use std::net::SocketAddr;

use axum::{
  Json,
  extract::{ConnectInfo, Extension, Path, Query, State},
  http::StatusCode,
};
use chrono::Utc;
use pinakes_core::{
  model::{MediaId, Pagination},
  sharing::{
    Share,
    ShareActivity,
    ShareActivityAction,
    ShareId,
    ShareMutatePermissions,
    ShareNotification,
    ShareNotificationType,
    SharePermissions,
    ShareRecipient,
    ShareTarget,
    ShareViewPermissions,
    generate_share_token,
    hash_share_password,
    verify_share_password,
  },
  users::UserId,
};
use uuid::Uuid;

use crate::{
  auth::resolve_user_id,
  dto::{
    AccessSharedRequest,
    BatchDeleteSharesRequest,
    CreateShareRequest,
    MediaResponse,
    PaginationParams,
    ShareActivityResponse,
    ShareNotificationResponse,
    ShareResponse,
    SharedContentResponse,
    UpdateShareRequest,
  },
  error::{ApiError, ApiResult},
  state::AppState,
};

/// Create a new share
/// POST /api/shares
pub async fn create_share(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Json(req): Json<CreateShareRequest>,
) -> ApiResult<Json<ShareResponse>> {
  let config = state.config.read().await;
  if !config.sharing.enabled() {
    return Err(ApiError::bad_request("Sharing is not enabled"));
  }

  // Validate public links are allowed
  if req.recipient_type == "public_link" && !config.sharing.allow_public_links()
  {
    return Err(ApiError::bad_request("Public links are not allowed"));
  }

  // Enforce password requirement for public links if configured
  if req.recipient_type == "public_link"
    && config.sharing.require_public_link_password
    && req.password.is_none()
  {
    return Err(ApiError::bad_request(
      "Public links require a password per server policy",
    ));
  }
  drop(config);

  let owner_id = resolve_user_id(&state.storage, &username).await?;

  // Parse target
  let target_id: Uuid = req
    .target_id
    .parse()
    .map_err(|_| ApiError::bad_request("Invalid target_id"))?;

  let target = match req.target_type.as_str() {
    "media" => {
      ShareTarget::Media {
        media_id: MediaId(target_id),
      }
    },
    "collection" => {
      ShareTarget::Collection {
        collection_id: target_id,
      }
    },
    "tag" => ShareTarget::Tag { tag_id: target_id },
    "saved_search" => {
      ShareTarget::SavedSearch {
        search_id: target_id,
      }
    },
    _ => return Err(ApiError::bad_request("Invalid target_type")),
  };

  // Parse recipient
  let recipient = match req.recipient_type.as_str() {
    "public_link" => {
      let token = generate_share_token();
      let password_hash = req
        .password
        .as_ref()
        .map(|p| hash_share_password(p))
        .transpose()
        .map_err(ApiError)?;
      ShareRecipient::PublicLink {
        token,
        password_hash,
      }
    },
    "user" => {
      let recipient_user_id = req.recipient_user_id.ok_or_else(|| {
        ApiError::bad_request("recipient_user_id required for user share")
      })?;
      ShareRecipient::User {
        user_id: UserId(recipient_user_id),
      }
    },
    "group" => {
      let group_id = req.recipient_group_id.ok_or_else(|| {
        ApiError::bad_request("recipient_group_id required for group share")
      })?;
      ShareRecipient::Group { group_id }
    },
    _ => return Err(ApiError::bad_request("Invalid recipient_type")),
  };

  // Parse permissions
  let permissions = if let Some(perms) = req.permissions {
    SharePermissions {
      view:   ShareViewPermissions {
        can_view:     perms.can_view.unwrap_or(true),
        can_download: perms.can_download.unwrap_or(false),
        can_reshare:  perms.can_reshare.unwrap_or(false),
      },
      mutate: ShareMutatePermissions {
        can_edit:   perms.can_edit.unwrap_or(false),
        can_delete: perms.can_delete.unwrap_or(false),
        can_add:    perms.can_add.unwrap_or(false),
      },
    }
  } else {
    SharePermissions::view_only()
  };

  // Calculate expiration
  let expires_at = req
    .expires_in_hours
    .map(|hours| Utc::now() + chrono::Duration::hours(hours as i64));

  let share = Share {
    id: ShareId(Uuid::now_v7()),
    target,
    owner_id,
    recipient,
    permissions,
    note: req.note,
    expires_at,
    access_count: 0,
    last_accessed: None,
    inherit_to_children: req.inherit_to_children.unwrap_or(true),
    parent_share_id: None,
    created_at: Utc::now(),
    updated_at: Utc::now(),
  };

  let created =
    state.storage.create_share(&share).await.map_err(|e| {
      ApiError::internal(format!("Failed to create share: {e}"))
    })?;

