//! Live configuration operations
//!
//! Handles reading and writing live configuration files for Claude, Codex, and Gemini.
//!
//! ## Common Config Runtime Merge
//!
//! When writing to live files, this module performs runtime merge of:
//! - `customConfig` (provider's settings_config) - provider-specific settings
//! - `commonConfig` (from database settings table) - shared template settings
//!
//! The merge follows the rule: customConfig overrides commonConfig.

use std::collections::HashMap;

use serde_json::{json, Value};

use crate::app_config::AppType;
use crate::codex_config::{get_codex_auth_path, get_codex_config_path};
use crate::config::{delete_file, get_claude_settings_path, read_json_file, write_json_file};
use crate::config_merge::{compute_final_json_config, compute_final_toml_config_str};
use crate::error::AppError;
use crate::provider::Provider;
use crate::services::mcp::McpService;
use crate::store::AppState;

use super::gemini_auth::{
    detect_gemini_auth_type, ensure_google_oauth_security_flag, GeminiAuthType,
};
use super::normalize_claude_models_in_value;

/// Live configuration snapshot for backup/restore
#[derive(Clone)]
#[allow(dead_code)]
pub(crate) enum LiveSnapshot {
    Claude {
        settings: Option<Value>,
    },
    Codex {
        auth: Option<Value>,
        config: Option<String>,
    },
    Gemini {
        env: Option<HashMap<String, String>>,
        config: Option<Value>,
    },
}

impl LiveSnapshot {
    #[allow(dead_code)]
    pub(crate) fn restore(&self) -> Result<(), AppError> {
        match self {
            LiveSnapshot::Claude { settings } => {
                let path = get_claude_settings_path();
                if let Some(value) = settings {
                    write_json_file(&path, value)?;
                } else if path.exists() {
                    delete_file(&path)?;
                }
            }
            LiveSnapshot::Codex { auth, config } => {
                let auth_path = get_codex_auth_path();
                let config_path = get_codex_config_path();
                if let Some(value) = auth {
                    write_json_file(&auth_path, value)?;
                } else if auth_path.exists() {
                    delete_file(&auth_path)?;
                }

                if let Some(text) = config {
                    crate::config::write_text_file(&config_path, text)?;
                } else if config_path.exists() {
                    delete_file(&config_path)?;
                }
            }
            LiveSnapshot::Gemini { env, .. } => {
                use crate::gemini_config::{
                    get_gemini_env_path, get_gemini_settings_path, write_gemini_env_atomic,
                };
                let path = get_gemini_env_path();
                if let Some(env_map) = env {
                    write_gemini_env_atomic(env_map)?;
                } else if path.exists() {
                    delete_file(&path)?;
                }

                let settings_path = get_gemini_settings_path();
                match self {
                    LiveSnapshot::Gemini {
                        config: Some(cfg), ..
                    } => {
                        write_json_file(&settings_path, cfg)?;
                    }
                    LiveSnapshot::Gemini { config: None, .. } if settings_path.exists() => {
                        delete_file(&settings_path)?;
                    }
                    _ => {}
                }
            }
        }
        Ok(())
    }
}

/// Write live configuration snapshot for a provider (raw, without common config merge)
///
/// This function writes the provider's settings_config directly to the live file.
/// Use `write_live_snapshot_with_merge` for runtime merge with common config.
pub(crate) fn write_live_snapshot(app_type: &AppType, provider: &Provider) -> Result<(), AppError> {
    write_live_snapshot_internal(app_type, provider, &provider.settings_config)
}

/// Write live configuration snapshot with common config runtime merge
///
/// This function performs runtime merge of:
/// - Provider's settings_config (custom config)
/// - Common config snippet from database (shared template)
///
/// The merge rule is: customConfig overrides commonConfig.
pub(crate) fn write_live_snapshot_with_merge(
    state: &AppState,
    app_type: &AppType,
    provider: &Provider,
) -> Result<(), AppError> {
    // Get common config snippet from database
    let common_config_snippet = state.db.get_config_snippet(app_type.as_str())?;

    // Check if common config is enabled for this app
    let common_config_enabled = provider
        .meta
        .as_ref()
        .and_then(|m| {
            m.common_config_enabled_by_app
                .as_ref()
                .and_then(|by_app| match app_type {
                    AppType::Claude => by_app.claude,
                    AppType::Codex => by_app.codex,
                    AppType::Gemini => by_app.gemini,
                    AppType::OpenCode => None, // OpenCode doesn't support common config
                })
                .or(m.common_config_enabled)
        })
        .unwrap_or(false);

