"""
oO simulation runner — compares two recommendation policies.

Judge modes:
  rule         Deterministic persona-based rules (default, no external deps)
  llm          Claude Haiku via Anthropic API (requires ANTHROPIC_API_KEY)
  claude-code  Two-phase: Claude Code acts as the judge (you are the judge)

Usage — rule/llm (single pass):
  python runner.py --n-users 5 --n-rounds 10 --no-llm
  python runner.py --n-users 5 --n-rounds 10

Usage — claude-code judge (two phases):
  # Phase 1: score candidates, write judgment requests
  python runner.py --judge claude-code --phase score \\
      --n-users 5 --n-rounds 10 --out /tmp/oo-cc-sim.json

  # (Claude Code reads /tmp/oo-cc-sim-requests.json and writes /tmp/oo-cc-sim-responses.json)

  # Phase 2: apply responses, run rewards, produce results
  python runner.py --judge claude-code --phase reward --plan /tmp/oo-cc-sim-plan.json \\
      --out /tmp/oo-cc-sim.json
"""

from __future__ import annotations

import argparse
import json
import random
import sys
import time
import uuid
from pathlib import Path

sys.path.insert(0, str(Path(__file__).parent))

import httpx

from llm_judge import ACTIONS, infer_reward, judge
from personas import PERSONAS, Persona
from task_generator import generate_task_pool

POLICY_SCORE_ENDPOINTS: dict[str, str] = {
    "linucb-v1": "/score",
    "egreedy-v1": "/score/egreedy",
}
POLICY_REWARD_ENDPOINTS: dict[str, str] = {
    "linucb-v1": "/reward",
    "egreedy-v1": "/reward/egreedy",
}


def _call_score(
    client: httpx.Client, ml_url: str, policy: str,
    user_id: str, tasks: list[dict], hour: int, dow: int,
) -> dict | None:
    endpoint = POLICY_SCORE_ENDPOINTS.get(policy, "/score")
    body = {
        "user_id": user_id,
        "candidates": [
            {
                "id": t["id"], "content": t["content"], "source": t["source"],
                "source_id": None,
                "features": {
                    "hour_of_day": hour,
                    "is_overdue": t["features"]["is_overdue"],
                    "task_age_days": t["features"]["task_age_days"],
                    "priority": t["features"]["priority"],
                },
            }
            for t in tasks
        ],
        "context": {"hour_of_day": hour, "day_of_week": dow},
    }
    try:
        r = client.post(f"{ml_url}{endpoint}", json=body, timeout=5.0)
        r.raise_for_status()
        return r.json()
    except Exception as e:
        print(f"  [warn] score {policy}: {e}", file=sys.stderr)
        return None


def _call_reward(
    client: httpx.Client, ml_url: str, policy: str,
    user_id: str, tip_id: str, reward: float, features: dict,
    day_of_week: int = 0,
) -> None:
    endpoint = POLICY_REWARD_ENDPOINTS.get(policy, "/reward")
    try:
        client.post(
            f"{ml_url}{endpoint}",
            json={"user_id": user_id, "tip_id": tip_id, "reward": reward,
                  "features": features, "day_of_week": day_of_week},
            timeout=5.0,
        )
    except Exception as e:
        print(f"  [warn] reward {policy}: {e}", file=sys.stderr)


# ── Standard single-pass runner (rule / llm modes) ─────────────────────────

def run_simulation(
    n_users: int, n_rounds: int, tasks_per_round: int,
    ml_url: str, policies: list[str], use_llm: bool, seed: int,
) -> dict:
    rng = random.Random(seed)
    run_id = str(uuid.uuid4())[:8]
    started_at = time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())

    user_personas = [
        (f"sim-{run_id}-u{i}", PERSONAS[i % len(PERSONAS)])
        for i in range(n_users)
    ]

    acc: dict[str, dict] = {
        p: {
            "total_reward": 0.0, "n_pulls": 0,
            "cumulative_rewards": [],
            "action_counts": {a: 0 for a in ACTIONS},
        }
        for p in policies
    }
    events: list[dict] = []