  // Send notification to recipient if it's a user share
  if let ShareRecipient::User { user_id } = &created.recipient {
    let notification = ShareNotification {
      id:                Uuid::now_v7(),
      user_id:           *user_id,
      share_id:          created.id,
      notification_type: ShareNotificationType::NewShare,
      is_read:           false,
      created_at:        Utc::now(),
    };

    if let Err(e) = state.storage.create_share_notification(&notification).await
    {
      tracing::warn!(error = %e, "failed to send share notification");
    }
  }

  Ok(Json(created.into()))
}

/// List outgoing shares (shares I created)
/// GET /api/shares/outgoing
pub async fn list_outgoing(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Query(params): Query<PaginationParams>,
) -> ApiResult<Json<Vec<ShareResponse>>> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  let pagination = Pagination {
    offset: params.offset.unwrap_or(0),
    limit:  params.limit.unwrap_or(50).min(1000),
    sort:   params.sort,
  };

  let shares = state
    .storage
    .list_shares_by_owner(user_id, &pagination)
    .await
    .map_err(|e| ApiError::internal(format!("Failed to list shares: {e}")))?;

  Ok(Json(shares.into_iter().map(Into::into).collect()))
}

/// List incoming shares (shares shared with me)
/// GET /api/shares/incoming
pub async fn list_incoming(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Query(params): Query<PaginationParams>,
) -> ApiResult<Json<Vec<ShareResponse>>> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  let pagination = Pagination {
    offset: params.offset.unwrap_or(0),
    limit:  params.limit.unwrap_or(50).min(1000),
    sort:   params.sort,
  };

  let shares = state
    .storage
    .list_shares_for_user(user_id, &pagination)
    .await
    .map_err(|e| ApiError::internal(format!("Failed to list shares: {e}")))?;

  Ok(Json(shares.into_iter().map(Into::into).collect()))
}

/// Get share details
/// GET /api/shares/{id}
pub async fn get_share(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Path(id): Path<Uuid>,
) -> ApiResult<Json<ShareResponse>> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  let share = state
    .storage
    .get_share(ShareId(id))
    .await
    .map_err(|e| ApiError::not_found(format!("Share not found: {e}")))?;

  // Check authorization
  let is_owner = share.owner_id == user_id;
  let is_recipient = match &share.recipient {
    ShareRecipient::User {
      user_id: recipient_id,
    } => *recipient_id == user_id,
    _ => false,
  };

  if !is_owner && !is_recipient {
    return Err(ApiError::forbidden("Not authorized to view this share"));
  }

  Ok(Json(share.into()))
}

/// Update a share
/// PATCH /api/shares/{id}
pub async fn update_share(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Path(id): Path<Uuid>,
  Json(req): Json<UpdateShareRequest>,
) -> ApiResult<Json<ShareResponse>> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  let mut share = state
    .storage
    .get_share(ShareId(id))
    .await
    .map_err(|e| ApiError::not_found(format!("Share not found: {e}")))?;

  // Only owner can update
  if share.owner_id != user_id {
    return Err(ApiError::forbidden("Only the owner can update this share"));
  }

  // Update fields
  if let Some(perms) = req.permissions {
    share.permissions = SharePermissions {
      view:   ShareViewPermissions {
        can_view:     perms.can_view.unwrap_or(share.permissions.view.can_view),
        can_download: perms
          .can_download
          .unwrap_or(share.permissions.view.can_download),
        can_reshare:  perms
          .can_reshare
          .unwrap_or(share.permissions.view.can_reshare),
      },
      mutate: ShareMutatePermissions {
        can_edit:   perms.can_edit.unwrap_or(share.permissions.mutate.can_edit),
        can_delete: perms
          .can_delete
          .unwrap_or(share.permissions.mutate.can_delete),
        can_add:    perms.can_add.unwrap_or(share.permissions.mutate.can_add),
      },
    };
  }

  if let Some(note) = req.note {
    share.note = Some(note);
  }

  if let Some(expires_at) = req.expires_at {
    share.expires_at = Some(expires_at);
  }

  if let Some(inherit) = req.inherit_to_children {
    share.inherit_to_children = inherit;
  }

  share.updated_at = Utc::now();

  let updated =
    state.storage.update_share(&share).await.map_err(|e| {
      ApiError::internal(format!("Failed to update share: {e}"))
    })?;

  // Notify recipient of update
  if let ShareRecipient::User { user_id } = &updated.recipient {
    let notification = ShareNotification {
      id:                Uuid::now_v7(),
      user_id:           *user_id,
      share_id:          updated.id,
      notification_type: ShareNotificationType::ShareUpdated,
      is_read:           false,
      created_at:        Utc::now(),
    };
    if let Err(e) = state.storage.create_share_notification(&notification).await
    {
      tracing::warn!(error = %e, "failed to send share update notification");
    }
  }