    // If common config is not enabled or snippet is empty, write raw config
    if !common_config_enabled
        || common_config_snippet
            .as_ref()
            .is_none_or(|s| s.trim().is_empty())
    {
        return write_live_snapshot(app_type, provider);
    }

    let snippet = common_config_snippet.unwrap();

    // Perform runtime merge based on app type
    let final_config = match app_type {
        AppType::Claude => {
            // Claude uses JSON format
            let common_value: Value = serde_json::from_str(&snippet).unwrap_or(json!({}));
            compute_final_json_config(&provider.settings_config, &common_value, true)
        }
        AppType::Codex => {
            // Codex uses TOML for config field, JSON for auth field
            // Merge only the config field (TOML), keep auth field unchanged
            let mut merged_config = provider.settings_config.clone();
            if let Some(obj) = merged_config.as_object_mut() {
                if let Some(config_str) = obj.get("config").and_then(|v| v.as_str()) {
                    let (merged_toml, error) =
                        compute_final_toml_config_str(config_str, &snippet, true);
                    if let Some(e) = error {
                        log::warn!("Codex common config merge warning: {e}");
                    }
                    obj.insert("config".to_string(), json!(merged_toml));
                }
            }
            merged_config
        }
        AppType::Gemini => {
            // Gemini uses JSON format for env field
            let common_value: Value = serde_json::from_str(&snippet).unwrap_or(json!({}));
            let mut merged_config = provider.settings_config.clone();

            // Merge only the env field
            if let (Some(merged_obj), Some(common_obj)) =
                (merged_config.as_object_mut(), common_value.as_object())
            {
                if let Some(merged_env) = merged_obj.get_mut("env") {
                    if let (Some(merged_env_obj), Some(common_env)) = (
                        merged_env.as_object_mut(),
                        common_obj.get("env").and_then(|v| v.as_object()),
                    ) {
                        // Common env as base, custom env overrides
                        let mut final_env = common_env.clone();
                        for (k, v) in merged_env_obj.iter() {
                            final_env.insert(k.clone(), v.clone());
                        }
                        *merged_env = json!(final_env);
                    }
                }
            }
            merged_config
        }
        AppType::OpenCode => {
            // OpenCode doesn't support common config merge
            provider.settings_config.clone()
        }
    };

    log::debug!(
        "Writing live config with common config merge for {:?} provider '{}'",
        app_type,
        provider.id
    );

    // Write the merged config to live file
    let merged_provider = Provider {
        settings_config: final_config,
        ..provider.clone()
    };
    write_live_snapshot_internal(app_type, &merged_provider, &merged_provider.settings_config)
}

/// Internal function to write live configuration
fn write_live_snapshot_internal(
    app_type: &AppType,
    provider: &Provider,
    config_to_write: &Value,
) -> Result<(), AppError> {
    match app_type {
        AppType::Claude => {
            let path = get_claude_settings_path();
            write_json_file(&path, config_to_write)?;
        }
        AppType::Codex => {
            let obj = config_to_write
                .as_object()
                .ok_or_else(|| AppError::Config("Codex 供应商配置必须是 JSON 对象".to_string()))?;
            let auth = obj
                .get("auth")
                .ok_or_else(|| AppError::Config("Codex 供应商配置缺少 'auth' 字段".to_string()))?;
            let config_str = obj.get("config").and_then(|v| v.as_str()).ok_or_else(|| {
                AppError::Config("Codex 供应商配置缺少 'config' 字段或不是字符串".to_string())
            })?;

            let auth_path = get_codex_auth_path();
            write_json_file(&auth_path, auth)?;
            let config_path = get_codex_config_path();
            std::fs::write(&config_path, config_str).map_err(|e| AppError::io(&config_path, e))?;
        }
        AppType::Gemini => {
            // Delegate to write_gemini_live which handles env file writing correctly
            // Create a temporary provider with the merged config
            let temp_provider = Provider {
                settings_config: config_to_write.clone(),
                ..provider.clone()
            };
            write_gemini_live(&temp_provider)?;
        }
        AppType::OpenCode => {
            // OpenCode uses additive mode - write provider to config
            use crate::opencode_config;
            use crate::provider::OpenCodeProviderConfig;

            // Defensive check: if settings_config is a full config structure, extract provider fragment
            let config_to_write = if let Some(obj) = config_to_write.as_object() {
                // Detect full config structure (has $schema or top-level provider field)
                if obj.contains_key("$schema") || obj.contains_key("provider") {
                    log::warn!(
                        "OpenCode provider '{}' has full config structure in settings_config, attempting to extract fragment",
                        provider.id
                    );
                    // Try to extract from provider.{id}
                    obj.get("provider")
                        .and_then(|p| p.get(&provider.id))
                        .cloned()
                        .unwrap_or_else(|| provider.settings_config.clone())
                } else {
                    provider.settings_config.clone()
                }
            } else {
                provider.settings_config.clone()
            };

