use std::collections::{HashMap, HashSet};

use serde::{Deserialize, Serialize};
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct Toolset {
    pub name: String,
    pub description: String,
    pub tools: Vec<String>,
    pub requires_env: Vec<String>,
}

impl Toolset {
    pub fn new(
        name: impl Into<String>,
        description: impl Into<String>,
    ) -> Self {
        Self {
            name: name.into(),
            description: description.into(),
            tools: Vec::new(),
            requires_env: Vec::new(),
        }
    }

    pub fn with_tool(mut self, tool_name: impl Into<String>) -> Self {
        self.tools.push(tool_name.into());
        self
    }

    pub fn with_tools(mut self, tool_names: impl IntoIterator<Item = impl Into<String>>) -> Self {
        self.tools.extend(tool_names.into_iter().map(Into::into));
        self
    }

    pub fn with_required_env(
        mut self,
        env_vars: impl IntoIterator<Item = impl Into<String>>,
    ) -> Self {
        self.requires_env.extend(env_vars.into_iter().map(Into::into));
        self
    }
    pub fn is_available(&self) -> bool {
        for env_var in &self.requires_env {
            if std::env::var(env_var).is_err() {
                return false;
            }
        }
        true
    }

    pub fn contains(&self, tool_name: &str) -> bool {
        self.tools.iter().any(|t| t == tool_name)
    }
}
pub mod toolset_names {
    pub const CORE: &str = "core";
    pub const TERMINAL: &str = "terminal";
    pub const WEB: &str = "web";
    pub const FILE: &str = "file";
    pub const MEMORY: &str = "memory";
    pub const VISION: &str = "vision";
    pub const SEARCH: &str = "search";
    pub const BROWSER: &str = "browser";
    pub const CODE_EXECUTION: &str = "code_execution";
    pub const DELEGATION: &str = "delegation";
}
#[derive(Clone, Debug, Default)]
pub struct ToolsetRegistry {
    toolsets: HashMap<String, Toolset>,
    tool_index: HashMap<String, String>,
}

impl ToolsetRegistry {
    pub fn new() -> Self {
        Self::default()
    }
    pub fn register(&mut self, toolset: Toolset) {
        let name = toolset.name.clone();
        for tool in &toolset.tools {
            self.tool_index.insert(tool.clone(), name.clone());
        }
        self.toolsets.insert(name, toolset);
    }

    pub fn get(&self, name: &str) -> Option<&Toolset> {
        self.toolsets.get(name)
    }
    pub fn toolset_for(&self, tool_name: &str) -> Option<&str> {
        self.tool_index.get(tool_name).map(String::as_str)
    }
    pub fn resolve_tool_names(
        &self,
        enabled: &[String],
        disabled: &[String],
        default_all: bool,
    ) -> Vec<String> {
        let mut names = HashSet::new();
        let mut denied = HashSet::new();

        for ts_name in disabled {
            if let Some(ts) = self.toolsets.get(ts_name) {
                for tool in &ts.tools {
                    denied.insert(tool.clone());
                }
            }
        }

        if enabled.is_empty() && default_all {
            for ts in self.toolsets.values() {
                if !disabled.contains(&ts.name) && ts.is_available() {
                    for tool in &ts.tools {
                        if !denied.contains(tool) {
                            names.insert(tool.clone());
                        }
                    }
                }
            }
        } else {
            for ts_name in enabled {
                if let Some(ts) = self.toolsets.get(ts_name) {
                    if ts.is_available() {
                        for tool in &ts.tools {
                            if !denied.contains(tool) {
                                names.insert(tool.clone());
                            }
                        }
                    }
                }
            }
        }

        let mut sorted: Vec<String> = names.into_iter().collect();
        sorted.sort();
        sorted
    }

    pub fn iter(&self) -> impl Iterator<Item = &Toolset> {
        self.toolsets.values()
    }

    pub fn all_tool_names(&self) -> Vec<String> {
        let mut names: Vec<String> = self.tool_index.keys().cloned().collect();
        names.sort();
        names
    }
}