use crate::models::*;
use crate::search::MemoryIndex;
use crate::store::Store;
use std::collections::HashMap;
use std::path::PathBuf;
use std::sync::{Arc, RwLock};

#[derive(Clone, Debug, serde::Serialize, serde::Deserialize)]
pub struct GenericEvent {
    pub topic: String,
    pub session_id: Option<String>,
    pub payload: serde_json::Value,
}

pub struct MemoryState {
    pub base_dir: PathBuf,
    pub clipboard_watch_mode: tokio::sync::RwLock<bool>,
    pub graph: Store<KnowledgeGraph>,
    pub search_index: RwLock<MemoryIndex>,
    pub ledger: Store<Vec<CodeChange>>,
    pub sticky: Store<Vec<StickyNote>>,
    pub tasks: Store<Vec<Task>>,
    pub snippets: Store<Vec<Snippet>>,
    pub adrs: Store<Vec<Adr>>,
    pub prefs: Store<HashMap<String, Preference>>,
    pub error_fixes: Store<Vec<ErrorFix>>,
    pub pinned_files: Store<Vec<PinnedFile>>,
    pub session_summaries: Store<Vec<SessionSummary>>,
    pub handoff_memos: Store<Vec<HandoffMemo>>,
    pub env_fingerprints: Store<HashMap<String, EnvFingerprint>>,
    pub env_requirements: Store<Vec<EnvRequirement>>,
    pub milestones: Store<Vec<Milestone>>,
    pub environments: Store<Vec<EnvironmentDetail>>,
    pub pr_checklists: Store<Vec<PrChecklistItem>>,
    pub tech_debts: Store<Vec<TechDebt>>,
    pub gates: Store<Vec<GateRecord>>,
    pub context_workspaces: Store<Vec<ContextWorkspace>>,
    pub recent_activities: Store<std::collections::VecDeque<serde_json::Value>>,
    pub terminal_history: Store<std::collections::VecDeque<TerminalHistory>>,
    pub activity_tx: tokio::sync::broadcast::Sender<String>,
    pub event_bus_tx: tokio::sync::broadcast::Sender<GenericEvent>,
}

impl MemoryState {
    pub fn new(base_dir_str: &str) -> Self {
        let base = std::path::PathBuf::from(base_dir_str);
        std::fs::create_dir_all(&base).expect("Failed to create store dir");

        let db = crate::db::init_redb(&base);

        Self {
            clipboard_watch_mode: tokio::sync::RwLock::new(false),
            graph: Store::new("knowledge_graph_master", db.clone()),
            base_dir: base.clone(),
            search_index: RwLock::new(match crate::search::MemoryIndex::new(&base) {
                Ok(idx) => idx,
                Err(e) => {
                    let log_path = dirs::home_dir()
                        .unwrap_or_default()
                        .join(".gemini/mcp_memory/daemon_error.log");
                    let _ =
                        std::fs::write(&log_path, format!("Failed to create MemoryIndex: {}\n", e));
                    std::process::exit(1);
                }
            }),
            ledger: Store::new("audit_ledger", db.clone()),
            sticky: Store::new("sticky_notes", db.clone()),
            tasks: Store::new("tasks", db.clone()),
            snippets: Store::new("snippets", db.clone()),
            adrs: Store::new("adrs", db.clone()),
            prefs: Store::new("preferences", db.clone()),
            error_fixes: Store::new("error_fixes", db.clone()),
            pinned_files: Store::new("pinned_files", db.clone()),
            session_summaries: Store::new("session_summaries", db.clone()),
            handoff_memos: Store::new("handoff_memos", db.clone()),
            env_fingerprints: Store::new("env_fingerprints", db.clone()),
            env_requirements: Store::new("env_requirements", db.clone()),
            milestones: Store::new("milestones", db.clone()),
            environments: Store::new("environments", db.clone()),
            pr_checklists: Store::new("pr_checklists", db.clone()),
            tech_debts: Store::new("tech_debts", db.clone()),
            gates: Store::new("gates", db.clone()),
            context_workspaces: Store::new("context_workspaces", db.clone()),
            recent_activities: Store::new("recent_activities", db.clone()),
            terminal_history: Store::new("terminal_history", db.clone()),
            activity_tx: tokio::sync::broadcast::channel(100).0,
            event_bus_tx: tokio::sync::broadcast::channel(1000).0,
        }
    }

