//! Provider import from deep link
//!
//! Handles importing provider configurations via ccswitch:// URLs.

use super::utils::{decode_base64_param, infer_homepage_from_endpoint};
use super::DeepLinkImportRequest;
use crate::error::AppError;
use crate::provider::Provider;
use crate::services::ProviderService;
use crate::store::AppState;
use crate::AppType;
use serde_json::json;
use std::str::FromStr;

/// Import a provider from a deep link request
///
/// This function:
/// 1. Validates the request
/// 2. Merges config file if provided (v3.8+)
/// 3. Converts it to a Provider structure
/// 4. Delegates to ProviderService for actual import
/// 5. Optionally sets as current provider if enabled=true
pub fn import_provider_from_deeplink(
    state: &AppState,
    request: DeepLinkImportRequest,
) -> Result<String, AppError> {
    // Verify this is a provider request
    if request.resource != "provider" {
        return Err(AppError::InvalidInput(format!(
            "Expected provider resource, got '{}'",
            request.resource
        )));
    }

    // Step 1: Merge config file if provided (v3.8+)
    let merged_request = parse_and_merge_config(&request)?;

    // Extract required fields (now as Option)
    let app_str = merged_request
        .app
        .as_ref()
        .ok_or_else(|| AppError::InvalidInput("Missing 'app' field for provider".to_string()))?;

    let api_key = merged_request.api_key.as_ref().ok_or_else(|| {
        AppError::InvalidInput("API key is required (either in URL or config file)".to_string())
    })?;

    if api_key.is_empty() {
        return Err(AppError::InvalidInput(
            "API key cannot be empty".to_string(),
        ));
    }

    let endpoint = merged_request.endpoint.as_ref().ok_or_else(|| {
        AppError::InvalidInput("Endpoint is required (either in URL or config file)".to_string())
    })?;

    if endpoint.is_empty() {
        return Err(AppError::InvalidInput(
            "Endpoint cannot be empty".to_string(),
        ));
    }

    let homepage = merged_request.homepage.as_ref().ok_or_else(|| {
        AppError::InvalidInput("Homepage is required (either in URL or config file)".to_string())
    })?;

    if homepage.is_empty() {
        return Err(AppError::InvalidInput(
            "Homepage cannot be empty".to_string(),
        ));
    }

    let name = merged_request
        .name
        .as_ref()
        .ok_or_else(|| AppError::InvalidInput("Missing 'name' field for provider".to_string()))?;

    // Parse app type
    let app_type = AppType::from_str(app_str)
        .map_err(|_| AppError::InvalidInput(format!("Invalid app type: {app_str}")))?;

    // Build provider configuration based on app type
    let mut provider = build_provider_from_request(&app_type, &merged_request)?;

    // Generate a unique ID for the provider using timestamp + sanitized name
    let timestamp = chrono::Utc::now().timestamp_millis();
    let sanitized_name = name
        .chars()
        .filter(|c| c.is_alphanumeric() || *c == '-' || *c == '_')
        .collect::<String>()
        .to_lowercase();
    provider.id = format!("{sanitized_name}-{timestamp}");

    let provider_id = provider.id.clone();

    // Use ProviderService to add the provider
    ProviderService::add(state, app_type.clone(), provider)?;

    // If enabled=true, set as current provider
    if merged_request.enabled.unwrap_or(false) {
        ProviderService::switch(state, app_type.clone(), &provider_id)?;
        log::info!("Provider '{provider_id}' set as current for {app_type:?}");
    }

    Ok(provider_id)
}

/// Build a Provider structure from a deep link request
pub(crate) fn build_provider_from_request(
    app_type: &AppType,
    request: &DeepLinkImportRequest,
) -> Result<Provider, AppError> {
    let settings_config = match app_type {
        AppType::Claude => build_claude_settings(request),
        AppType::Codex => build_codex_settings(request),
        AppType::Gemini => build_gemini_settings(request),
    };

    let provider = Provider {
        id: String::new(), // Will be generated by caller
        name: request.name.clone().unwrap_or_default(),
        settings_config,
        website_url: request.homepage.clone(),
        category: None,
        created_at: None,
        sort_index: None,
        notes: request.notes.clone(),
        meta: None,
        icon: request.icon.clone(),
        icon_color: None,
        is_proxy_target: None,
    };

