"""Skill discovery, parsing, and execution."""

import os
import re
import json
import subprocess
import time


def log(msg):
    """Import-safe logging — overridden by agent.py at init."""
    print(f"[skills] {msg}", flush=True)


def set_logger(fn):
    """Allow agent.py to inject its logger."""
    global log
    log = fn


LARGE_OUTPUT_THRESHOLD = 2000
_output_counter = 0


def parse_skill_md(path):
    """Parse a SKILL.md frontmatter into a tool definition.
    Returns tool definition dict or None on failure."""
    try:
        with open(path) as f:
            content = f.read()
    except Exception as e:
        log(f"Cannot read {path}: {e}")
        return None

    content = content.replace("\r\n", "\n")

    match = re.match(r"^---\n(.*?)\n---", content, re.DOTALL)
    if not match:
        log(f"No frontmatter in {path}")
        return None

    fm = {}
    current_key = None
    current_param = None
    params = {}

    for line in match.group(1).split("\n"):
        stripped = line.strip()
        if not stripped or stripped.startswith("#"):
            continue

        indent = len(line) - len(line.lstrip())

        if indent >= 2 and current_key == "parameters":
            if indent >= 4 and current_param:
                k, _, v = stripped.partition(":")
                k = k.strip()
                v = v.strip().strip('"').strip("'")
                if k == "required":
                    v = v.lower() in ("true", "yes", "1")
                params[current_param][k] = v
            elif ":" in stripped:
                param_name = stripped.rstrip(":").strip()
                current_param = param_name
                params[param_name] = {}
        elif ":" in line and indent == 0:
            k, _, v = line.partition(":")
            k = k.strip()
            v = v.strip().strip('"').strip("'")
            fm[k] = v
            current_key = k
            if k == "parameters":
                current_param = None

    if "name" not in fm:
        log(f"No 'name' field in {path}")
        return None

    if "description" not in fm:
        log(f"Warning: no 'description' in {path}")

    properties = {}
    required = []
    for pname, pdata in params.items():
        ptype = pdata.get("type", "string")
        if ptype not in ("string", "integer", "number", "boolean", "array", "object"):
            log(f"Warning: unknown type '{ptype}' for param '{pname}' in {path}")
        properties[pname] = {
            "type": ptype,
            "description": pdata.get("description", ""),
        }
        if pdata.get("required", False):
            required.append(pname)

    return {
        "type": "function",
        "function": {
            "name": fm["name"],
            "description": fm.get("description", ""),
            "parameters": {
                "type": "object",
                "properties": properties,
                "required": required,
            },
        },
    }


def discover_skills(skill_dirs):
    """Scan skill directories and return tool definitions + script paths."""
    tools = []
    scripts = {}

    for skill_dir in skill_dirs:
        if not os.path.isdir(skill_dir):
            continue
        for name in sorted(os.listdir(skill_dir)):
            skill_path = os.path.join(skill_dir, name)
            skill_md = os.path.join(skill_path, "SKILL.md")
            if not os.path.isfile(skill_md):
                continue

            tool_def = parse_skill_md(skill_md)
            if not tool_def:
                continue

            for ext in ("run.py", "run.sh"):
                script = os.path.join(skill_path, ext)
                if os.path.isfile(script):
                    scripts[tool_def["function"]["name"]] = script
                    break

            if tool_def["function"]["name"] in scripts:
                tools.append(tool_def)

    return tools, scripts


def execute_skill(script_path, args, workspace, config):
    """Execute a skill script with args as JSON on stdin.
    Large outputs are saved to a file with a preview returned."""
    global _output_counter
    env = os.environ.copy()
    env["WORKSPACE"] = workspace
    env["SEARX_URL"] = config.get("searx_url", "https://searx.mymx.me")

    try:
        result = subprocess.run(
            ["python3" if script_path.endswith(".py") else "bash", script_path],
            input=json.dumps(args),
            capture_output=True,
            text=True,
            timeout=120,
            env=env,
        )
        output = result.stdout
        if result.stderr:
            output += f"\n[stderr] {result.stderr}"
        output = output.strip() or "[no output]"

        if len(output) > LARGE_OUTPUT_THRESHOLD:
            output_dir = f"{workspace}/tool_outputs"
            os.makedirs(output_dir, exist_ok=True)
            _output_counter += 1
            filepath = f"{output_dir}/output_{_output_counter}.txt"
            with open(filepath, "w") as f:
                f.write(output)
            preview = output[:1500]
            return f"{preview}\n\n[output truncated — full result ({len(output)} chars) saved to {filepath}. Use read_file to view it.]"

        return output
    except subprocess.TimeoutExpired:
        return "[skill timed out after 120s]"
    except Exception as e:
        return f"[skill error: {e}]"