from __future__ import annotations

import logging
from collections.abc import Callable
from dataclasses import dataclass, replace
from inspect import Parameter, signature

from core.models import Scene, Task, utc_now
from runtime.context import TaskContext
from runtime.executor import Executor
from runtime.planner import PlannedStep, Planner
from semantic.models import SemanticScene
from skills_learning.config import (
    SkillAuthoringConfig,
    load_config as load_skill_authoring_config,
)
from skills_learning.embeddings import EmbeddingClient, embed_skill_text
from skills_learning.models import skill_embedding_text
from skills_learning.store import SkillStore, get_default_store
from skills_learning.synthesis import synthesize_flow_skill
from skills_learning.versioning import store_synthesized_skill
from storage.task_metadata import TaskMetadataStore
from storage.timeline import Timeline
from tools.describe_screen import describe_screen
from tools.screenshot import take_screenshot
from world.config import WorldConfig, load_config as load_world_config
from world.model import TaskWorldView, WorldModel

logger = logging.getLogger(__name__)


@dataclass
class TaskRunnerConfig:
    max_steps: int = 20


Observer = Callable[[str], Scene]
ScreenshotProvider = Callable[[str], bytes]
TaskSucceededHook = Callable[[str, str, Timeline], None]


class TaskRunner:
    def __init__(
        self,
        *,
        planner: Planner | None = None,
        executor: Executor | None = None,
        timeline: Timeline | None = None,
        metadata_store: TaskMetadataStore | None = None,
        config: TaskRunnerConfig | None = None,
        observer: Observer | None = None,
        screenshot_provider: ScreenshotProvider | None = None,
        world_model: WorldModel | None = None,
        world_config: WorldConfig | None = None,
        on_task_succeeded: TaskSucceededHook | None = None,
        skill_authoring_config: SkillAuthoringConfig | None = None,
        skill_store: SkillStore | None = None,
        skill_embedding_client: EmbeddingClient | None = None,
    ) -> None:
        self.planner = planner or Planner()
        self.executor = executor or Executor()
        self.timeline = timeline
        self.metadata_store = metadata_store
        self.config = config or TaskRunnerConfig()
        self.observer = observer or (lambda device_id: describe_screen(device_id))
        self.screenshot_provider = screenshot_provider or (
            lambda device_id: take_screenshot(device_id)
        )
        self.world_config = world_config or load_world_config()
        if world_model is not None:
            self.world_model = world_model
        elif self.world_config.enabled:
            self.world_model = WorldModel(config=self.world_config)
        else:
            self.world_model = None
        self.skill_authoring_config = (
            skill_authoring_config or load_skill_authoring_config()
        )
        self.skill_store = skill_store
        self.skill_embedding_client = skill_embedding_client
        if on_task_succeeded is not None:
            self.on_task_succeeded = on_task_succeeded
        elif self.skill_authoring_config.enabled:
            self.on_task_succeeded = self._default_task_succeeded_hook
        else:
            self.on_task_succeeded = None

    def run(self, task: Task) -> Task:
        context = TaskContext(task_id=task.id, goal=task.goal)
        world_handle = self._start_world_view(task.id)
        if world_handle is not None:
            context.world = world_handle.state
        self._update_task(task, status="running")

        for _ in range(self.config.max_steps):
            scene = self.observer(task.device_id)
            context.add_scene(scene)
            steps = self._plan(task.goal, scene, context)
            if not steps or self.planner.goal_reached(
                goal=task.goal,
                scene=scene,
                context=context,
            ):
                return self._complete_task(task)

            for step in steps:
                executable_step = self._step_for_device(step, task.device_id)
                result = self.executor.execute(
                    executable_step,
                    context=context,
                )
                context.add_step_result(result)
                self._record_step_result(world_handle, context, task, scene, step, result)
                if not result.success:
                    self._update_task(
                        task,
                        status="failed",
                        completed=True,
                        failure_reason=result.error or "step failed",
                    )
                    return task

        self._update_task(
            task,
            status="failed",
            completed=True,
            failure_reason=f"max steps exceeded: {self.config.max_steps}",
        )
        return task

    def _start_world_view(self, task_id: str) -> TaskWorldView | None:
        """Start (or resume) this task's isolated `WorldModel` handle, if enabled.

        Shared by `run()` and by any other driver (e.g. `CollaborativeTaskRunner`)
        that composes this `TaskRunner` for its world-model bookkeeping.
        """
        if self.world_model is None:
            return None
        return self.world_model.start_task(task_id)

    def _record_step_result(
        self,
        world_handle: TaskWorldView | None,
        context: TaskContext,
        task: Task,
        scene: Scene,
        step: PlannedStep,
        result: object,
    ) -> None:
        """Record one executed step's bookkeeping: world-model observe + timeline append.