  Ok(Json(updated.into()))
}

/// Delete (revoke) a share
/// DELETE /api/shares/{id}
pub async fn delete_share(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Path(id): Path<Uuid>,
) -> ApiResult<StatusCode> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  let share = state
    .storage
    .get_share(ShareId(id))
    .await
    .map_err(|e| ApiError::not_found(format!("Share not found: {e}")))?;

  // Only owner can delete
  if share.owner_id != user_id {
    return Err(ApiError::forbidden("Only the owner can revoke this share"));
  }

  // Notify recipient before deletion
  if let ShareRecipient::User { user_id } = &share.recipient {
    let notification = ShareNotification {
      id:                Uuid::now_v7(),
      user_id:           *user_id,
      share_id:          share.id,
      notification_type: ShareNotificationType::ShareRevoked,
      is_read:           false,
      created_at:        Utc::now(),
    };
    if let Err(e) = state.storage.create_share_notification(&notification).await
    {
      tracing::warn!(error = %e, "failed to send share revocation notification");
    }
  }

  state
    .storage
    .delete_share(ShareId(id))
    .await
    .map_err(|e| ApiError::internal(format!("Failed to delete share: {e}")))?;

  Ok(StatusCode::NO_CONTENT)
}

/// Batch delete shares
/// POST /api/shares/batch/delete
pub async fn batch_delete(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Json(req): Json<BatchDeleteSharesRequest>,
) -> ApiResult<Json<serde_json::Value>> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  let share_ids: Vec<ShareId> =
    req.share_ids.into_iter().map(ShareId).collect();

  // Verify ownership of all shares
  for share_id in &share_ids {
    let share = state
      .storage
      .get_share(*share_id)
      .await
      .map_err(|e| ApiError::not_found(format!("Share not found: {e}")))?;

    if share.owner_id != user_id {
      return Err(ApiError::forbidden(format!(
        "Not authorized to delete share {}",
        share_id.0
      )));
    }
  }

  let deleted = state
    .storage
    .batch_delete_shares(&share_ids)
    .await
    .map_err(|e| ApiError::internal(format!("Failed to batch delete: {e}")))?;

  Ok(Json(serde_json::json!({ "deleted": deleted })))
}

/// Access a public shared resource
/// GET /api/shared/{token}
pub async fn access_shared(
  State(state): State<AppState>,
  Path(token): Path<String>,
  Query(params): Query<AccessSharedRequest>,
  ConnectInfo(addr): ConnectInfo<SocketAddr>,
) -> ApiResult<Json<SharedContentResponse>> {
  let share = state
    .storage
    .get_share_by_token(&token)
    .await
    .map_err(|e| ApiError::not_found(format!("Share not found: {e}")))?;

  // Check expiration
  if let Some(expires_at) = share.expires_at
    && Utc::now() > expires_at
  {
    return Err(ApiError::not_found("Share has expired"));
  }

  // Check password if required
  if let ShareRecipient::PublicLink {
    password_hash: Some(hash),
    ..
  } = &share.recipient
  {
    let provided_password = params
      .password
      .as_ref()
      .ok_or_else(|| ApiError::unauthorized("Password required"))?;

    if !verify_share_password(provided_password, hash) {
      // Log failed attempt
      let activity = ShareActivity {
        id:        Uuid::now_v7(),
        share_id:  share.id,
        actor_id:  None,
        actor_ip:  Some(addr.ip().to_string()),
        action:    ShareActivityAction::PasswordFailed,
        details:   None,
        timestamp: Utc::now(),
      };
      if let Err(e) = state.storage.record_share_activity(&activity).await {
        tracing::warn!(error = %e, "failed to record share activity");
      }

      return Err(ApiError::unauthorized("Invalid password"));
    }
  }

  // Record access
  state
    .storage
    .record_share_access(share.id)
    .await
    .map_err(|e| ApiError::internal(format!("Failed to record access: {e}")))?;

  // Log the access
  let activity = ShareActivity {
    id:        Uuid::now_v7(),
    share_id:  share.id,
    actor_id:  None,
    actor_ip:  Some(addr.ip().to_string()),
    action:    ShareActivityAction::Accessed,
    details:   None,
    timestamp: Utc::now(),
  };
  let _ = state.storage.record_share_activity(&activity).await;

  // Return the shared content
  let roots = state.config.read().await.directories.roots.clone();
  match &share.target {
    ShareTarget::Media { media_id } => {
      let item = state
        .storage
        .get_media(*media_id)
        .await
        .map_err(|e| ApiError::not_found(format!("Media not found: {e}")))?;

