"""LED picture target — sends color strip sources to an LED device."""

from dataclasses import dataclass, field
from datetime import datetime
from typing import List, Optional

from wled_controller.storage.picture_target import PictureTarget

DEFAULT_STATE_CHECK_INTERVAL = 30  # seconds


@dataclass
class TargetSegment:
    """Maps a color strip source to a pixel range on the LED device.

    ``start`` is inclusive, ``end`` is exclusive.  When a target has a single
    segment with ``end == 0`` the range auto-fits to the full device LED count.
    """

    color_strip_source_id: str = ""
    start: int = 0
    end: int = 0
    reverse: bool = False

    def to_dict(self) -> dict:
        return {
            "color_strip_source_id": self.color_strip_source_id,
            "start": self.start,
            "end": self.end,
            "reverse": self.reverse,
        }

    @staticmethod
    def from_dict(d: dict) -> "TargetSegment":
        return TargetSegment(
            color_strip_source_id=d.get("color_strip_source_id", ""),
            start=d.get("start", 0),
            end=d.get("end", 0),
            reverse=d.get("reverse", False),
        )


@dataclass
class WledPictureTarget(PictureTarget):
    """LED picture target — pairs an LED device with one or more ColorStripSources.

    Each segment maps a ColorStripSource to a pixel range on the device.
    Gaps between segments stay black.  A single segment with ``end == 0``
    auto-fits to the full device LED count.
    """

    device_id: str = ""
    segments: List[TargetSegment] = field(default_factory=list)
    fps: int = 30                   # target send FPS (1-90)
    keepalive_interval: float = 1.0 # seconds between keepalive sends when screen is static
    state_check_interval: int = DEFAULT_STATE_CHECK_INTERVAL

    def register_with_manager(self, manager) -> None:
        """Register this WLED target with the processor manager."""
        if self.device_id:
            manager.add_target(
                target_id=self.id,
                device_id=self.device_id,
                segments=[s.to_dict() for s in self.segments],
                fps=self.fps,
                keepalive_interval=self.keepalive_interval,
                state_check_interval=self.state_check_interval,
            )

    def sync_with_manager(self, manager, *, settings_changed: bool,
                          segments_changed: bool = False,
                          device_changed: bool = False) -> None:
        """Push changed fields to the processor manager."""
        if settings_changed:
            manager.update_target_settings(self.id, {
                "fps": self.fps,
                "keepalive_interval": self.keepalive_interval,
                "state_check_interval": self.state_check_interval,
            })
        if segments_changed:
            manager.update_target_segments(self.id, [s.to_dict() for s in self.segments])
        if device_changed:
            manager.update_target_device(self.id, self.device_id)

    def update_fields(self, *, name=None, device_id=None, segments=None,
                      fps=None, keepalive_interval=None, state_check_interval=None,
                      description=None, **_kwargs) -> None:
        """Apply mutable field updates for WLED targets."""
        super().update_fields(name=name, description=description)
        if device_id is not None:
            self.device_id = device_id
        if segments is not None:
            self.segments = [
                TargetSegment.from_dict(s) if isinstance(s, dict) else s
                for s in segments
            ]
        if fps is not None:
            self.fps = fps
        if keepalive_interval is not None:
            self.keepalive_interval = keepalive_interval
        if state_check_interval is not None:
            self.state_check_interval = state_check_interval

    @property
    def has_picture_source(self) -> bool:
        return any(s.color_strip_source_id for s in self.segments)

    def to_dict(self) -> dict:
        """Convert to dictionary."""
        d = super().to_dict()
        d["device_id"] = self.device_id
        d["segments"] = [s.to_dict() for s in self.segments]
        d["fps"] = self.fps
        d["keepalive_interval"] = self.keepalive_interval
        d["state_check_interval"] = self.state_check_interval
        return d

    @classmethod
    def from_dict(cls, data: dict) -> "WledPictureTarget":
        """Create from dictionary with backward compatibility."""
        # Migrate old single-source format to segments
        if "segments" in data:
            segments = [TargetSegment.from_dict(s) for s in data["segments"]]
        elif "color_strip_source_id" in data:
            css_id = data.get("color_strip_source_id", "")
            skip_start = data.get("led_skip_start", 0)
            skip_end = data.get("led_skip_end", 0)
            if css_id:
                segments = [TargetSegment(
                    color_strip_source_id=css_id,
                    start=skip_start,
                    end=0,  # auto-fit; skip_end handled by processor
                )]
            else:
                segments = []
        else:
            segments = []

        return cls(
            id=data["id"],
            name=data["name"],
            target_type="led",
            device_id=data.get("device_id", ""),
            segments=segments,
            fps=data.get("fps", 30),
            keepalive_interval=data.get("keepalive_interval", data.get("standby_interval", 1.0)),
            state_check_interval=data.get("state_check_interval", DEFAULT_STATE_CHECK_INTERVAL),
            description=data.get("description"),
            created_at=datetime.fromisoformat(data.get("created_at", datetime.utcnow().isoformat())),
            updated_at=datetime.fromisoformat(data.get("updated_at", datetime.utcnow().isoformat())),
        )