    pub fn broadcast_activity(&self, message: &str) {
        let time = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap_or_default()
            .as_millis() as u64;

        let item = serde_json::json!({
            "time": time,
            "message": message
        });

        self.recent_activities.modify(|activities| {
            activities.push_back(item.clone());
            if activities.len() > 100 {
                activities.pop_front();
            }
        });

        let payload = serde_json::json!({
            "jsonrpc": "2.0",
            "method": "notifications/activity",
            "params": item
        })
        .to_string();
        let _ = self.activity_tx.send(payload);
    }

    pub fn read_graph<F, R>(&self, f: F) -> R
    where
        F: FnOnce(&KnowledgeGraph) -> R,
    {
        self.graph.read_with(f)
    }

    pub fn modify_graph<F: FnOnce(&mut KnowledgeGraph)>(&self, update_fn: F) {
        self.graph.modify(update_fn);
    }

    pub fn get_search_index(&self) -> MemoryIndex {
        self.search_index
            .read()
            .unwrap_or_else(|e| e.into_inner())
            .clone()
    }

    pub async fn rebuild_index(self: &Arc<Self>) {
        let idx = self.search_index.read().unwrap().clone();
        idx.delete_all();

        let entities: Vec<_> = self
            .graph
            .read_with(|g| g.entities.values().cloned().collect());
        let tasks = self.tasks.read_with(|t| t.clone());
        let snippets = self.snippets.read_with(|s| s.clone());
        let adrs = self.adrs.read_with(|a| a.clone());

        println!(
            "rebuild_index: found {} entities, {} tasks",
            entities.len(),
            tasks.len()
        );

        let idx_clone = idx.clone();
        tokio::task::spawn_blocking(move || {
            println!("spawn_blocking started in rebuild_index");
            for e in entities {
                idx_clone.add_entity_sync(&e);
            }
            for task in tasks {
                idx_clone.add_task_sync(&task);
            }
            for snippet in snippets {
                idx_clone.add_snippet_sync(&snippet);
            }
            for adr in adrs {
                idx_clone.add_adr_sync(&adr);
            }
        })
        .await
        .unwrap_or_else(|e| {
            tracing::error!("Failed to join tantivy index rebuild thread: {}", e);
        });

        let _ = idx.commit().await;
        if let Ok(mut w) = self.search_index.write() {
            *w = idx;
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use tempfile::tempdir;

    #[tokio::test]
    async fn test_memory_state_initialization() {
        let dir = tempdir().unwrap();
        let state = MemoryState::new(dir.path().to_str().unwrap());

        // Ensure state fields are properly initialized
        assert_eq!(state.base_dir, dir.path());

        // Write a test value
        state.tasks.modify(|tasks| {
            tasks.push(Task {
                id: "123".to_string(),
                title: "Test Task".to_string(),
                description: "".to_string(),
                status: "active".to_string(),
                created_at: 0,
                updated_at: 0,
                dependencies: vec![],
                acceptance_criteria: vec![],
                git_branch: None,
                parent_id: None,
                expires_at: None,
            });
        });

        // Ensure it is saved
        state.tasks.read_with(|tasks| {
            assert_eq!(tasks.len(), 1);
            assert_eq!(tasks[0].id, "123");
        });

        // Test rebuild index
        let arc_state = Arc::new(state);
        arc_state.rebuild_index().await;

        // Check search index initialization
        let idx = arc_state.search_index.read().unwrap();
        // Force reload reader to ensure it sees the commit made by rebuild_index
        idx.reader.reload().unwrap();
        println!(
            "Index reader doc count: {}",
            idx.reader.searcher().num_docs()
        );

        let all_docs = idx.search("Test", None).expect("Search failed");
        println!("All docs for 'Test': {:?}", all_docs);

        // Verify the task added synchronously is actually searchable
        let results = idx.search("Test", None).expect("Search failed");
        assert_eq!(results.len(), 1, "Expected exactly 1 search result");
        assert_eq!(
            results[0].0, "123",
            "Expected the result to be the task we just added"
        );
        assert_eq!(results[0].1, "task", "Expected document type to be task");
    }
}