    Ok(provider)
}

/// Build Claude settings configuration
fn build_claude_settings(request: &DeepLinkImportRequest) -> serde_json::Value {
    let mut env = serde_json::Map::new();
    env.insert(
        "ANTHROPIC_AUTH_TOKEN".to_string(),
        json!(request.api_key.clone().unwrap_or_default()),
    );
    env.insert(
        "ANTHROPIC_BASE_URL".to_string(),
        json!(request.endpoint.clone().unwrap_or_default()),
    );

    // Add default model if provided
    if let Some(model) = &request.model {
        env.insert("ANTHROPIC_MODEL".to_string(), json!(model));
    }

    // Add Claude-specific model fields (v3.7.1+)
    if let Some(haiku_model) = &request.haiku_model {
        env.insert(
            "ANTHROPIC_DEFAULT_HAIKU_MODEL".to_string(),
            json!(haiku_model),
        );
    }
    if let Some(sonnet_model) = &request.sonnet_model {
        env.insert(
            "ANTHROPIC_DEFAULT_SONNET_MODEL".to_string(),
            json!(sonnet_model),
        );
    }
    if let Some(opus_model) = &request.opus_model {
        env.insert(
            "ANTHROPIC_DEFAULT_OPUS_MODEL".to_string(),
            json!(opus_model),
        );
    }

    json!({ "env": env })
}

/// Build Codex settings configuration
fn build_codex_settings(request: &DeepLinkImportRequest) -> serde_json::Value {
    // Generate a safe provider name identifier
    let clean_provider_name = {
        let raw: String = request
            .name
            .clone()
            .unwrap_or_else(|| "custom".to_string())
            .chars()
            .filter(|c| !c.is_control())
            .collect();
        let lower = raw.to_lowercase();
        let mut key: String = lower
            .chars()
            .map(|c| match c {
                'a'..='z' | '0'..='9' | '_' => c,
                _ => '_',
            })
            .collect();

        // Remove leading/trailing underscores
        while key.starts_with('_') {
            key.remove(0);
        }
        while key.ends_with('_') {
            key.pop();
        }

        if key.is_empty() {
            "custom".to_string()
        } else {
            key
        }
    };

    // Model name: use deeplink model or default
    let model_name = request
        .model
        .as_deref()
        .unwrap_or("gpt-5-codex")
        .to_string();

    // Endpoint: normalize trailing slashes
    let endpoint = request
        .endpoint
        .as_deref()
        .unwrap_or("")
        .trim()
        .trim_end_matches('/')
        .to_string();

    // Build config.toml content
    let config_toml = format!(
        r#"model_provider = "{clean_provider_name}"
model = "{model_name}"
model_reasoning_effort = "high"
disable_response_storage = true

[model_providers.{clean_provider_name}]
name = "{clean_provider_name}"
base_url = "{endpoint}"
wire_api = "responses"
requires_openai_auth = true
"#
    );

    json!({
        "auth": {
            "OPENAI_API_KEY": request.api_key,
        },
        "config": config_toml
    })
}

/// Build Gemini settings configuration
fn build_gemini_settings(request: &DeepLinkImportRequest) -> serde_json::Value {
    let mut env = serde_json::Map::new();
    env.insert("GEMINI_API_KEY".to_string(), json!(request.api_key));
    env.insert(
        "GOOGLE_GEMINI_BASE_URL".to_string(),
        json!(request.endpoint),
    );

    // Add model if provided
    if let Some(model) = &request.model {
        env.insert("GEMINI_MODEL".to_string(), json!(model));
    }

    json!({ "env": env })
}

// =============================================================================
// Config Merge Logic
// =============================================================================

/// Parse and merge configuration from Base64 encoded config or remote URL
///
/// Priority: URL params > inline config > remote config
pub fn parse_and_merge_config(
    request: &DeepLinkImportRequest,
) -> Result<DeepLinkImportRequest, AppError> {
    // If no config provided, return original request
    if request.config.is_none() && request.config_url.is_none() {
        return Ok(request.clone());
    }

