use crate::instruction_presets::get_instruction_preset_library;
use crate::llm_providers::{
    get_available_providers, get_provider_metadata, LLMProviderConfig, LLMProviderType,
};
use crate::log_debug;
use anyhow::{anyhow, Result};
use dirs::config_dir;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::fs;
use std::path::PathBuf;
use std::str::FromStr;

/// Configuration structure for the Git-Iris application
#[derive(Deserialize, Serialize, Clone, Debug)]
pub struct Config {
    /// Default LLM provider
    pub default_provider: String,
    /// Provider-specific configurations
    pub providers: HashMap<String, ProviderConfig>,
    /// Flag indicating whether to use Gitmoji
    #[serde(default = "default_gitmoji")]
    pub use_gitmoji: bool,
    /// Instructions for commit messages
    #[serde(default)]
    pub instructions: String,
    #[serde(default = "default_instruction_preset")]
    pub instruction_preset: String,
    #[serde(skip)]
    pub temp_instructions: Option<String>,
    #[serde(skip)]
    pub temp_preset: Option<String>,
}

/// Provider-specific configuration structure
#[derive(Deserialize, Serialize, Clone, Debug, Default)]
pub struct ProviderConfig {
    /// API key for the provider
    pub api_key: String,
    /// Model to be used with the provider
    pub model: String,
    /// Additional parameters for the provider
    #[serde(default)]
    pub additional_params: HashMap<String, String>,
    /// Token limit, if set by the user
    pub token_limit: Option<usize>,
}

/// Default function for use_gitmoji
fn default_gitmoji() -> bool {
    true
}

// Default instruction preset to use
fn default_instruction_preset() -> String {
    "default".to_string()
}

impl Config {
    /// Load the configuration from the file
    pub fn load() -> Result<Self> {
        let config_path = Config::get_config_path()?;
        if !config_path.exists() {
            return Ok(Config::default());
        }
        let config_content = fs::read_to_string(config_path)?;
        let config: Config = toml::from_str(&config_content)?;
        log_debug!("Configuration loaded: {:?}", config);
        Ok(config)
    }

    /// Save the configuration to the file
    pub fn save(&self) -> Result<()> {
        let config_path = Config::get_config_path()?;
        let config_content = toml::to_string(self)?;
        fs::write(config_path, config_content)?;
        log_debug!("Configuration saved: {:?}", self);
        Ok(())
    }

    /// Get the path to the configuration file
    fn get_config_path() -> Result<PathBuf> {
        let mut path =
            config_dir().ok_or_else(|| anyhow!("Unable to determine config directory"))?;
        path.push("git-iris");
        std::fs::create_dir_all(&path)?;
        path.push("config.toml");
        Ok(path)
    }

    /// Check the environment for necessary prerequisites
    pub fn check_environment() -> Result<()> {
        crate::git::check_environment()?;

        // Check if we're in a git repository
        if !crate::git::is_inside_work_tree()? {
            return Err(anyhow!(
                "Not in a Git repository. Please run this command from within a Git repository."
            ));
        }

        Ok(())
    }

    pub fn set_temp_instructions(&mut self, instructions: Option<String>) {
        self.temp_instructions = instructions;
    }

    pub fn set_temp_preset(&mut self, preset: Option<String>) {
        self.temp_preset = preset;
    }

    pub fn get_effective_instructions(&self) -> String {
        let preset_library = get_instruction_preset_library();
        let preset_instructions = self
            .temp_preset
            .as_ref()
            .or(Some(&self.instruction_preset))
            .and_then(|p| preset_library.get_preset(p))
            .map(|p| p.instructions.clone())
            .unwrap_or_default();

        let custom_instructions = self
            .temp_instructions
            .as_ref()
            .unwrap_or(&self.instructions);

        format!("{}\n\n{}", preset_instructions, custom_instructions)
            .trim()
            .to_string()
    }

    /// Update the configuration with new values
    pub fn update(
        &mut self,
        provider: Option<String>,
        api_key: Option<String>,
        model: Option<String>,
        additional_params: Option<HashMap<String, String>>,
        use_gitmoji: Option<bool>,
        instructions: Option<String>,
        token_limit: Option<usize>,
    ) {
        if let Some(provider) = provider {
            self.default_provider = provider.clone();
            if !self.providers.contains_key(&provider) {
                // Only insert a new provider if it requires configuration
                let provider_type =
                    LLMProviderType::from_str(&provider).unwrap_or(LLMProviderType::OpenAI);
                if get_provider_metadata(&provider_type).requires_api_key {
                    self.providers
                        .insert(provider.clone(), ProviderConfig::default_for(&provider));
                }
            }
        }

        let provider_config = self.providers.get_mut(&self.default_provider).unwrap();

        if let Some(key) = api_key {
            provider_config.api_key = key;
        }
        if let Some(model) = model {
            provider_config.model = model;
        }
        if let Some(params) = additional_params {
            provider_config.additional_params.extend(params);
        }
        if let Some(gitmoji) = use_gitmoji {
            self.use_gitmoji = gitmoji;
        }
        if let Some(instr) = instructions {
            self.instructions = instr;
        }
        if let Some(limit) = token_limit {
            provider_config.token_limit = Some(limit);
        }

        log_debug!("Configuration updated: {:?}", self);
    }

    /// Get the configuration for a specific provider
    pub fn get_provider_config(&self, provider: &str) -> Option<&ProviderConfig> {
        self.providers.get(provider).or_else(|| {
            // If the provider is not in the config, check if it's a valid provider
            if LLMProviderType::from_str(provider).is_ok() {
                // Return None for valid providers not in the config
                // This allows the code to use default values for providers like Ollama
                None
            } else {
                // Return None for invalid providers
                None
            }
        })
    }
}

impl Default for Config {
    fn default() -> Self {
        let mut providers = HashMap::new();
        for provider in get_available_providers() {
            providers.insert(
                provider.to_string(),
                ProviderConfig::default_for(&provider.to_string()),
            );
        }

        Config {
            default_provider: get_available_providers().first().unwrap().to_string(),
            providers,
            use_gitmoji: true,
            instructions: String::new(),
            instruction_preset: default_instruction_preset(),
            temp_instructions: None,
            temp_preset: None,
        }
    }
}

impl ProviderConfig {
    /// Create a default provider configuration for a given provider
    pub fn default_for(provider: &str) -> Self {
        let provider_type =
            LLMProviderType::from_str(provider).unwrap_or_else(|_| get_available_providers()[0]);
        let metadata = get_provider_metadata(&provider_type);
        Self {
            api_key: String::new(),
            model: metadata.default_model.to_string(),
            additional_params: HashMap::new(),
            token_limit: Some(metadata.default_token_limit),
        }
    }

    /// Get the token limit for this provider configuration
    pub fn get_token_limit(&self) -> usize {
        self.token_limit.unwrap_or_else(|| {
            let provider_type = LLMProviderType::from_str(&self.model)
                .unwrap_or_else(|_| get_available_providers()[0]);
            get_provider_metadata(&provider_type).default_token_limit
        })
    }

    /// Convert to LLMProviderConfig
    pub fn to_llm_provider_config(&self) -> LLMProviderConfig {
        LLMProviderConfig {
            api_key: self.api_key.clone(),
            model: self.model.clone(),
            additional_params: self.additional_params.clone(),
        }
    }
}