        Shared by `run()` and by any other driver (e.g. `CollaborativeTaskRunner`)
        that executes steps outside of this class's own loop, so the two paths
        cannot drift apart on what gets recorded for a step.
        """
        self._update_world(world_handle, context, scene, step, result)
        self._append_timeline(task, scene, step, result)

    def _complete_task(self, task: Task) -> Task:
        self._update_task(task, status="completed", completed=True)
        self._notify_task_succeeded(task)
        return task

    def _notify_task_succeeded(self, task: Task) -> None:
        if self.on_task_succeeded is None or self.timeline is None:
            return
        try:
            self.on_task_succeeded(task.id, task.goal, self.timeline)
        except Exception as exc:
            logger.info("task succeeded hook failed: %s", exc)

    def _default_task_succeeded_hook(
        self,
        task_id: str,
        goal: str,
        timeline: Timeline,
    ) -> None:
        store = self.skill_store or get_default_store()
        candidate = synthesize_flow_skill(
            goal,
            timeline,
            task_id=task_id,
            store=store,
        )
        stored = store_synthesized_skill(store, candidate).skill
        vector = embed_skill_text(
            skill_embedding_text(stored),
            client=self.skill_embedding_client,
            config=self.skill_authoring_config,
        )
        if vector is not None:
            store.store_embedding(
                stored,
                vector,
                model_name=self.skill_authoring_config.embedding_model,
            )

    def _plan(
        self,
        goal: str,
        scene: Scene,
        context: TaskContext,
    ) -> list[PlannedStep]:
        if context.world is not None and self._planner_accepts_world():
            return self.planner.plan(
                goal=goal,
                scene=scene,
                context=context,
                world=context.world,
            )
        return self.planner.plan(goal=goal, scene=scene, context=context)

    def _planner_accepts_world(self) -> bool:
        try:
            parameters = signature(self.planner.plan).parameters
        except (TypeError, ValueError):
            return True
        return "world" in parameters or any(
            parameter.kind is Parameter.VAR_KEYWORD
            for parameter in parameters.values()
        )

    def _update_world(
        self,
        world_handle: TaskWorldView | None,
        context: TaskContext,
        scene: Scene,
        step: PlannedStep,
        result: object,
    ) -> None:
        if world_handle is None:
            return
        world_handle.observe(
            scene,
            self._semantic_scene_from_result(result),
            step,
            result,  # type: ignore[arg-type]
        )
        context.world = world_handle.state

    def _semantic_scene_from_result(self, result: object) -> SemanticScene | None:
        value = getattr(result, "result", None)
        if isinstance(value, dict):
            semantic_scene = value.get("semantic_scene")
            if isinstance(semantic_scene, SemanticScene):
                return semantic_scene
        return None

    def _append_timeline(
        self,
        task: Task,
        scene: Scene,
        step: PlannedStep,
        result: object,
    ) -> None:
        if not self.timeline:
            return
        try:
            screenshot = self.screenshot_provider(task.device_id)
        except Exception:
            screenshot = None
        self.timeline.append(
            task_id=task.id,
            scene=scene.to_dict(),
            prompt=task.goal,
            tool_call={
                "action": step.action,
                "description": step.description,
                "args": step.args,
            },
            result=result.to_dict() if hasattr(result, "to_dict") else {"result": result},
            screenshot=screenshot,
        )

    def _step_for_device(self, step: PlannedStep, device_id: str) -> PlannedStep:
        device_scoped_actions = {
            "take_screenshot",
            "screenshot",
            "tap",
            "swipe",
            "input_text",
            "launch_app",
            "terminate_app",
            "get_ui_tree",
            "ui_tree",
            "describe_screen",
            "describe_screen_semantic",
            "find_text_on_screen",
            "find_icon_on_screen",
        }
        if step.action not in device_scoped_actions or "device_id" in step.args:
            return step
        return replace(step, args={**step.args, "device_id": device_id})

    def _update_task(
        self,
        task: Task,
        *,
        status: str,
        completed: bool = False,
        failure_reason: str | None = None,
    ) -> None:
        task.status = status  # type: ignore[assignment]
        task.updated_at = utc_now()
        if completed:
            task.completed_at = utc_now()
        task.failure_reason = failure_reason
        if self.metadata_store:
            self.metadata_store.update_task(
                task.id,
                status=task.status,
                completed=completed,
                failure_reason=failure_reason,
            )