use std::{collections::HashMap, sync::Arc};

use axum::{
  Json,
  extract::{Path, State},
};
use pinakes_core::plugin::PluginManager;

use crate::{
  dto::{
    InstallPluginRequest,
    PluginEventRequest,
    PluginResponse,
    PluginUiPageEntry,
    PluginUiWidgetEntry,
    TogglePluginRequest,
  },
  error::ApiError,
  state::AppState,
};

fn require_plugin_manager(
  state: &AppState,
) -> Result<Arc<PluginManager>, ApiError> {
  state.plugin_manager.clone().ok_or_else(|| {
    ApiError(pinakes_core::error::PinakesError::InvalidOperation(
      "Plugin system is not enabled".to_string(),
    ))
  })
}

/// List all installed plugins
pub async fn list_plugins(
  State(state): State<AppState>,
) -> Result<Json<Vec<PluginResponse>>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;

  let plugins = plugin_manager.list_plugins().await;
  let mut responses = Vec::with_capacity(plugins.len());
  for meta in plugins {
    let enabled = plugin_manager.is_plugin_enabled(&meta.id).await;
    responses.push(PluginResponse::new(meta, enabled));
  }
  Ok(Json(responses))
}

/// Get a specific plugin by ID
pub async fn get_plugin(
  State(state): State<AppState>,
  Path(id): Path<String>,
) -> Result<Json<PluginResponse>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;

  let plugin = plugin_manager.get_plugin(&id).await.ok_or_else(|| {
    ApiError(pinakes_core::error::PinakesError::NotFound(format!(
      "Plugin not found: {id}"
    )))
  })?;

  let enabled = plugin_manager.is_plugin_enabled(&id).await;
  Ok(Json(PluginResponse::new(plugin, enabled)))
}

/// Install a plugin from URL or file path
pub async fn install_plugin(
  State(state): State<AppState>,
  Json(req): Json<InstallPluginRequest>,
) -> Result<Json<PluginResponse>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;

  let plugin_id =
    plugin_manager
      .install_plugin(&req.source)
      .await
      .map_err(|e| {
        ApiError(pinakes_core::error::PinakesError::InvalidOperation(
          format!("Failed to install plugin: {e}"),
        ))
      })?;

  let plugin =
    plugin_manager.get_plugin(&plugin_id).await.ok_or_else(|| {
      ApiError(pinakes_core::error::PinakesError::NotFound(
        "Plugin installed but not found".to_string(),
      ))
    })?;

  let enabled = plugin_manager.is_plugin_enabled(&plugin_id).await;
  Ok(Json(PluginResponse::new(plugin, enabled)))
}

/// Uninstall a plugin
pub async fn uninstall_plugin(
  State(state): State<AppState>,
  Path(id): Path<String>,
) -> Result<Json<serde_json::Value>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;

  plugin_manager.uninstall_plugin(&id).await.map_err(|e| {
    ApiError(pinakes_core::error::PinakesError::InvalidOperation(
      format!("Failed to uninstall plugin: {e}"),
    ))
  })?;

  Ok(Json(serde_json::json!({"uninstalled": true})))
}

/// Enable or disable a plugin
pub async fn toggle_plugin(
  State(state): State<AppState>,
  Path(id): Path<String>,
  Json(req): Json<TogglePluginRequest>,
) -> Result<Json<serde_json::Value>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;

  if req.enabled {
    plugin_manager.enable_plugin(&id).await.map_err(|e| {
      ApiError(pinakes_core::error::PinakesError::InvalidOperation(
        format!("Failed to enable plugin: {e}"),
      ))
    })?;
  } else {
    plugin_manager.disable_plugin(&id).await.map_err(|e| {
      ApiError(pinakes_core::error::PinakesError::InvalidOperation(
        format!("Failed to disable plugin: {e}"),
      ))
    })?;
  }

  // Re-discover capabilities after toggle so cached data stays current
  if let Some(ref pipeline) = state.plugin_pipeline
    && let Err(e) = pipeline.discover_capabilities().await
  {
    tracing::warn!(
      plugin_id = %id,
      error = %e,
      "failed to re-discover capabilities after plugin toggle"
    );
  }

  Ok(Json(serde_json::json!({
      "id": id,
      "enabled": req.enabled
  })))
}

/// List all UI pages provided by loaded plugins
pub async fn list_plugin_ui_pages(
  State(state): State<AppState>,
) -> Result<Json<Vec<PluginUiPageEntry>>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;

  let pages = plugin_manager.list_ui_pages_with_endpoints().await;
  let entries = pages
    .into_iter()
    .map(|(plugin_id, page, allowed_endpoints)| {
      PluginUiPageEntry {
        plugin_id,
        page,
        allowed_endpoints,
      }
    })
    .collect();
  Ok(Json(entries))
}

/// List all UI widgets provided by loaded plugins
pub async fn list_plugin_ui_widgets(
  State(state): State<AppState>,
) -> Result<Json<Vec<PluginUiWidgetEntry>>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;

  let widgets = plugin_manager.list_ui_widgets().await;
  let entries = widgets
    .into_iter()
    .map(|(plugin_id, widget)| PluginUiWidgetEntry { plugin_id, widget })
    .collect();
  Ok(Json(entries))
}

/// Receive a plugin event emitted from the UI and dispatch it to interested
/// server-side event-handler plugins via the pipeline.
pub async fn emit_plugin_event(
  State(state): State<AppState>,
  Json(req): Json<PluginEventRequest>,
) -> Result<Json<serde_json::Value>, ApiError> {
  tracing::info!(event = %req.event, "plugin UI event received");
  state.emit_plugin_event(&req.event, &req.payload);
  Ok(Json(
    serde_json::json!({ "received": true, "event": req.event }),
  ))
}

/// List merged CSS custom property overrides from all enabled plugins
pub async fn list_plugin_ui_theme_extensions(
  State(state): State<AppState>,
) -> Result<Json<HashMap<String, String>>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;
  Ok(Json(plugin_manager.list_ui_theme_extensions().await))
}

/// Reload a plugin (for development)
pub async fn reload_plugin(
  State(state): State<AppState>,
  Path(id): Path<String>,
) -> Result<Json<serde_json::Value>, ApiError> {
  let plugin_manager = require_plugin_manager(&state)?;

  plugin_manager.reload_plugin(&id).await.map_err(|e| {
    ApiError(pinakes_core::error::PinakesError::InvalidOperation(
      format!("Failed to reload plugin: {e}"),
    ))
  })?;

  // Re-discover capabilities after reload so cached data stays current
  if let Some(ref pipeline) = state.plugin_pipeline
    && let Err(e) = pipeline.discover_capabilities().await
  {
    tracing::warn!(
      plugin_id = %id,
      error = %e,
      "failed to re-discover capabilities after plugin reload"
    );
  }

  Ok(Json(serde_json::json!({"reloaded": true})))
}