    with httpx.Client(trust_env=False) as client:
        for rnd in range(n_rounds):
            hour = rng.randint(6, 22)
            dow = rng.randint(0, 6)
            round_rewards = {p: 0.0 for p in policies}

            for user_id, persona in user_personas:
                seed_tasks = rnd * 997 + abs(hash(user_id)) % 997
                tasks = generate_task_pool(n=tasks_per_round, seed=seed_tasks)

                for policy in policies:
                    p_user = f"{user_id}-{policy}"
                    scored = _call_score(client, ml_url, policy, p_user, tasks, hour, dow)
                    if not scored:
                        continue
                    tip_id = scored.get("tip_id")
                    tip = next((t for t in tasks if t["id"] == tip_id), None)
                    if not tip:
                        continue

                    action, dwell_ms, reward = judge(persona, tip, hour, dow, rng, use_llm=use_llm)
                    _call_reward(client, ml_url, policy, p_user, tip_id, reward, {
                        "hour_of_day": hour,
                        "is_overdue": tip["features"]["is_overdue"],
                        "task_age_days": tip["features"]["task_age_days"],
                        "priority": tip["features"]["priority"],
                    }, day_of_week=dow)

                    acc[policy]["total_reward"] += reward
                    acc[policy]["n_pulls"] += 1
                    acc[policy]["action_counts"][action] += 1
                    round_rewards[policy] += reward
                    events.append({
                        "round": rnd, "user_id": user_id, "persona": persona.name,
                        "policy": policy, "tip_content": tip["content"],
                        "priority": tip["features"]["priority"],
                        "is_overdue": tip["features"]["is_overdue"],
                        "action": action, "dwell_ms": dwell_ms, "reward": reward,
                        "hour": hour, "day_of_week": dow,
                    })

            for p in policies:
                prev = acc[p]["cumulative_rewards"][-1] if acc[p]["cumulative_rewards"] else 0.0
                acc[p]["cumulative_rewards"].append(prev + round_rewards[p])

            mode = "llm" if use_llm else "rule"
            print(f"  Round {rnd+1:>3}/{n_rounds} [{mode}]  " + "  ".join(
                f"{p}={acc[p]['cumulative_rewards'][-1]:+.2f}" for p in policies
            ))

    return _build_result(run_id, started_at, policies, acc, events,
                         n_users, n_rounds, tasks_per_round, use_llm, seed)


# ── Claude Code judge — phase 1: score ─────────────────────────────────────

def run_score_phase(
    n_users: int, n_rounds: int, tasks_per_round: int,
    ml_url: str, policies: list[str], seed: int, out_path: str,
) -> None:
    """Score all candidates and write judgment requests for Claude Code."""
    rng = random.Random(seed)
    run_id = str(uuid.uuid4())[:8]
    started_at = time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())

    user_personas = [
        (f"sim-{run_id}-u{i}", PERSONAS[i % len(PERSONAS)])
        for i in range(n_users)
    ]

    plan_rounds: list[dict] = []
    judgment_requests: list[dict] = []

    print(f"[Phase 1] Scoring {n_rounds} rounds × {n_users} users × {len(policies)} policies…")

    with httpx.Client(trust_env=False) as client:
        for rnd in range(n_rounds):
            hour = rng.randint(6, 22)
            dow = rng.randint(0, 6)
            round_sessions: list[dict] = []

            for user_id, persona in user_personas:
                seed_tasks = rnd * 997 + abs(hash(user_id)) % 997
                tasks = generate_task_pool(n=tasks_per_round, seed=seed_tasks)

                for policy in policies:
                    p_user = f"{user_id}-{policy}"
                    scored = _call_score(client, ml_url, policy, p_user, tasks, hour, dow)
                    if not scored:
                        continue
                    tip_id = scored.get("tip_id")
                    tip = next((t for t in tasks if t["id"] == tip_id), None)
                    if not tip:
                        continue

