//! Full-sync library sync adapter: truncate + re-insert all provider items.

use std::collections::HashMap;
use std::sync::Arc;
use std::time::Instant;

use async_trait::async_trait;
use domain::{
    Collection, ILibraryRepository, IMediaProvider, LibraryItem,
    LibrarySyncAdapter, LibrarySyncResult, MediaFilter,
};

pub struct FullSyncAdapter {
    repo: Arc<dyn ILibraryRepository>,
}

impl FullSyncAdapter {
    pub fn new(repo: Arc<dyn ILibraryRepository>) -> Self {
        Self { repo }
    }
}

#[async_trait]
impl LibrarySyncAdapter for FullSyncAdapter {
    async fn sync_provider(
        &self,
        provider: &dyn IMediaProvider,
        provider_id: &str,
    ) -> LibrarySyncResult {
        let start = Instant::now();

        // Check for running sync first
        match self.repo.is_sync_running(provider_id).await {
            Ok(true) => {
                return LibrarySyncResult {
                    provider_id: provider_id.to_string(),
                    items_found: 0,
                    duration_ms: 0,
                    error: Some("sync already running".to_string()),
                };
            }
            Err(e) => {
                return LibrarySyncResult {
                    provider_id: provider_id.to_string(),
                    items_found: 0,
                    duration_ms: 0,
                    error: Some(e.to_string()),
                };
            }
            Ok(false) => {}
        }

        let log_id = match self.repo.log_sync_start(provider_id).await {
            Ok(id) => id,
            Err(e) => {
                return LibrarySyncResult {
                    provider_id: provider_id.to_string(),
                    items_found: 0,
                    duration_ms: start.elapsed().as_millis() as u64,
                    error: Some(e.to_string()),
                };
            }
        };

        // Fetch collections for name/type enrichment — build a lookup map
        let collections: Vec<Collection> = provider.list_collections().await.unwrap_or_default();
        let collection_map: HashMap<String, &Collection> =
            collections.iter().map(|c| (c.id.clone(), c)).collect();

        // Fetch all items
        let media_items = match provider.fetch_items(&MediaFilter::default()).await {
            Ok(items) => items,
            Err(e) => {
                let result = LibrarySyncResult {
                    provider_id: provider_id.to_string(),
                    items_found: 0,
                    duration_ms: start.elapsed().as_millis() as u64,
                    error: Some(e.to_string()),
                };
                let _ = self.repo.log_sync_finish(log_id, &result).await;
                return result;
            }
        };

        let items_found = media_items.len() as u32;
        let now = chrono::Utc::now().to_rfc3339();

        let library_items: Vec<LibraryItem> = media_items
            .into_iter()
            .map(|item| {
                let raw_id = item.id.into_inner();
                let id = format!("{}::{}", provider_id, raw_id);
                // Enrich with collection name/type using the lookup map.
                let (col_name, col_type) = item.collection_id.as_deref()
                    .and_then(|cid| collection_map.get(cid))
                    .map(|c| (Some(c.name.clone()), c.collection_type.clone()))
                    .unwrap_or((None, None));
                LibraryItem {
                    id,
                    provider_id: provider_id.to_string(),
                    external_id: raw_id,
                    title: item.title,
                    content_type: item.content_type,
                    duration_secs: item.duration_secs,
                    series_name: item.series_name,
                    season_number: item.season_number,
                    episode_number: item.episode_number,
                    year: item.year,
                    genres: item.genres,
                    tags: item.tags,
                    collection_id: item.collection_id,
                    collection_name: col_name,
                    collection_type: col_type,
                    thumbnail_url: item.thumbnail_url,
                    synced_at: now.clone(),
                }
            })
            .collect();

        // Truncate + insert
        if let Err(e) = self.repo.clear_provider(provider_id).await {
            let result = LibrarySyncResult {
                provider_id: provider_id.to_string(),
                items_found: 0,
                duration_ms: start.elapsed().as_millis() as u64,
                error: Some(e.to_string()),
            };
            let _ = self.repo.log_sync_finish(log_id, &result).await;
            return result;
        }

        let result = match self.repo.upsert_items(provider_id, library_items).await {
            Ok(()) => LibrarySyncResult {
                provider_id: provider_id.to_string(),
                items_found,
                duration_ms: start.elapsed().as_millis() as u64,
                error: None,
            },
            Err(e) => LibrarySyncResult {
                provider_id: provider_id.to_string(),
                items_found: 0,
                duration_ms: start.elapsed().as_millis() as u64,
                error: Some(e.to_string()),
            },
        };