            // Convert settings_config to OpenCodeProviderConfig
            let opencode_config_result =
                serde_json::from_value::<OpenCodeProviderConfig>(config_to_write.clone());

            match opencode_config_result {
                Ok(config) => {
                    opencode_config::set_typed_provider(&provider.id, &config)?;
                    log::info!("OpenCode provider '{}' written to live config", provider.id);
                }
                Err(e) => {
                    log::warn!(
                        "Failed to parse OpenCode provider config for '{}': {}",
                        provider.id,
                        e
                    );
                    // Only write if config looks like a valid provider fragment
                    if config_to_write.get("npm").is_some()
                        || config_to_write.get("options").is_some()
                    {
                        opencode_config::set_provider(&provider.id, config_to_write)?;
                        log::info!(
                            "OpenCode provider '{}' written as raw JSON to live config",
                            provider.id
                        );
                    } else {
                        log::error!(
                            "OpenCode provider '{}' has invalid config structure, skipping write",
                            provider.id
                        );
                    }
                }
            }
        }
    }
    Ok(())
}

/// Sync current provider to live configuration
///
/// 使用有效的当前供应商 ID（验证过存在性）。
/// 优先从本地 settings 读取，验证后 fallback 到数据库的 is_current 字段。
/// 这确保了配置导入后无效 ID 会自动 fallback 到数据库。
///
/// This function uses `write_live_snapshot_with_merge` to perform runtime merge
/// with common config when enabled.
pub fn sync_current_to_live(state: &AppState) -> Result<(), AppError> {
    for app_type in [AppType::Claude, AppType::Codex, AppType::Gemini] {
        // Use validated effective current provider
        let current_id =
            match crate::settings::get_effective_current_provider(&state.db, &app_type)? {
                Some(id) => id,
                None => continue,
            };

        let providers = state.db.get_all_providers(app_type.as_str())?;
        if let Some(provider) = providers.get(&current_id) {
            // Use write_live_snapshot_with_merge to support common config runtime merge
            write_live_snapshot_with_merge(state, &app_type, provider)?;
        }
        // Note: get_effective_current_provider already validates existence,
        // so providers.get() should always succeed here
    }

    // MCP sync
    McpService::sync_all_enabled(state)?;

    // Skill sync
    for app_type in [AppType::Claude, AppType::Codex, AppType::Gemini] {
        if let Err(e) = crate::services::skill::SkillService::sync_to_app(&state.db, &app_type) {
            log::warn!("同步 Skill 到 {app_type:?} 失败: {e}");
            // Continue syncing other apps, don't abort
        }
    }

    Ok(())
}

/// Read current live settings for an app type
pub fn read_live_settings(app_type: AppType) -> Result<Value, AppError> {
    match app_type {
        AppType::Codex => {
            let auth_path = get_codex_auth_path();
            if !auth_path.exists() {
                return Err(AppError::localized(
                    "codex.auth.missing",
                    "Codex 配置文件不存在：缺少 auth.json",
                    "Codex configuration missing: auth.json not found",
                ));
            }
            let auth: Value = read_json_file(&auth_path)?;
            let cfg_text = crate::codex_config::read_and_validate_codex_config_text()?;
            Ok(json!({ "auth": auth, "config": cfg_text }))
        }
        AppType::Claude => {
            let path = get_claude_settings_path();
            if !path.exists() {
                return Err(AppError::localized(
                    "claude.live.missing",
                    "Claude Code 配置文件不存在",
                    "Claude settings file is missing",
                ));
            }
            read_json_file(&path)
        }
        AppType::Gemini => {
            use crate::gemini_config::{
                env_to_json, get_gemini_env_path, get_gemini_settings_path, read_gemini_env,
            };

            // Read .env file (environment variables)
            let env_path = get_gemini_env_path();
            if !env_path.exists() {
                return Err(AppError::localized(
                    "gemini.env.missing",
                    "Gemini .env 文件不存在",
                    "Gemini .env file not found",
                ));
            }

            let env_map = read_gemini_env()?;
            let env_json = env_to_json(&env_map);
            let env_obj = env_json.get("env").cloned().unwrap_or_else(|| json!({}));