                    req_id = f"r{rnd}_{user_id.split('-')[-1]}_{policy}"
                    round_sessions.append({
                        "req_id": req_id,
                        "p_user": p_user,
                        "policy": policy,
                        "user_id": user_id,
                        "persona_name": persona.name,
                        "tip_id": tip_id,
                        "tip_features": tip["features"],
                        "tip_content": tip["content"],
                        "ml_score": scored.get("score"),
                    })

                    judgment_requests.append({
                        "id": req_id,
                        "round": rnd,
                        "hour": hour,
                        "day_of_week": dow,
                        "policy": policy,
                        "persona_name": persona.name,
                        "persona_description": persona.description,
                        "tip_content": tip["content"],
                        "priority": tip["features"]["priority"],
                        "is_overdue": tip["features"]["is_overdue"],
                        "age_days": tip["features"]["task_age_days"],
                        "ml_score": scored.get("score"),
                    })

            plan_rounds.append({
                "round": rnd, "hour": hour, "dow": dow,
                "sessions": round_sessions,
            })
            print(f"  Round {rnd+1:>3}/{n_rounds}: {len(round_sessions)} sessions scored")

    plan = {
        "run_id": run_id,
        "started_at": started_at,
        "config": {
            "n_users": n_users, "n_rounds": n_rounds,
            "tasks_per_round": tasks_per_round, "policies": policies,
            "use_llm": False, "seed": seed,
        },
        "user_personas": [
            {"user_id": uid, "persona_name": p.name, "persona_description": p.description}
            for uid, p in user_personas
        ],
        "rounds": plan_rounds,
    }

    base = out_path.replace(".json", "")
    plan_path = f"{base}-plan.json"
    requests_path = f"{base}-requests.json"
    responses_path = f"{base}-responses.json"

    Path(plan_path).write_text(json.dumps(plan, indent=2))
    Path(requests_path).write_text(json.dumps(judgment_requests, indent=2))

    print()
    print("=" * 60)
    print(f"Phase 1 complete — {len(judgment_requests)} judgment requests.")
    print()
    print(f"  Requests : {requests_path}")
    print(f"  Plan     : {plan_path}")
    print()
    print('Claude Code: read the requests file, judge each tip for the persona,')
    print(f'then write your responses to: {responses_path}')
    print()
    print('Response format: { "<id>": "<action>" | { "action": "<action>", "dwell_ms": <int> } }')
    print('Valid actions: done | snooze | dismiss')
    print()
    print('For "done", optionally specify dwell_ms (ms between tip appearing and user acting):')
    print('  { "r0_u0_linucb-v1": { "action": "done", "dwell_ms": 45000 } }  # magic zone')
    print('  { "r0_u0_linucb-v1": "snooze" }  # plain string also ok (uses default 60s dwell for done)')
    print()
    print('Reward is inferred from action + dwell_ms:')
    print('  dismiss          → -1.0')
    print('  snooze           →  0.1')
    print('  done < 15s       → -0.3  (stale task)')
    print('  done 15s–2min    →  1.0  (magic!)')
    print('  done 2–10min     →  0.6  (good)')
    print('  done > 10min     →  0.3  (eventually)')
    print()
    print('Then run Phase 2:')
    print(f'  python runner.py --judge claude-code --phase reward \\')
    print(f'    --plan {plan_path} --out {out_path}')


# ── Claude Code judge — phase 2: reward ────────────────────────────────────

def run_reward_phase(plan_path: str, out_path: str, ml_url: str) -> dict:
    """Apply Claude Code judgments, send reward signals, compute metrics."""
    plan = json.loads(Path(plan_path).read_text())
    base = plan_path.replace("-plan.json", "")
    responses_path = f"{base}-responses.json"

    if not Path(responses_path).exists():
        print(f"ERROR: responses file not found: {responses_path}", file=sys.stderr)
        sys.exit(1)

    raw_responses = json.loads(Path(responses_path).read_text())

