import json
import hashlib
from flask import Blueprint, request, jsonify
from datasets import load_dataset

bp = Blueprint("harbor_datasets", __name__, url_prefix="/api/harbor/datasets")

_cache: dict[str, dict] = {}


def _make_id(repo: str, split: str) -> str:
    key = f"{repo}:{split}"
    return hashlib.md5(key.encode()).hexdigest()[:12]


def _parse_trajectory(traj_json: str) -> dict:
    """Parse ATIF trajectory JSON into structured steps (v1.2 and v1.5)."""
    if not traj_json:
        return {"steps": [], "agent_info": {}, "final_metrics": {}}

    try:
        traj = json.loads(traj_json) if isinstance(traj_json, str) else traj_json
    except (json.JSONDecodeError, TypeError):
        return {"steps": [], "agent_info": {}, "final_metrics": {}}

    steps = []
    for step in traj.get("steps", []):
        parsed = {
            "index": len(steps),
            "source": step.get("source", "unknown"),
            "message": step.get("message", ""),
            "timestamp": step.get("timestamp"),
        }
        if step.get("source") == "agent":
            parsed["reasoning"] = step.get("reasoning_content", "")
            parsed["tool_calls"] = []
            for tc in step.get("tool_calls", []):
                args = tc.get("arguments", {})
                tool_call = {
                    "function": tc.get("function_name", ""),
                    "arguments": args,
                }
                # v1.2 uses "command", v1.5 uses "cmd"
                cmd = args.get("command", "") or args.get("cmd", "")
                if cmd:
                    tool_call["command"] = cmd
                parsed["tool_calls"].append(tool_call)

            obs = step.get("observation", {})
            if obs:
                if isinstance(obs, dict) and "results" in obs:
                    results = obs["results"]
                    if results:
                        parsed["observation"] = results[0].get("content", "") if isinstance(results[0], dict) else str(results[0])
                    else:
                        parsed["observation"] = ""
                elif isinstance(obs, str):
                    parsed["observation"] = obs
                else:
                    parsed["observation"] = json.dumps(obs)

            parsed["metrics"] = step.get("metrics", {})
        elif step.get("source") == "system":
            pass  # message is enough
        elif step.get("source") == "user":
            pass  # message is enough

        steps.append(parsed)

    return {
        "steps": steps,
        "agent_info": traj.get("agent", {}),
        "final_metrics": traj.get("final_metrics", {}),
    }


def _parse_trajectory_raw(traj_raw: str) -> list[dict]:
    """Parse trajectory_raw into chat-style steps.

    Handles two formats:
    1. Flat list of OpenAI messages
    2. Dict with {info, messages, trajectory_format} (mini-swe-agent format)
    """
    if not traj_raw:
        return []

    try:
        parsed = json.loads(traj_raw) if isinstance(traj_raw, str) else traj_raw
    except (json.JSONDecodeError, TypeError):
        return []

    # Extract messages list and optional info
    info = {}
    if isinstance(parsed, dict):
        info = parsed.get("info", {})
        messages = parsed.get("messages", [])
    elif isinstance(parsed, list):
        messages = parsed
    else:
        return []

    steps = []
    for i, msg in enumerate(messages):
        if not isinstance(msg, dict):
            continue

        role = msg.get("role", "unknown")
        content = msg.get("content", "")

        step = {
            "index": i,
            "role": role,
            "content": content if isinstance(content, str) else json.dumps(content) if content else "",
        }

        # Assistant messages may have tool_calls (OpenAI format)
        if role == "assistant" and "tool_calls" in msg:
            tool_calls = msg["tool_calls"]
            step["tool_calls"] = []
            for tc in (tool_calls if isinstance(tool_calls, list) else []):
                fn = tc.get("function", {})
                call = {
                    "id": tc.get("id", ""),
                    "function": fn.get("name", ""),
                    "arguments_raw": fn.get("arguments", ""),
                }
                try:
                    args = json.loads(fn.get("arguments", "{}"))
                    call["arguments"] = args
                    if "command" in args:
                        call["command"] = args["command"]
                except (json.JSONDecodeError, TypeError):
                    call["arguments"] = {}
                step["tool_calls"].append(call)

        # Tool messages have tool_call_id
        if role == "tool":
            step["tool_call_id"] = msg.get("tool_call_id", "")

        steps.append(step)

    # Attach info as metadata on first step if available
    if steps and info:
        steps[0]["_info"] = info

    return steps


def _parse_agent_output_jsonl(agent_output: str) -> list[dict]:
    """Parse Codex-style JSONL agent_output into chat-style steps.

    Codex emits newline-delimited JSON with item.completed events containing
    reasoning, agent_message, and command_execution items.  Falls back
    gracefully if the format is unrecognised.
    """
    if not agent_output:
        return []

    steps: list[dict] = []
    idx = 0

    for line in agent_output.strip().split("\n"):
        try:
            event = json.loads(line)
        except (json.JSONDecodeError, TypeError):
            continue

        if event.get("type") != "item.completed":
            continue

        item = event.get("item", {})
        item_type = item.get("type", "")

        if item_type == "reasoning":
            steps.append({
                "index": idx,
                "role": "assistant",
                "content": item.get("text", ""),
                "_reasoning": True,
            })
            idx += 1

        elif item_type == "agent_message":
            steps.append({
                "index": idx,
                "role": "assistant",
                "content": item.get("text", ""),
            })
            idx += 1

