//! Adapter types bridging runtime interfaces

use std::pin::Pin;
use std::sync::Arc;
use async_trait::async_trait;
use serde_json::{json, Value};

use zclaw_runtime::{LlmDriver, tool::{SkillExecutor, HandExecutor}};
use zclaw_skills::{SkillRegistry, LlmCompleter, SkillCompletion, SkillToolCall};
use zclaw_hands::HandRegistry;
use zclaw_types::{AgentId, Result, ToolDefinition};

/// Adapter that bridges `zclaw_runtime::LlmDriver` -> `zclaw_skills::LlmCompleter`
pub(crate) struct LlmDriverAdapter {
    pub(crate) driver: Arc<dyn LlmDriver>,
    pub(crate) max_tokens: u32,
    pub(crate) temperature: f32,
}

impl LlmCompleter for LlmDriverAdapter {
    fn complete(
        &self,
        prompt: &str,
    ) -> Pin<Box<dyn std::future::Future<Output = std::result::Result<String, String>> + Send + '_>> {
        let driver = self.driver.clone();
        let prompt = prompt.to_string();
        Box::pin(async move {
            let request = zclaw_runtime::CompletionRequest {
                messages: vec![zclaw_types::Message::user(prompt)],
                max_tokens: Some(self.max_tokens),
                temperature: Some(self.temperature),
                ..Default::default()
            };
            let response = driver.complete(request).await
                .map_err(|e| format!("LLM completion error: {}", e))?;
            // Extract text from content blocks
            let text: String = response.content.iter()
                .filter_map(|block| match block {
                    zclaw_runtime::ContentBlock::Text { text } => Some(text.as_str()),
                    _ => None,
                })
                .collect::<Vec<_>>()
                .join("");
            Ok(text)
        })
    }

    fn complete_with_tools(
        &self,
        prompt: &str,
        system_prompt: Option<&str>,
        tools: Vec<ToolDefinition>,
    ) -> Pin<Box<dyn std::future::Future<Output = std::result::Result<SkillCompletion, String>> + Send + '_>> {
        let driver = self.driver.clone();
        let prompt = prompt.to_string();
        let system = system_prompt.map(|s| s.to_string());
        let max_tokens = self.max_tokens;
        let temperature = self.temperature;
        Box::pin(async move {
            let mut messages = Vec::new();
            messages.push(zclaw_types::Message::user(prompt));

            let request = zclaw_runtime::CompletionRequest {
                model: String::new(),
                system,
                messages,
                tools,
                max_tokens: Some(max_tokens),
                temperature: Some(temperature),
                stop: Vec::new(),
                stream: false,
                thinking_enabled: false,
                reasoning_effort: None,
                plan_mode: false,
            };
            let response = driver.complete(request).await
                .map_err(|e| format!("LLM completion error: {}", e))?;

            let mut text_parts = Vec::new();
            let mut tool_calls = Vec::new();
            for block in &response.content {
                match block {
                    zclaw_runtime::ContentBlock::Text { text } => {
                        text_parts.push(text.clone());
                    }
                    zclaw_runtime::ContentBlock::ToolUse { id, name, input } => {
                        tool_calls.push(SkillToolCall {
                            id: id.clone(),
                            name: name.clone(),
                            input: input.clone(),
                        });
                    }
                    _ => {}
                }
            }

            Ok(SkillCompletion {
                text: text_parts.join(""),
                tool_calls,
            })
        })
    }
}

/// Skill executor implementation for Kernel
pub struct KernelSkillExecutor {
    pub(crate) skills: Arc<SkillRegistry>,
    pub(crate) llm: Arc<dyn LlmCompleter>,
    /// Shared tool registry, updated before each skill execution from the
    /// agent loop's freshly-built registry. Uses std::sync because reads
    /// happen from async code but writes are brief and infrequent.
    pub(crate) tool_registry: std::sync::RwLock<Option<zclaw_runtime::ToolRegistry>>,
}

impl KernelSkillExecutor {
    pub fn new(skills: Arc<SkillRegistry>, driver: Arc<dyn LlmDriver>) -> Self {
        let llm: Arc<dyn LlmCompleter> = Arc::new(LlmDriverAdapter { driver, max_tokens: 4096, temperature: 0.7 });
        Self { skills, llm, tool_registry: std::sync::RwLock::new(None) }
    }

    /// Update the tool registry snapshot. Called by the kernel before each
    /// agent loop iteration so skill execution sees the latest tool set.
    pub fn set_tool_registry(&self, registry: zclaw_runtime::ToolRegistry) {
        if let Ok(mut guard) = self.tool_registry.write() {
            *guard = Some(registry);
        }
    }