        let _ = self.repo.log_sync_finish(log_id, &result).await;
        result
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::sync::{Arc, Mutex};
    use async_trait::async_trait;
    use domain::*;

    struct MockProvider {
        items: Vec<MediaItem>,
    }

    #[async_trait]
    impl IMediaProvider for MockProvider {
        fn capabilities(&self) -> ProviderCapabilities {
            ProviderCapabilities {
                collections: true,
                series: false,
                genres: false,
                tags: false,
                decade: false,
                search: false,
                streaming_protocol: StreamingProtocol::Hls,
                rescan: false,
                transcode: false,
            }
        }
        async fn fetch_items(&self, _filter: &MediaFilter) -> DomainResult<Vec<MediaItem>> {
            Ok(self.items.clone())
        }
        async fn fetch_by_id(&self, _id: &MediaItemId) -> DomainResult<Option<MediaItem>> { Ok(None) }
        async fn get_stream_url(&self, _id: &MediaItemId, _q: &StreamQuality) -> DomainResult<String> { Ok(String::new()) }
        async fn list_collections(&self) -> DomainResult<Vec<Collection>> { Ok(vec![]) }
        async fn list_series(&self, _col: Option<&str>) -> DomainResult<Vec<SeriesSummary>> { Ok(vec![]) }
        async fn list_genres(&self, _ct: Option<&ContentType>) -> DomainResult<Vec<String>> { Ok(vec![]) }
    }

    struct SpyRepo {
        upserted: Arc<Mutex<Vec<LibraryItem>>>,
        cleared: Arc<Mutex<Vec<String>>>,
    }

    #[async_trait]
    impl ILibraryRepository for SpyRepo {
        async fn search(&self, _f: &LibrarySearchFilter) -> DomainResult<(Vec<LibraryItem>, u32)> { Ok((vec![], 0)) }
        async fn get_by_id(&self, _id: &str) -> DomainResult<Option<LibraryItem>> { Ok(None) }
        async fn list_collections(&self, _p: Option<&str>) -> DomainResult<Vec<LibraryCollection>> { Ok(vec![]) }
        async fn list_series(&self, _p: Option<&str>) -> DomainResult<Vec<String>> { Ok(vec![]) }
        async fn list_genres(&self, _ct: Option<&ContentType>, _p: Option<&str>) -> DomainResult<Vec<String>> { Ok(vec![]) }
        async fn upsert_items(&self, _pid: &str, items: Vec<LibraryItem>) -> DomainResult<()> {
            self.upserted.lock().unwrap().extend(items);
            Ok(())
        }
        async fn clear_provider(&self, pid: &str) -> DomainResult<()> {
            self.cleared.lock().unwrap().push(pid.to_string());
            Ok(())
        }
        async fn log_sync_start(&self, _pid: &str) -> DomainResult<i64> { Ok(1) }
        async fn log_sync_finish(&self, _id: i64, _r: &LibrarySyncResult) -> DomainResult<()> { Ok(()) }
        async fn latest_sync_status(&self) -> DomainResult<Vec<LibrarySyncLogEntry>> { Ok(vec![]) }
        async fn is_sync_running(&self, _pid: &str) -> DomainResult<bool> { Ok(false) }
    }

    #[tokio::test]
    async fn sync_clears_then_upserts_items() {
        let upserted = Arc::new(Mutex::new(vec![]));
        let cleared = Arc::new(Mutex::new(vec![]));
        let repo: Arc<dyn ILibraryRepository> = Arc::new(SpyRepo {
            upserted: Arc::clone(&upserted),
            cleared: Arc::clone(&cleared),
        });
        let adapter = FullSyncAdapter::new(Arc::clone(&repo));
        let provider = MockProvider {
            items: vec![MediaItem {
                id: MediaItemId::new("abc".to_string()),
                title: "Test Movie".to_string(),
                content_type: ContentType::Movie,
                duration_secs: 3600,
                description: None,
                series_name: None,
                season_number: None,
                episode_number: None,
                year: None,
                genres: vec![],
                tags: vec![],
                thumbnail_url: None,
                collection_id: None,
            }],
        };

        let result = adapter.sync_provider(&provider, "jellyfin").await;
        assert!(result.error.is_none());
        assert_eq!(result.items_found, 1);
        assert_eq!(cleared.lock().unwrap().as_slice(), &["jellyfin"]);
        assert_eq!(upserted.lock().unwrap().len(), 1);
    }
}