"""One-task run orchestration.

Flow: lock target repo → resolve tool profile / budget from instance
manifest → snapshot HEAD → persona bundle → prompt → agentic session →
verify a new commit exists → kaizen metrics + hub progress event
(+ task close). The run *fails* if the session pushed anywhere or left
the repo dirty in a way it should not — the worker never pushes;
publishing is a separate, explicitly-granted lane.
"""

from __future__ import annotations

import subprocess
import time
from dataclasses import dataclass
from pathlib import Path

from agent_harness import hub, metrics
from agent_harness.manifest import resolve_run_policy
from agent_harness.persona import load_persona_bundle
from agent_harness.profiles import UnknownToolProfileError, get_profile
from agent_harness.taskspec import TaskSpec

PROMPT_TEMPLATE = """\
You are an unattended executor session (agent persona below, if any).
Operating rules, non-negotiable:
- Work ONLY inside the current repository working directory.
- Green/Blue lane: file edits and local git add/commit only. Never push,
  never touch the network, never run destructive commands.
- Tool profile for this run: {tool_profile} (lane={lane}).
- Bounded effort: complete the single task below, commit with a clear
  message, then stop. If the task cannot be completed, commit nothing and
  say why in your final output.

{persona}

## Task: {title}

{description}
"""


@dataclass
class RunResult:
    ok: bool
    committed: bool
    head_before: str
    head_after: str
    persona_source: str
    session_output: str
    reason: str = ""
    tool_profile: str = ""
    budget_tokens: int | None = None
    tokens_spent: int | None = None
    execution_time_s: float = 0.0


def _git(repo: Path, *args: str) -> str:
    result = subprocess.run(
        ["git", "-C", str(repo), *args],
        capture_output=True,
        text=True,
        timeout=60,
    )
    if result.returncode != 0:
        raise RuntimeError(f"git {' '.join(args)} failed: {result.stderr.strip()}")
    return result.stdout.strip()


def run_task(
    spec: TaskSpec,
    adapter=None,
    report_to_hub: bool = True,
    write_metrics: bool = True,
) -> RunResult:
    try:
        profile_name, budget_tokens, lane, blueprint = resolve_run_policy(
            spec.target_repo, spec.agent
        )
        profile = get_profile(profile_name)
    except UnknownToolProfileError as exc:
        return RunResult(
            ok=False,
            committed=False,
            head_before="",
            head_after="",
            persona_source="none",
            session_output="",
            reason=f"refused: {exc}",
            tool_profile="",
            budget_tokens=None,
        )
    except Exception as exc:
        return RunResult(
            ok=False,
            committed=False,
            head_before="",
            head_after="",
            persona_source="none",
            session_output="",
            reason=f"manifest resolution failed: {exc}",
            tool_profile="",
            budget_tokens=None,
        )

    if adapter is None:
        from agent_harness.adapter import AgenticClaudeCodeAdapter

        adapter = AgenticClaudeCodeAdapter(
            workdir=spec.target_repo,
            tool_profile=profile,
        )

    head_before = _git(spec.target_repo, "rev-parse", "HEAD")
    persona, persona_source = load_persona_bundle(blueprint, spec.target_repo)
    prompt = PROMPT_TEMPLATE.format(
        persona=persona or "(no persona bundle available for this run)",
        title=spec.title,
        description=spec.description,
        tool_profile=profile.name,
        lane=lane or profile.lane,
    )

    from llm_connect.models import BudgetTracker, RunConfig

    budget_tracker = BudgetTracker(total=budget_tokens) if budget_tokens else None
    config = RunConfig(
        timeout_seconds=spec.timeout_seconds,
        skip_if_exists=False,
        budget_tracker=budget_tracker,
    )

    started = time.monotonic()
    try:
        response = adapter.execute_prompt(prompt, config)
        session_output = response.content
        session_ok = True
        reason = ""
    except Exception as exc:  # adapter / budget failures must still be reported
        session_output = ""
        session_ok = False
        reason = f"session failed: {exc}"
    execution_time_s = time.monotonic() - started

    head_after = _git(spec.target_repo, "rev-parse", "HEAD")
    committed = head_after != head_before
    ok = session_ok and committed
    if session_ok and not committed:
        reason = "session completed without committing"

    tokens_spent = budget_tracker.spent if budget_tracker is not None else None

    result = RunResult(
        ok=ok,
        committed=committed,
        head_before=head_before,
        head_after=head_after,
        persona_source=persona_source,
        session_output=session_output,
        reason=reason,
        tool_profile=profile.name,
        budget_tokens=budget_tokens,
        tokens_spent=tokens_spent,
        execution_time_s=execution_time_s,
    )

    if write_metrics:
        try:
            metrics.record_execution(
                spec.target_repo,
                spec.agent,
                success=ok,
                execution_time_s=execution_time_s,
                tokens=tokens_spent,
                committed=committed,
                head_after=head_after,
                reason=reason or None,
                metadata={
                    "task_title": spec.title,
                    "tool_profile": profile.name,
                    "labels": list(spec.labels),
                    "completion_event_type": spec.completion_event_type,
                },
            )
        except OSError:
            pass  # metrics must not block run completion reporting

    if report_to_hub:
        detail = {
            "repo": spec.target_repo.name,
            "task_title": spec.title,
            "agent": spec.agent,
            "labels": spec.labels,
            "persona_source": persona_source,
            "committed": committed,
            "head_after": head_after,
            "ok": ok,
            "reason": reason,
            "tool_profile": profile.name,
            "budget_tokens": budget_tokens,
            "tokens_spent": tokens_spent,
            "execution_time_s": round(execution_time_s, 3),
        }
        hub.post_progress_event(
            summary=f"executor run: {spec.title} ({'ok' if ok else 'failed'})",
            event_type=spec.completion_event_type,
            detail=detail,
            task_id=spec.hub_task_id,
        )
        if tokens_spent is not None or budget_tokens is not None:
            hub.post_token_event(
                repo=spec.target_repo.name,
                tokens=tokens_spent or 0,
                budget=budget_tokens,
                agent=spec.agent,
                ok=ok,
                detail={"task_title": spec.title, "tool_profile": profile.name},
            )
        if ok and spec.hub_task_id:
            hub.close_task(spec.hub_task_id)

    return result