_length=3, max_length=3)

    @field_validator("training_weekdays")
    @classmethod
    def validate_days(cls, v: list[int]) -> list[int]:
        return OnboardingRequest.validate_days(v)