    # Responses can be either { id: "action" } or { id: { action, dwell_ms } }
    def _parse_response(v) -> tuple[str, int]:
        if isinstance(v, dict):
            return v["action"], int(v.get("dwell_ms", 60_000))
        return str(v), 60_000  # plain string → assume 60s dwell for "done"

    responses: dict[str, tuple[str, int]] = {k: _parse_response(v) for k, v in raw_responses.items()}

    invalid = {k: v[0] for k, v in responses.items() if v[0] not in ACTIONS}
    if invalid:
        print(f"ERROR: invalid actions in responses: {invalid}", file=sys.stderr)
        sys.exit(1)

    policies: list[str] = plan["config"]["policies"]
    acc: dict[str, dict] = {
        p: {
            "total_reward": 0.0, "n_pulls": 0,
            "cumulative_rewards": [],
            "action_counts": {a: 0 for a in ACTIONS},
        }
        for p in policies
    }
    events: list[dict] = []
    persona_map = {u["user_id"]: u["persona_name"] for u in plan["user_personas"]}
    missing_responses = 0

    print(f"[Phase 2] Applying {len(responses)} judgments → reward calls…")

    with httpx.Client(trust_env=False) as client:
        for rnd_data in plan["rounds"]:
            rnd = rnd_data["round"]
            round_rewards = {p: 0.0 for p in policies}

            for session in rnd_data["sessions"]:
                req_id = session["req_id"]
                resp = responses.get(req_id)
                if not resp:
                    print(f"  [warn] no response for {req_id}, defaulting to snooze")
                    action, dwell_ms = "snooze", 10_000
                    missing_responses += 1
                else:
                    action, dwell_ms = resp

                reward = infer_reward(action, dwell_ms)
                _call_reward(
                    client, ml_url, session["policy"], session["p_user"],
                    session["tip_id"], reward,
                    {"hour_of_day": rnd_data["hour"], **session["tip_features"]},
                    day_of_week=rnd_data["dow"],
                )

                p = session["policy"]
                acc[p]["total_reward"] += reward
                acc[p]["n_pulls"] += 1
                acc[p]["action_counts"][action] += 1
                round_rewards[p] += reward

                events.append({
                    "round": rnd,
                    "user_id": session["user_id"],
                    "persona": persona_map.get(session["user_id"], "?"),
                    "policy": p,
                    "tip_content": session["tip_content"],
                    "priority": session["tip_features"]["priority"],
                    "is_overdue": session["tip_features"]["is_overdue"],
                    "action": action,
                    "dwell_ms": dwell_ms,
                    "reward": reward,
                    "hour": rnd_data["hour"],
                    "day_of_week": rnd_data["dow"],
                })

            for p in policies:
                prev = acc[p]["cumulative_rewards"][-1] if acc[p]["cumulative_rewards"] else 0.0
                acc[p]["cumulative_rewards"].append(prev + round_rewards[p])

            print(f"  Round {rnd+1:>3}/{plan['config']['n_rounds']} [cc]  " + "  ".join(
                f"{p}={acc[p]['cumulative_rewards'][-1]:+.2f}" for p in policies
            ))

    if missing_responses:
        print(f"  [warn] {missing_responses} requests had no response (defaulted to snooze)")

    cfg = plan["config"]
    result = _build_result(
        plan["run_id"], plan["started_at"], policies, acc, events,
        cfg["n_users"], cfg["n_rounds"], cfg["tasks_per_round"],
        use_llm=False, seed=cfg["seed"],
    )
    result["judge_mode"] = "claude-code"
    Path(out_path).write_text(json.dumps(result, indent=2))
    return result