            // Read settings.json file (MCP config etc.)
            let settings_path = get_gemini_settings_path();
            let config_obj = if settings_path.exists() {
                read_json_file(&settings_path)?
            } else {
                json!({})
            };

            // Return complete structure: { "env": {...}, "config": {...} }
            Ok(json!({
                "env": env_obj,
                "config": config_obj
            }))
        }
        AppType::OpenCode => {
            use crate::opencode_config::{get_opencode_config_path, read_opencode_config};

            let config_path = get_opencode_config_path();
            if !config_path.exists() {
                return Err(AppError::localized(
                    "opencode.config.missing",
                    "OpenCode 配置文件不存在",
                    "OpenCode configuration file not found",
                ));
            }

            let config = read_opencode_config()?;
            Ok(config)
        }
    }
}

/// Import default configuration from live files
///
/// Returns `Ok(true)` if a provider was actually imported,
/// `Ok(false)` if skipped (providers already exist for this app).
pub fn import_default_config(state: &AppState, app_type: AppType) -> Result<bool, AppError> {
    {
        let providers = state.db.get_all_providers(app_type.as_str())?;
        if !providers.is_empty() {
            return Ok(false); // 已有供应商，跳过
        }
    }

    let settings_config = match app_type {
        AppType::Codex => {
            let auth_path = get_codex_auth_path();
            if !auth_path.exists() {
                return Err(AppError::localized(
                    "codex.live.missing",
                    "Codex 配置文件不存在",
                    "Codex configuration file is missing",
                ));
            }
            let auth: Value = read_json_file(&auth_path)?;
            let config_str = crate::codex_config::read_and_validate_codex_config_text()?;
            json!({ "auth": auth, "config": config_str })
        }
        AppType::Claude => {
            let settings_path = get_claude_settings_path();
            if !settings_path.exists() {
                return Err(AppError::localized(
                    "claude.live.missing",
                    "Claude Code 配置文件不存在",
                    "Claude settings file is missing",
                ));
            }
            let mut v = read_json_file::<Value>(&settings_path)?;
            let _ = normalize_claude_models_in_value(&mut v);
            v
        }
        AppType::Gemini => {
            use crate::gemini_config::{
                env_to_json, get_gemini_env_path, get_gemini_settings_path, read_gemini_env,
            };

            // Read .env file (environment variables)
            let env_path = get_gemini_env_path();
            if !env_path.exists() {
                return Err(AppError::localized(
                    "gemini.live.missing",
                    "Gemini 配置文件不存在",
                    "Gemini configuration file is missing",
                ));
            }

            let env_map = read_gemini_env()?;
            let env_json = env_to_json(&env_map);
            let env_obj = env_json.get("env").cloned().unwrap_or_else(|| json!({}));

            // Read settings.json file (MCP config etc.)
            let settings_path = get_gemini_settings_path();
            let config_obj = if settings_path.exists() {
                read_json_file(&settings_path)?
            } else {
                json!({})
            };

            // Return complete structure: { "env": {...}, "config": {...} }
            json!({
                "env": env_obj,
                "config": config_obj
            })
        }
        AppType::OpenCode => {
            // OpenCode uses additive mode - import from live is not the same pattern
            // For now, return an empty config structure
            use crate::opencode_config::{get_opencode_config_path, read_opencode_config};

            let config_path = get_opencode_config_path();
            if !config_path.exists() {
                return Err(AppError::localized(
                    "opencode.live.missing",
                    "OpenCode 配置文件不存在",
                    "OpenCode configuration file is missing",
                ));
            }

            // For OpenCode, we return the full config - but note that OpenCode
            // uses additive mode, so importing defaults works differently
            read_opencode_config()?
        }
    };

    let mut provider = Provider::with_id(
        "default".to_string(),
        "default".to_string(),
        settings_config,
        None,
    );
    provider.category = Some("custom".to_string());

    state.db.save_provider(app_type.as_str(), &provider)?;
    state
        .db
        .set_current_provider(app_type.as_str(), &provider.id)?;

    Ok(true) // 真正导入了
}

/// Write Gemini live configuration with authentication handling
pub(crate) fn write_gemini_live(provider: &Provider) -> Result<(), AppError> {
    use crate::gemini_config::{
        get_gemini_settings_path, json_to_env, validate_gemini_settings_strict,
        write_gemini_env_atomic,
    };

    // One-time auth type detection to avoid repeated detection
    let auth_type = detect_gemini_auth_type(provider);

    let mut env_map = json_to_env(&provider.settings_config)?;