        elif item_type == "command_execution":
            cmd = item.get("command", "")
            call_id = item.get("call_id", item.get("id", ""))
            # Assistant step with tool call
            steps.append({
                "index": idx,
                "role": "assistant",
                "content": "",
                "tool_calls": [{
                    "id": call_id,
                    "function": "exec_command",
                    "arguments_raw": json.dumps({"command": cmd}),
                    "arguments": {"command": cmd},
                    "command": cmd,
                }],
            })
            idx += 1
            # Tool response step — Codex uses "aggregated_output", others use "output"
            output = item.get("output", "") or item.get("aggregated_output", "")
            exit_code = item.get("exit_code")
            status = item.get("status", "")
            response_text = output
            if exit_code is not None:
                header = f"[exit code: {exit_code}]"
                if status:
                    header = f"[{status} — exit code: {exit_code}]"
                response_text = f"{header}\n{output}" if output else header
            steps.append({
                "index": idx,
                "role": "tool",
                "content": response_text,
                "tool_call_id": call_id,
            })
            idx += 1

    return steps


def _build_instance_summary(row: dict) -> dict:
    """Build a summary for one instance row."""
    return {
        "instance_id": row.get("instance_id", ""),
        "resolved": row.get("resolved", False),
        "reward": row.get("reward", 0),
        "model": row.get("model", ""),
        "agent": row.get("agent", ""),
        "duration_seconds": row.get("duration_seconds", 0),
        "error": row.get("error", ""),
    }


@bp.route("/load", methods=["POST"])
def load_dataset_endpoint():
    data = request.get_json()
    repo = data.get("repo", "").strip()
    if not repo:
        return jsonify({"error": "repo is required"}), 400

    split = data.get("split", "train")

    try:
        ds = load_dataset(repo, split=split)
    except Exception as e:
        return jsonify({"error": f"Failed to load dataset: {e}"}), 400

    ds_id = _make_id(repo, split)

    # Build instance summaries and index
    instances = []
    instance_index = {}
    for i in range(len(ds)):
        row = ds[i]
        summary = _build_instance_summary(row)
        instances.append(summary)
        instance_index[row.get("instance_id", "")] = i

    _cache[ds_id] = {
        "repo": repo,
        "split": split,
        "dataset": ds,
        "instances": instances,
        "instance_index": instance_index,
    }

    short_name = repo.rsplit("/", 1)[-1] if "/" in repo else repo

    return jsonify({
        "id": ds_id,
        "repo": repo,
        "name": short_name,
        "split": split,
        "instances": instances,
        "n_instances": len(instances),
    })


@bp.route("/", methods=["GET"])
def list_datasets():
    result = []
    for ds_id, info in _cache.items():
        result.append({
            "id": ds_id,
            "repo": info["repo"],
            "name": info["repo"].rsplit("/", 1)[-1] if "/" in info["repo"] else info["repo"],
            "split": info["split"],
            "n_instances": len(info["instances"]),
            "instances": info["instances"],
        })
    return jsonify(result)


@bp.route("/<ds_id>/instances", methods=["GET"])
def get_instances(ds_id):
    if ds_id not in _cache:
        return jsonify({"error": "Dataset not loaded"}), 404
    return jsonify(_cache[ds_id]["instances"])


@bp.route("/<ds_id>/instance/<path:instance_id>", methods=["GET"])
def get_instance(ds_id, instance_id):
    """Get full parsed trajectory for one instance."""
    if ds_id not in _cache:
        return jsonify({"error": "Dataset not loaded"}), 404

    info = _cache[ds_id]
    if instance_id not in info["instance_index"]:
        return jsonify({"error": f"Instance {instance_id} not found"}), 404

    idx = info["instance_index"][instance_id]
    row = info["dataset"][idx]

    # Parse ATIF trajectory
    atif = _parse_trajectory(row.get("trajectory", ""))

    # Parse raw trajectory (OpenAI messages), fall back to agent_output JSONL
    raw_steps = _parse_trajectory_raw(row.get("trajectory_raw", ""))
    if not raw_steps and row.get("agent_output"):
        raw_steps = _parse_agent_output_jsonl(row["agent_output"])

    return jsonify({
        "instance_id": instance_id,
        "resolved": row.get("resolved", False),
        "reward": row.get("reward", 0),
        "model": row.get("model", ""),
        "agent": row.get("agent", ""),
        "duration_seconds": row.get("duration_seconds", 0),
        "error": row.get("error", ""),
        "atif": atif,
        "raw_steps": raw_steps,
        "n_atif_steps": len(atif["steps"]),
        "n_raw_steps": len(raw_steps),
    })


@bp.route("/<ds_id>/instance/<path:instance_id>/raw", methods=["GET"])
def get_instance_raw(ds_id, instance_id):
    """Get raw logs: agent_stdout, setup_stderr, verifier_report."""
    if ds_id not in _cache:
        return jsonify({"error": "Dataset not loaded"}), 404

    info = _cache[ds_id]
    if instance_id not in info["instance_index"]:
        return jsonify({"error": f"Instance {instance_id} not found"}), 404

    idx = info["instance_index"][instance_id]
    row = info["dataset"][idx]

    return jsonify({
        "instance_id": instance_id,
        "agent_stdout": row.get("agent_stdout", ""),
        "setup_stderr": row.get("setup_stderr", ""),
        "verifier_report": row.get("verifier_report", ""),
        "verifier_stdout": row.get("verifier_stdout", ""),
    })


@bp.route("/<ds_id>", methods=["DELETE"])
def unload_dataset(ds_id):
    if ds_id in _cache:
        del _cache[ds_id]
    return jsonify({"status": "ok"})