"""Harness² 融合演示：不花模型钱，跑通一轮完整改进。

用法（在项目根目录）：
    python3 examples/harness2_demo.py --mode parallel --k 1
    python3 examples/harness2_demo.py --mode sequential --k 1 --output /tmp/h2demo

任务是对账本求和。base harness 的脚本只加正数（账本含一笔负数 credit，
base 会漏掉它）；确定性编辑器去掉正数过滤；选择器按产物挑带符号和；
反思器把“正负都要算”写进经验库。跑完打印：被采纳的产物、回落情况、
经验库条目位置。真实接线时，这里的三个确定性类换成 codex 任务
（见 docs/harness2.md），执行器换成 Worker 的任务执行，循环本身不变。
"""

import argparse
import subprocess
import sys
import tempfile
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))

from cloud.harness2 import (  # noqa: E402
    EditResult, Library, Rollout, improve_task, read_tree, write_tree,
)

BASE_SCRIPT = """import csv
import sys
from decimal import Decimal
with open(sys.argv[1]) as f:
    amounts = [Decimal(r['amount']) for r in csv.DictReader(f)]
print(f"Total: {sum((a for a in amounts if a > 0), Decimal(0)):.2f}")
"""

BASE_TREE = {
    "AGENTS.md": "Use scripts/summarize.py to total the ledger.\n",
    "scripts/summarize.py": BASE_SCRIPT,
}


class LedgerAdapter:
    task_id = "ledger-1"
    domain = "accounting"
    prompt = "Sum every signed amount in ledger.csv. Return Total: with two decimals."

    def __init__(self, root):
        self.root = Path(root)
        self.root.mkdir(parents=True, exist_ok=True)
        self.ledger = self.root / "ledger.csv"
        self.ledger.write_text("amount\n100.25\n-20.10\n5.00\n", encoding="utf-8")
        self.executions = 0

    def base_harness(self):
        return dict(BASE_TREE)

    def execute(self, label, harness):
        self.executions += 1
        work = self.root / "runs" / label
        work.mkdir(parents=True, exist_ok=True)
        write_tree(harness, work / "harness")
        proc = subprocess.run(
            [sys.executable, str(work / "harness" / "scripts" / "summarize.py"),
             str(self.ledger)], capture_output=True, text=True, timeout=10)
        out = proc.stdout.strip()
        return Rollout(label=label, ok=proc.returncode == 0,
                       delivered=out.startswith("Total:"), deliverable_text=out,
                       trajectory="[ACTION] Run scripts/summarize.py\n[OBSERVATION]\n" + out,
                       cost_usd=0.01)

    def validate_tree(self, harness):
        if "scripts/summarize.py" not in harness:
            raise ValueError("The local executor requires scripts/summarize.py")


class FixEditor:
    def edit(self, mission, context_dir, label):
        harness_dir = Path(context_dir) / "harness"
        script = harness_dir / "scripts" / "summarize.py"
        script.write_text(script.read_text().replace(" if a > 0", ""), encoding="utf-8")
        return EditResult(tree=read_tree(harness_dir),
                          notes="Keep signed amounts: the base total omitted credits.")


class PickSignedSelector:
    def select(self, mission, context_dir):
        for path in sorted((Path(context_dir) / "candidates").glob("*.md")):
            if "Total: 85.15" in path.read_text():
                return path.stem, "The signed total matches the source ledger.", 0.0
        raise ValueError("no candidate with the signed total")


class LedgerReflector:
    def reflect(self, mission, context_dir):
        root = Path(context_dir)
        changed = (root / "harness" / "scripts" / "summarize.py").read_text() != (
            root / "base_harness" / "scripts" / "summarize.py").read_text()
        if not changed:
            return {}
        return {
            "cue": "When a ledger includes credits and debits",
            "lesson": "Include both signs when summing in scripts/summarize.py.",
            "evidence": "Removing the positive-only filter changed the probe total to "
                        "include the credits omitted by the base trajectory.",
            "confidence": "high for this observed arithmetic contrast",
        }


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--mode", default="parallel", choices=["parallel", "sequential"])
    ap.add_argument("--k", type=int, default=1)
    ap.add_argument("--output", default="")
    args = ap.parse_args()
    tmp = None
    root = Path(args.output) if args.output else Path(tempfile.mkdtemp(prefix="h2demo-"))
    if not args.output:
        tmp = root
    adapter = LedgerAdapter(root)
    library = Library(root / "library", "accounting")
    result = improve_task(adapter, FixEditor(), selector=PickSignedSelector(),
                          reflector=LedgerReflector(), work_dir=root / "work",
                          k=args.k, mode=args.mode, library=library)
    chosen = result.mode_result.rollouts[result.selection.chosen_label]
    print(f"mode={result.mode} k={args.k} ok={result.ok}")
    print(f"executions={adapter.executions} (base + candidates + finals)")
    print(f"chosen={result.selection.chosen_label} deliverable={chosen.deliverable_text}")
    print(f"fell_back={result.mode_result.fell_back or 'none'}")
    print(f"library_entry={result.library_entry}")
    print(f"experience={result.experience.get('lesson', '(none)')}")
    print(f"work_dir={root}")
    assert chosen.deliverable_text == "Total: 85.15", "demo must end at the signed total"
    assert result.library_entry is not None, "demo must enter the library"
    print("demo OK: signed total adopted and stored in the library")
    _ = tmp


if __name__ == "__main__":
    main()