    // Step 1: Get config content
    let config_content = if let Some(config_b64) = &request.config {
        // Decode Base64 inline config
        let decoded = decode_base64_param("config", config_b64)?;
        String::from_utf8(decoded)
            .map_err(|e| AppError::InvalidInput(format!("Invalid UTF-8 in config: {e}")))?
    } else if let Some(_config_url) = &request.config_url {
        // Fetch remote config (TODO: implement remote fetching in next phase)
        return Err(AppError::InvalidInput(
            "Remote config URL is not yet supported. Use inline config instead.".to_string(),
        ));
    } else {
        return Ok(request.clone());
    };

    // Step 2: Parse config based on format
    let format = request.config_format.as_deref().unwrap_or("json");
    let config_value: serde_json::Value = match format {
        "json" => serde_json::from_str(&config_content)
            .map_err(|e| AppError::InvalidInput(format!("Invalid JSON config: {e}")))?,
        "toml" => {
            let toml_value: toml::Value = toml::from_str(&config_content)
                .map_err(|e| AppError::InvalidInput(format!("Invalid TOML config: {e}")))?;
            // Convert TOML to JSON for uniform processing
            serde_json::to_value(toml_value)
                .map_err(|e| AppError::Message(format!("Failed to convert TOML to JSON: {e}")))?
        }
        _ => {
            return Err(AppError::InvalidInput(format!(
                "Unsupported config format: {format}"
            )))
        }
    };

    // Step 3: Extract values from config based on app type and merge with URL params
    let mut merged = request.clone();

    // MCP, Skill and other resource types don't need config merging
    if request.resource != "provider" {
        return Ok(merged);
    }

    match request.app.as_deref().unwrap_or("") {
        "claude" => merge_claude_config(&mut merged, &config_value)?,
        "codex" => merge_codex_config(&mut merged, &config_value)?,
        "gemini" => merge_gemini_config(&mut merged, &config_value)?,
        "" => {
            // No app specified, skip merging
            return Ok(merged);
        }
        _ => {
            return Err(AppError::InvalidInput(format!(
                "Invalid app type: {:?}",
                request.app
            )))
        }
    }

    Ok(merged)
}

/// Merge Claude configuration from config file
fn merge_claude_config(
    request: &mut DeepLinkImportRequest,
    config: &serde_json::Value,
) -> Result<(), AppError> {
    let env = config
        .get("env")
        .and_then(|v| v.as_object())
        .ok_or_else(|| {
            AppError::InvalidInput("Claude config must have 'env' object".to_string())
        })?;

    // Auto-fill API key if not provided in URL
    if request.api_key.is_none() || request.api_key.as_ref().unwrap().is_empty() {
        if let Some(token) = env.get("ANTHROPIC_AUTH_TOKEN").and_then(|v| v.as_str()) {
            request.api_key = Some(token.to_string());
        }
    }

    // Auto-fill endpoint if not provided in URL
    if request.endpoint.is_none() || request.endpoint.as_ref().unwrap().is_empty() {
        if let Some(base_url) = env.get("ANTHROPIC_BASE_URL").and_then(|v| v.as_str()) {
            request.endpoint = Some(base_url.to_string());
        }
    }

    // Auto-fill homepage from endpoint if not provided
    if (request.homepage.is_none() || request.homepage.as_ref().unwrap().is_empty())
        && request.endpoint.is_some()
        && !request.endpoint.as_ref().unwrap().is_empty()
    {
        request.homepage = infer_homepage_from_endpoint(request.endpoint.as_ref().unwrap());
        if request.homepage.is_none() {
            request.homepage = Some("https://anthropic.com".to_string());
        }
    }