# ── Shared result builder ───────────────────────────────────────────────────

def _build_result(
    run_id: str, started_at: str, policies: list[str],
    acc: dict, events: list[dict],
    n_users: int, n_rounds: int, tasks_per_round: int,
    use_llm: bool, seed: int,
) -> dict:
    summary = {
        p: {
            "total_reward": acc[p]["total_reward"],
            "mean_reward": (
                acc[p]["total_reward"] / acc[p]["n_pulls"]
                if acc[p]["n_pulls"] > 0 else 0.0
            ),
            "n_pulls": acc[p]["n_pulls"],
            "cumulative_rewards": acc[p]["cumulative_rewards"],
            "action_counts": acc[p]["action_counts"],
        }
        for p in policies
    }
    winner = max(policies, key=lambda p: summary[p]["total_reward"])

    persona_breakdown: dict[str, dict] = {}
    for ev in events:
        pname = ev["persona"]
        pol = ev["policy"]
        persona_breakdown.setdefault(pname, {}).setdefault(pol, {"reward": 0.0, "n": 0})
        persona_breakdown[pname][pol]["reward"] += ev["reward"]
        persona_breakdown[pname][pol]["n"] += 1

    return {
        "run_id": run_id,
        "started_at": started_at,
        "finished_at": time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()),
        "config": {
            "n_users": n_users, "n_rounds": n_rounds,
            "tasks_per_round": tasks_per_round, "policies": policies,
            "use_llm": use_llm, "seed": seed,
        },
        "summary": summary,
        "winner": winner,
        "persona_breakdown": persona_breakdown,
        "events": events,
    }


# ── CLI ─────────────────────────────────────────────────────────────────────

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="oO simulation runner")
    parser.add_argument("--judge", choices=["rule", "llm", "claude-code"], default="rule")
    parser.add_argument("--phase", choices=["score", "reward"], default=None,
                        help="For --judge claude-code only")
    parser.add_argument("--plan", default=None,
                        help="Plan file path (for --judge claude-code --phase reward)")
    parser.add_argument("--n-users", type=int, default=5)
    parser.add_argument("--n-rounds", type=int, default=20)
    parser.add_argument("--tasks-per-round", type=int, default=8)
    parser.add_argument("--ml-url", default="http://localhost:5001")
    parser.add_argument("--policies", nargs="+", default=["linucb-v1", "egreedy-v1"])
    parser.add_argument("--no-llm", action="store_true",
                        help="Alias for --judge rule (backwards compat)")
    parser.add_argument("--seed", type=int, default=42)
    parser.add_argument("--out", default=None)
    args = parser.parse_args()

    if args.no_llm:
        args.judge = "rule"

    out_path = args.out or f"/tmp/oo-sim-{int(time.time())}.json"

    if args.judge == "claude-code":
        if args.phase == "score":
            run_score_phase(
                n_users=args.n_users, n_rounds=args.n_rounds,
                tasks_per_round=args.tasks_per_round, ml_url=args.ml_url,
                policies=args.policies, seed=args.seed, out_path=out_path,
            )
        elif args.phase == "reward":
            if not args.plan:
                print("ERROR: --plan is required for --phase reward", file=sys.stderr)
                sys.exit(1)
            result = run_reward_phase(args.plan, out_path, args.ml_url)
            print()
            print(f"Winner : {result['winner']}")
            for p, s in result["summary"].items():
                print(f"  {p:20s}  total={s['total_reward']:+.2f}  mean={s['mean_reward']:+.4f}  pulls={s['n_pulls']}")
            print(f"Results: {out_path}")
        else:
            print("ERROR: --judge claude-code requires --phase score or --phase reward",
                  file=sys.stderr)
            sys.exit(1)
    else:
        use_llm = (args.judge == "llm")
        print(f"oO simulation: {args.n_users} users × {args.n_rounds} rounds")
        print(f"Policies : {args.policies}")
        print(f"ML URL   : {args.ml_url}")
        print(f"Judge    : {args.judge}")
        print()

        result = run_simulation(
            n_users=args.n_users, n_rounds=args.n_rounds,
            tasks_per_round=args.tasks_per_round, ml_url=args.ml_url,
            policies=args.policies, use_llm=use_llm, seed=args.seed,
        )
        Path(out_path).write_text(json.dumps(result, indent=2))
        print()
        print(f"Winner : {result['winner']}")
        for p, s in result["summary"].items():
            print(f"  {p:20s}  total={s['total_reward']:+.2f}  mean={s['mean_reward']:+.4f}  pulls={s['n_pulls']}")
        print(f"Results: {out_path}")