from __future__ import annotations

from pathlib import Path

from pydantic import BaseModel, Field, model_validator
from pydantic_settings import BaseSettings, PydanticBaseSettingsSource, SettingsConfigDict, YamlConfigSettingsSource
from pydantic_settings.sources import EnvSettingsSource

from tracker.constants import DisplayDistanceUnit, DisplayWeightUnit

_TRACKER_REPO_ROOT = Path(__file__).resolve().parent.parent
_CONFIG_YAML_PATH = _TRACKER_REPO_ROOT / "config.yaml"


class DashboardLogin(BaseModel):
    """Small, explicit dashboard account for HF/demo deployments."""

    label: str
    email: str = Field(min_length=1)
    password: str = Field(min_length=1)
    role: str | None = None
    notes: list[str] = Field(default_factory=list)


class TrackerConfig(BaseSettings):
    """Tracker app configuration: config.yaml first, then TRACKER_* environment overrides (HF Secrets)."""

    model_config = SettingsConfigDict(env_prefix="TRACKER_", extra="ignore")

    parser_data_dir: str
    tracker_db_path: str
    google_credentials_path: str
    google_token_path: str
    default_calendar_id: str
    chores_calendar_id: str | None = None
    workout_calendar_id: str | None = None
    tracker_app_url: str = "http://127.0.0.1:8020"
    host: str
    port: int
    active_program_id: int | None = None
    agent_profile_path: str = "agent_profile.yaml"
    agent_api_key: str | None = None
    dashboard_password: str | None = None
    dashboard_logins: list[DashboardLogin] = Field(default_factory=list)
    session_secret: str | None = None
    display_weight_unit: DisplayWeightUnit = DisplayWeightUnit.KG
    display_distance_unit: DisplayDistanceUnit = DisplayDistanceUnit.KM
    calibration_dumbbell_bench_lb_per_hand: float | None = None
    calibration_dumbbell_squat_lb_per_hand: float | None = None
    dumbbell_weight_quantum_lb: float = 5.0

    @model_validator(mode="after")
    def validate_dashboard_session(self) -> TrackerConfig:
        if self.dashboard_password or self.dashboard_logins:
            if not self.session_secret or len(self.session_secret) < 16:
                msg = (
                    "session_secret must be set to at least 16 characters when "
                    "dashboard_password or dashboard_logins is set"
                )
                raise ValueError(msg)
        return self

    @property
    def user_db_path(self) -> Path:
        return Path(self.parser_data_dir) / "user.db"

    @property
    def query_db_path(self) -> Path:
        return Path(self.parser_data_dir) / "web_query.db"

    @property
    def cache_db_path(self) -> Path:
        return Path(self.parser_data_dir) / "web_cache.db"

    @property
    def tracker_db_full_path(self) -> Path:
        path = Path(self.tracker_db_path)
        return path if path.is_absolute() else _TRACKER_REPO_ROOT / path

    @property
    def agent_profile_resolved_path(self) -> Path:
        path = Path(self.agent_profile_path)
        return path if path.is_absolute() else _TRACKER_REPO_ROOT / path

    @classmethod
    def settings_customise_sources(
        cls,
        settings_cls: type[BaseSettings],
        init_settings: PydanticBaseSettingsSource,
        env_settings: PydanticBaseSettingsSource,
        dotenv_settings: PydanticBaseSettingsSource,
        file_secret_settings: PydanticBaseSettingsSource,
    ) -> tuple[PydanticBaseSettingsSource, ...]:
        return (
            init_settings,
            EnvSettingsSource(settings_cls),
            YamlConfigSettingsSource(settings_cls, yaml_file=str(_CONFIG_YAML_PATH)),
        )


def load_config() -> TrackerConfig:
    return TrackerConfig()