    /// Resolve the tool definitions declared by a skill manifest against
    /// the currently active tool registry.
    fn resolve_tool_definitions(&self, skill_id: &str) -> Vec<ToolDefinition> {
        let manifests = self.skills.manifests_snapshot();
        let manifest = match manifests.get(&zclaw_types::SkillId::new(skill_id)) {
            Some(m) => m,
            None => return vec![],
        };
        if manifest.tools.is_empty() {
            return vec![];
        }
        let guard = match self.tool_registry.read() {
            Ok(g) => g,
            Err(_) => return vec![],
        };
        let registry = match guard.as_ref() {
            Some(r) => r,
            None => return vec![],
        };
        // Only include definitions for tools declared in the skill manifest.
        registry.definitions().into_iter()
            .filter(|def| manifest.tools.iter().any(|t| t == &def.name))
            .collect()
    }
}

#[async_trait]
impl SkillExecutor for KernelSkillExecutor {
    async fn execute_skill(
        &self,
        skill_id: &str,
        agent_id: &str,
        session_id: &str,
        input: Value,
    ) -> Result<Value> {
        let tool_definitions = self.resolve_tool_definitions(skill_id);
        let context = zclaw_skills::SkillContext {
            agent_id: agent_id.to_string(),
            session_id: session_id.to_string(),
            llm: Some(self.llm.clone()),
            tool_definitions,
            ..Default::default()
        };
        let result = self.skills.execute(&zclaw_types::SkillId::new(skill_id), &context, input).await?;
        Ok(result.output)
    }

    fn get_skill_detail(&self, skill_id: &str) -> Option<zclaw_runtime::tool::SkillDetail> {
        let manifests = self.skills.manifests_snapshot();
        let manifest = manifests.get(&zclaw_types::SkillId::new(skill_id))?;
        Some(zclaw_runtime::tool::SkillDetail {
            id: manifest.id.as_str().to_string(),
            name: manifest.name.clone(),
            description: manifest.description.clone(),
            category: manifest.category.clone(),
            input_schema: manifest.input_schema.clone(),
            triggers: manifest.triggers.clone(),
            capabilities: manifest.capabilities.clone(),
        })
    }

    fn list_skill_index(&self) -> Vec<zclaw_runtime::tool::SkillIndexEntry> {
        let manifests = self.skills.manifests_snapshot();
        manifests.values()
            .filter(|m| m.enabled)
            .map(|m| zclaw_runtime::tool::SkillIndexEntry {
                id: m.id.as_str().to_string(),
                description: m.description.clone(),
                triggers: m.triggers.clone(),
            })
            .collect()
    }
}

/// Inbox wrapper for A2A message receivers that supports re-queuing
/// non-matching messages instead of dropping them.
pub(crate) struct AgentInbox {
    pub(crate) rx: tokio::sync::mpsc::Receiver<zclaw_protocols::A2aEnvelope>,
    pub(crate) pending: std::collections::VecDeque<zclaw_protocols::A2aEnvelope>,
}

impl AgentInbox {
    pub(crate) fn new(rx: tokio::sync::mpsc::Receiver<zclaw_protocols::A2aEnvelope>) -> Self {
        Self { rx, pending: std::collections::VecDeque::new() }
    }

    pub(crate) fn try_recv(&mut self) -> std::result::Result<zclaw_protocols::A2aEnvelope, tokio::sync::mpsc::error::TryRecvError> {
        if let Some(msg) = self.pending.pop_front() {
            return Ok(msg);
        }
        self.rx.try_recv()
    }

    pub(crate) async fn recv(&mut self) -> Option<zclaw_protocols::A2aEnvelope> {
        if let Some(msg) = self.pending.pop_front() {
            return Some(msg);
        }
        self.rx.recv().await
    }

    pub(crate) fn requeue(&mut self, envelope: zclaw_protocols::A2aEnvelope) {
        self.pending.push_back(envelope);
    }
}

/// Hand executor implementation for Kernel
///
/// Bridges `zclaw_runtime::tool::HandExecutor` → `zclaw_hands::HandRegistry`,
/// allowing `HandTool::execute()` to dispatch to the real Hand implementations.
pub struct KernelHandExecutor {
    hands: Arc<HandRegistry>,
}

impl KernelHandExecutor {
    pub fn new(hands: Arc<HandRegistry>) -> Self {
        Self { hands }
    }
}

#[async_trait]
impl HandExecutor for KernelHandExecutor {
    async fn execute_hand(
        &self,
        hand_id: &str,
        agent_id: &AgentId,
        input: Value,
    ) -> Result<Value> {
        let context = zclaw_hands::HandContext {
            agent_id: agent_id.clone(),
            working_dir: None,
            env: std::collections::HashMap::new(),
            timeout_secs: 300,
            callback_url: None,
        };
        let result = self.hands.execute(hand_id, &context, input).await?;
        if result.success {
            Ok(result.output)
        } else {
            Ok(json!({
                "hand_id": hand_id,
                "status": "failed",
                "error": result.error.unwrap_or_else(|| "Unknown hand execution error".to_string()),
                "output": result.output,
                "duration_ms": result.duration_ms,
            }))
        }
    }
}