//! Skill runners for different execution modes

use async_trait::async_trait;
use serde_json::Value;
use std::process::Command;
use std::time::Instant;
use tracing::warn;
use zclaw_types::Result;

use super::{Skill, SkillContext, SkillManifest, SkillResult};

/// Prompt-only skill execution
pub struct PromptOnlySkill {
    manifest: SkillManifest,
    prompt_template: String,
}

impl PromptOnlySkill {
    pub fn new(manifest: SkillManifest, prompt_template: String) -> Self {
        Self { manifest, prompt_template }
    }

    fn format_prompt(&self, input: &Value) -> String {
        let mut prompt = self.prompt_template.clone();

        if let Value::String(s) = input {
            prompt = prompt.replace("{{input}}", s);
        } else {
            prompt = prompt.replace("{{input}}", &serde_json::to_string_pretty(input).unwrap_or_default());
        }

        prompt
    }
}

#[async_trait]
impl Skill for PromptOnlySkill {
    fn manifest(&self) -> &SkillManifest {
        &self.manifest
    }

    async fn execute(&self, context: &SkillContext, input: Value) -> Result<SkillResult> {
        let prompt = self.format_prompt(&input);

        // If an LLM completer is available, generate an AI response
        if let Some(completer) = &context.llm {
            match completer.complete(&prompt).await {
                Ok(response) => return Ok(SkillResult::success(Value::String(response))),
                Err(e) => {
                    warn!("[PromptOnlySkill] LLM completion failed: {}, falling back to raw prompt", e);
                    // Fall through to return raw prompt
                }
            }
        }

        // No LLM available — return formatted prompt (backward compatible)
        Ok(SkillResult::success(Value::String(prompt)))
    }
}

/// Python script skill execution
pub struct PythonSkill {
    manifest: SkillManifest,
    script_path: std::path::PathBuf,
}

impl PythonSkill {
    pub fn new(manifest: SkillManifest, script_path: std::path::PathBuf) -> Self {
        Self { manifest, script_path }
    }
}

#[async_trait]
impl Skill for PythonSkill {
    fn manifest(&self) -> &SkillManifest {
        &self.manifest
    }

    async fn execute(&self, context: &SkillContext, input: Value) -> Result<SkillResult> {
        let start = Instant::now();
        let input_json = serde_json::to_string(&input).unwrap_or_default();

        let output = Command::new("python3")
            .arg(&self.script_path)
            .env("SKILL_INPUT", &input_json)
            .env("AGENT_ID", &context.agent_id)
            .env("SESSION_ID", &context.session_id)
            .output()
            .map_err(|e| zclaw_types::ZclawError::ToolError(format!("Failed to execute Python: {}", e)))?;

        let duration_ms = start.elapsed().as_millis() as u64;

        if output.status.success() {
            let stdout = String::from_utf8_lossy(&output.stdout);
            let result = serde_json::from_str(&stdout)
                .map(|v| SkillResult {
                    success: true,
                    output: v,
                    error: None,
                    duration_ms: Some(duration_ms),
                    tokens_used: None,
                })
                .unwrap_or_else(|_| SkillResult::success(Value::String(stdout.to_string())));
            Ok(result)
        } else {
            let stderr = String::from_utf8_lossy(&output.stderr);
            Ok(SkillResult::error(stderr))
        }
    }
}

/// Shell command skill execution
pub struct ShellSkill {
    manifest: SkillManifest,
    command: String,
}

impl ShellSkill {
    pub fn new(manifest: SkillManifest, command: String) -> Self {
        Self { manifest, command }
    }
}

#[async_trait]
impl Skill for ShellSkill {
    fn manifest(&self) -> &SkillManifest {
        &self.manifest
    }

    async fn execute(&self, context: &SkillContext, input: Value) -> Result<SkillResult> {
        let start = Instant::now();

        let mut cmd = self.command.clone();
        if let Value::String(s) = input {
            // Shell-quote the input to prevent command injection
            let quoted = shlex::try_quote(&s)
                .map_err(|_| zclaw_types::ZclawError::ToolError(
                    "Input contains null bytes and cannot be safely quoted".to_string()
                ))?;
            cmd = cmd.replace("{{input}}", &quoted);
        }

        #[cfg(target_os = "windows")]
        let output = {
            Command::new("cmd")
                .args(["/C", &cmd])
                .current_dir(context.working_dir.as_ref().unwrap_or(&std::path::PathBuf::from(".")))
                .output()
                .map_err(|e| zclaw_types::ZclawError::ToolError(format!("Failed to execute shell: {}", e)))?
        };

        #[cfg(not(target_os = "windows"))]
        let output = {
            Command::new("sh")
                .args(["-c", &cmd])
                .current_dir(context.working_dir.as_ref().unwrap_or(&std::path::PathBuf::from(".")))
                .output()
                .map_err(|e| zclaw_types::ZclawError::ToolError(format!("Failed to execute shell: {}", e)))?
        };

        let _duration_ms = start.elapsed().as_millis() as u64;

        if output.status.success() {
            let stdout = String::from_utf8_lossy(&output.stdout);
            Ok(SkillResult::success(Value::String(stdout.to_string())))
        } else {
            let stderr = String::from_utf8_lossy(&output.stderr);
            Ok(SkillResult::error(stderr))
        }
    }
}