      Ok(Json(SharedContentResponse::Single(MediaResponse::new(
        item, &roots,
      ))))
    },
    ShareTarget::Collection { collection_id } => {
      let members = state
        .storage
        .get_collection_members(*collection_id)
        .await
        .map_err(|e| {
          ApiError::not_found(format!("Collection not found: {e}"))
        })?;

      let items: Vec<MediaResponse> = members
        .into_iter()
        .map(|item| MediaResponse::new(item, &roots))
        .collect();

      Ok(Json(SharedContentResponse::Multiple { items }))
    },
    ShareTarget::Tag { tag_id } => {
      let tag = state
        .storage
        .get_tag(*tag_id)
        .await
        .map_err(|e| ApiError::not_found(format!("Tag not found: {e}")))?;

      let request = pinakes_core::search::SearchRequest {
        query:      pinakes_core::search::SearchQuery::TagFilter(
          tag.name.clone(),
        ),
        sort:       pinakes_core::search::SortOrder::default(),
        pagination: Pagination::new(0, 100, None),
      };

      let results = state
        .storage
        .search(&request)
        .await
        .map_err(|e| ApiError::internal(format!("Search failed: {e}")))?;

      let items: Vec<MediaResponse> = results
        .items
        .into_iter()
        .map(|item| MediaResponse::new(item, &roots))
        .collect();

      Ok(Json(SharedContentResponse::Multiple { items }))
    },
    ShareTarget::SavedSearch { search_id } => {
      let saved =
        state
          .storage
          .get_saved_search(*search_id)
          .await
          .map_err(|e| {
            ApiError::not_found(format!("Saved search not found: {e}"))
          })?;

      let parsed_query = pinakes_core::search::parse_search_query(&saved.query)
        .map_err(|e| {
          ApiError::internal(format!("Failed to parse search query: {e}"))
        })?;

      let request = pinakes_core::search::SearchRequest {
        query:      parsed_query,
        sort:       pinakes_core::search::SortOrder::default(),
        pagination: Pagination::new(0, 100, None),
      };

      let results = state
        .storage
        .search(&request)
        .await
        .map_err(|e| ApiError::internal(format!("Search failed: {e}")))?;

      let items: Vec<MediaResponse> = results
        .items
        .into_iter()
        .map(|item| MediaResponse::new(item, &roots))
        .collect();

      Ok(Json(SharedContentResponse::Multiple { items }))
    },
  }
}

/// Get share activity log
/// GET /api/shares/{id}/activity
pub async fn get_activity(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Path(id): Path<Uuid>,
  Query(params): Query<PaginationParams>,
) -> ApiResult<Json<Vec<ShareActivityResponse>>> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  let share = state
    .storage
    .get_share(ShareId(id))
    .await
    .map_err(|e| ApiError::not_found(format!("Share not found: {e}")))?;

  // Only owner can view activity
  if share.owner_id != user_id {
    return Err(ApiError::forbidden(
      "Only the owner can view share activity",
    ));
  }

  let pagination = Pagination {
    offset: params.offset.unwrap_or(0),
    limit:  params.limit.unwrap_or(50).min(1000),
    sort:   params.sort,
  };

  let activity = state
    .storage
    .get_share_activity(ShareId(id), &pagination)
    .await
    .map_err(|e| ApiError::internal(format!("Failed to get activity: {e}")))?;

  Ok(Json(activity.into_iter().map(Into::into).collect()))
}

/// Get unread share notifications
/// GET /api/notifications/shares
pub async fn get_notifications(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
) -> ApiResult<Json<Vec<ShareNotificationResponse>>> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  let notifications = state
    .storage
    .get_unread_notifications(user_id)
    .await
    .map_err(|e| {
      ApiError::internal(format!("Failed to get notifications: {e}"))
    })?;

  Ok(Json(notifications.into_iter().map(Into::into).collect()))
}

/// Mark a notification as read
/// POST /api/notifications/shares/{id}/read
pub async fn mark_notification_read(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
  Path(id): Path<Uuid>,
) -> ApiResult<StatusCode> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  state
    .storage
    .mark_notification_read(id, user_id)
    .await
    .map_err(|e| ApiError::internal(format!("Failed to mark as read: {e}")))?;

  Ok(StatusCode::OK)
}

/// Mark all notifications as read
/// POST /api/notifications/shares/read-all
pub async fn mark_all_read(
  State(state): State<AppState>,
  Extension(username): Extension<String>,
) -> ApiResult<StatusCode> {
  let user_id = resolve_user_id(&state.storage, &username).await?;
  state
    .storage
    .mark_all_notifications_read(user_id)
    .await
    .map_err(|e| {
      ApiError::internal(format!("Failed to mark all as read: {e}"))
    })?;

  Ok(StatusCode::OK)
}