    // Prepare config to write to ~/.gemini/settings.json
    // Behavior:
    // - config is object: use it (merge with existing to preserve mcpServers etc.)
    // - config is null or absent: preserve existing file content
    let settings_path = get_gemini_settings_path();
    let mut config_to_write: Option<Value> = None;

    if let Some(config_value) = provider.settings_config.get("config") {
        if config_value.is_object() {
            // Merge with existing settings to preserve mcpServers and other fields
            let mut merged = if settings_path.exists() {
                read_json_file::<Value>(&settings_path).unwrap_or_else(|_| json!({}))
            } else {
                json!({})
            };

            // Merge provider config into existing settings
            if let (Some(merged_obj), Some(config_obj)) =
                (merged.as_object_mut(), config_value.as_object())
            {
                for (k, v) in config_obj {
                    merged_obj.insert(k.clone(), v.clone());
                }
            }
            config_to_write = Some(merged);
        } else if !config_value.is_null() {
            return Err(AppError::localized(
                "gemini.validation.invalid_config",
                "Gemini 配置格式错误: config 必须是对象或 null",
                "Gemini config invalid: config must be an object or null",
            ));
        }
        // config is null: don't modify existing settings.json (preserve mcpServers etc.)
    }

    // If no config specified or config is null, preserve existing file
    if config_to_write.is_none() && settings_path.exists() {
        config_to_write = Some(read_json_file(&settings_path)?);
    }

    match auth_type {
        GeminiAuthType::GoogleOfficial => {
            // Google official uses OAuth, clear env
            env_map.clear();
            write_gemini_env_atomic(&env_map)?;
        }
        GeminiAuthType::Packycode => {
            // PackyCode provider, uses API Key (strict validation on switch)
            validate_gemini_settings_strict(&provider.settings_config)?;
            write_gemini_env_atomic(&env_map)?;
        }
        GeminiAuthType::Generic => {
            // Generic provider, uses API Key (strict validation on switch)
            validate_gemini_settings_strict(&provider.settings_config)?;
            write_gemini_env_atomic(&env_map)?;
        }
    }

    if let Some(config_value) = config_to_write {
        write_json_file(&settings_path, &config_value)?;
    }

    // Set security.auth.selectedType based on auth type
    // - Google Official: OAuth mode
    // - All others: API Key mode
    match auth_type {
        GeminiAuthType::GoogleOfficial => ensure_google_oauth_security_flag(provider)?,
        GeminiAuthType::Packycode | GeminiAuthType::Generic => {
            crate::gemini_config::write_packycode_settings()?;
        }
    }

    Ok(())
}

/// Remove an OpenCode provider from the live configuration
///
/// This is specific to OpenCode's additive mode - removing a provider
/// from the opencode.json file.
pub(crate) fn remove_opencode_provider_from_live(provider_id: &str) -> Result<(), AppError> {
    use crate::opencode_config;

    // Check if OpenCode config directory exists
    if !opencode_config::get_opencode_dir().exists() {
        log::debug!("OpenCode config directory doesn't exist, skipping removal of '{provider_id}'");
        return Ok(());
    }

    opencode_config::remove_provider(provider_id)?;
    log::info!("OpenCode provider '{provider_id}' removed from live config");

    Ok(())
}

/// Import all providers from OpenCode live config to database
///
/// This imports existing providers from ~/.config/opencode/opencode.json
/// into the CC Switch database. Each provider found will be added to the
/// database with is_current set to false.
pub fn import_opencode_providers_from_live(state: &AppState) -> Result<usize, AppError> {
    use crate::opencode_config;

    let providers = opencode_config::get_typed_providers()?;
    if providers.is_empty() {
        return Ok(0);
    }

    let mut imported = 0;
    let existing = state.db.get_all_providers("opencode")?;

    for (id, config) in providers {
        // Skip if already exists in database
        if existing.contains_key(&id) {
            log::debug!("OpenCode provider '{id}' already exists in database, skipping");
            continue;
        }

        // Convert to Value for settings_config
        let settings_config = match serde_json::to_value(&config) {
            Ok(v) => v,
            Err(e) => {
                log::warn!("Failed to serialize OpenCode provider '{id}': {e}");
                continue;
            }
        };

        // Create provider
        let provider = Provider::with_id(
            id.clone(),
            config.name.clone().unwrap_or_else(|| id.clone()),
            settings_config,
            None,
        );

        // Save to database
        if let Err(e) = state.db.save_provider("opencode", &provider) {
            log::warn!("Failed to import OpenCode provider '{id}': {e}");
            continue;
        }

        imported += 1;
        log::info!("Imported OpenCode provider '{id}' from live config");
    }

    Ok(imported)
}