class CalculatorSkill(Skill):
   def _define_metadata(self):
       return SkillMetadata(
           name="calculator",
           description="Evaluate mathematical expressions. Supports arithmetic, powers, and "
                       "math functions: sqrt, abs, round, log, sin, cos, tan.",
           category=SkillCategory.REASONING,
           tags=["math", "arithmetic", "compute"],
           output_type="text", cost_estimate=0.0,
       )


   def _define_schema(self):
       return {"type": "object",
               "properties": {"expression": {"type": "string",
                   "description": "A Python math expression e.g. '2**10 + sqrt(144)'"}},
               "required": ["expression"]}


   def execute(self, expression: str) -> str:
       import math
       safe = {"__builtins__": {}, "sqrt": math.sqrt, "abs": abs, "round": round,
               "pow": pow, "log": math.log, "pi": math.pi, "e": math.e,
               "sin": math.sin, "cos": math.cos, "tan": math.tan}
       try:
           return f"Result: {eval(expression, safe)}"
       except Exception as ex:
           return f"Error: {ex}"


class TextSummarizerSkill(Skill):
   def _define_metadata(self):
       return SkillMetadata(
           name="text_summarizer",
           description="Summarize text at three verbosity levels: brief (1-2 sentences), "
                       "standard (1 paragraph), or detailed (structured bullets).",
           category=SkillCategory.GENERATION,
           tags=["summarize", "nlp", "text", "writing"],
       )


   def _define_schema(self):
       return {"type": "object",
               "properties": {
                   "text": {"type": "string"},
                   "mode": {"type": "string", "enum": ["brief", "standard", "detailed"],
                            "default": "standard"}},
               "required": ["text"]}


   def execute(self, text: str, mode: str = "standard") -> str:
       instructions = {"brief": "in 1-2 sentences", "standard": "in one paragraph",
                       "detailed": "as structured bullet points covering main ideas, key details, and conclusions"}
       r = client.chat.completions.create(
           model=MODEL, max_tokens=300,
           messages=[
               {"role": "system",  "content": f"Summarize {instructions.get(mode, instructions['standard'])}. Be concise."},
               {"role": "user",    "content": text}])
       return r.choices[0].message.content


class DataAnalystSkill(Skill):
   def _define_metadata(self):
       return SkillMetadata(
           name="data_analyst",
           description="Analyse structured data (JSON or CSV) and extract statistical insights, "
                       "trends, or answer specific questions.",
           category=SkillCategory.DATA,
           tags=["data", "analysis", "statistics", "csv", "json"],
       )


   def _define_schema(self):
       return {"type": "object",
               "properties": {
                   "data":     {"type": "string", "description": "Data as JSON array or CSV"},
                   "question": {"type": "string", "description": "Analytical question to answer"}},
               "required": ["data", "question"]}


   def execute(self, data: str, question: str) -> str:
       r = client.chat.completions.create(
           model=MODEL, max_tokens=400,
           messages=[
               {"role": "user",   "content": f"Data:\n{data}\n\nQuestion: {question}"}])
       return r.choices[0].message.content


class CodeGeneratorSkill(Skill):
   def _define_metadata(self):
       return SkillMetadata(
           name="code_generator",
           description="Generate clean, commented Python code for a given task with a brief explanation.",
           category=SkillCategory.GENERATION,
           tags=["code", "python", "programming", "script"],
       )


   def _define_schema(self):
       return {"type": "object",
               "properties": {
                   "task":     {"type": "string"},
                   "language": {"type": "string", "default": "python"}},
               "required": ["task"]}


   def execute(self, task: str, language: str = "python") -> str:
       r = client.chat.completions.create(
           model=MODEL, max_tokens=500,
           messages=[
               {"role": "system", "content": f"Expert {language} developer. Write clean, commented code with a one-line explanation."},
               {"role": "user",   "content": task}])
       return r.choices[0].message.content