    // Auto-fill model fields (URL params take priority)
    if request.model.is_none() {
        request.model = env
            .get("ANTHROPIC_MODEL")
            .and_then(|v| v.as_str())
            .map(|s| s.to_string());
    }
    if request.haiku_model.is_none() {
        request.haiku_model = env
            .get("ANTHROPIC_DEFAULT_HAIKU_MODEL")
            .and_then(|v| v.as_str())
            .map(|s| s.to_string());
    }
    if request.sonnet_model.is_none() {
        request.sonnet_model = env
            .get("ANTHROPIC_DEFAULT_SONNET_MODEL")
            .and_then(|v| v.as_str())
            .map(|s| s.to_string());
    }
    if request.opus_model.is_none() {
        request.opus_model = env
            .get("ANTHROPIC_DEFAULT_OPUS_MODEL")
            .and_then(|v| v.as_str())
            .map(|s| s.to_string());
    }

    Ok(())
}

/// Merge Codex configuration from config file
fn merge_codex_config(
    request: &mut DeepLinkImportRequest,
    config: &serde_json::Value,
) -> Result<(), AppError> {
    // Auto-fill API key from auth.OPENAI_API_KEY
    if request.api_key.is_none() || request.api_key.as_ref().unwrap().is_empty() {
        if let Some(api_key) = config
            .get("auth")
            .and_then(|v| v.get("OPENAI_API_KEY"))
            .and_then(|v| v.as_str())
        {
            request.api_key = Some(api_key.to_string());
        }
    }

    // Auto-fill endpoint and model from config string
    if let Some(config_str) = config.get("config").and_then(|v| v.as_str()) {
        // Parse TOML config string to extract base_url and model
        if let Ok(toml_value) = toml::from_str::<toml::Value>(config_str) {
            // Extract base_url from model_providers section
            if request.endpoint.is_none() || request.endpoint.as_ref().unwrap().is_empty() {
                if let Some(base_url) = extract_codex_base_url(&toml_value) {
                    request.endpoint = Some(base_url);
                }
            }

            // Extract model
            if request.model.is_none() {
                if let Some(model) = toml_value.get("model").and_then(|v| v.as_str()) {
                    request.model = Some(model.to_string());
                }
            }
        }
    }

    // Auto-fill homepage from endpoint
    if (request.homepage.is_none() || request.homepage.as_ref().unwrap().is_empty())
        && request.endpoint.is_some()
        && !request.endpoint.as_ref().unwrap().is_empty()
    {
        request.homepage = infer_homepage_from_endpoint(request.endpoint.as_ref().unwrap());
        if request.homepage.is_none() {
            request.homepage = Some("https://openai.com".to_string());
        }
    }

    Ok(())
}

/// Merge Gemini configuration from config file
fn merge_gemini_config(
    request: &mut DeepLinkImportRequest,
    config: &serde_json::Value,
) -> Result<(), AppError> {
    // Gemini uses flat env structure
    if request.api_key.is_none() || request.api_key.as_ref().unwrap().is_empty() {
        if let Some(api_key) = config.get("GEMINI_API_KEY").and_then(|v| v.as_str()) {
            request.api_key = Some(api_key.to_string());
        }
    }

    if request.endpoint.is_none() || request.endpoint.as_ref().unwrap().is_empty() {
        if let Some(base_url) = config.get("GEMINI_BASE_URL").and_then(|v| v.as_str()) {
            request.endpoint = Some(base_url.to_string());
        }
    }

    if request.model.is_none() {
        request.model = config
            .get("GEMINI_MODEL")
            .and_then(|v| v.as_str())
            .map(|s| s.to_string());
    }

    // Auto-fill homepage from endpoint
    if (request.homepage.is_none() || request.homepage.as_ref().unwrap().is_empty())
        && request.endpoint.is_some()
        && !request.endpoint.as_ref().unwrap().is_empty()
    {
        request.homepage = infer_homepage_from_endpoint(request.endpoint.as_ref().unwrap());
        if request.homepage.is_none() {
            request.homepage = Some("https://ai.google.dev".to_string());
        }
    }

    Ok(())
}

/// Extract base_url from Codex TOML config
fn extract_codex_base_url(toml_value: &toml::Value) -> Option<String> {
    // Try to find base_url in model_providers section
    if let Some(providers) = toml_value.get("model_providers").and_then(|v| v.as_table()) {
        for (_key, provider) in providers.iter() {
            if let Some(base_url) = provider.get("base_url").and_then(|v| v.as_str()) {
                return Some(base_url.to_string());
            }
        }
    }
    None
}
