use crate::AppState;
use axum::extract::{Query, State};
use std::collections::HashMap;
use std::sync::Arc;

#[derive(serde::Deserialize, serde::Serialize, Debug, Clone, PartialEq)]
pub struct ProjectedTechDebt {
    pub id: String,
    pub description: String,
    pub severity: Option<String>,
    pub line_range: Option<String>,
    pub file_path: Option<String>,
    pub ideal_solution: String,
}

#[derive(serde::Deserialize, serde::Serialize, Debug, Clone, PartialEq)]
pub struct ProjectedAdr {
    pub id: String,
    pub title: String,
    pub decision: String,
    pub status: String,
    pub affected_components: Vec<String>,
}

pub fn find_projected_knowledge(
    state: &crate::state::MemoryState,
    file_path: &str,
) -> (Vec<ProjectedTechDebt>, Vec<ProjectedAdr>) {
    let normalized_file = file_path.replace('\\', "/").to_lowercase();
    
    // An empty file path matches everything due to `ends_with("")` behavior.
    // Return empty results immediately for [No Name] buffers.
    if normalized_file.trim().is_empty() {
        return (Vec::new(), Vec::new());
    }

    let file_name = std::path::Path::new(&normalized_file)
        .file_name()
        .and_then(|n| n.to_str())
        .unwrap_or("")
        .to_string();

    let debts = state.code.tech_debts.read_with(|all_debts| {
        all_debts
            .iter()
            .filter(|d| !d.is_resolved)
            .filter(|d| {
                if let Some(ref dfp) = d.file_path {
                    let ndfp = dfp.replace('\\', "/").to_lowercase();
                    if normalized_file == ndfp
                        || normalized_file.ends_with(&format!("/{}", ndfp.trim_start_matches('/')))
                        || ndfp.ends_with(&format!("/{}", normalized_file.trim_start_matches('/')))
                        || (!file_name.is_empty()
                            && (ndfp == file_name || ndfp.ends_with(&format!("/{}", file_name))))
                    {
                        return true;
                    }
                }
                if !file_name.is_empty()
                    && file_name.len() > 3
                    && d.description.to_lowercase().contains(&file_name)
                {
                    return true;
                }
                false
            })
            .map(|d| ProjectedTechDebt {
                id: d.id.clone(),
                description: d.description.clone(),
                severity: d.severity.clone(),
                line_range: d.line_range.clone(),
                file_path: d.file_path.clone(),
                ideal_solution: d.ideal_solution.clone(),
            })
            .collect()
    });

    let adrs = state.code.adrs.read_with(|all_adrs| {
        all_adrs
            .iter()
            .filter(|a| {
                a.status.eq_ignore_ascii_case("accepted") || a.status.eq_ignore_ascii_case("active")
            })
            .filter(|a| {
                for comp in &a.affected_components {
                    let ncomp = comp.replace('\\', "/").to_lowercase();
                    if !ncomp.is_empty()
                        && (normalized_file.ends_with(&ncomp)
                            || ncomp.ends_with(&normalized_file)
                            || (!file_name.is_empty() && ncomp.contains(&file_name)))
                    {
                        return true;
                    }
                }
                if !file_name.is_empty()
                    && file_name.len() > 3
                    && (a.title.to_lowercase().contains(&file_name)
                        || a.decision.to_lowercase().contains(&file_name))
                {
                    return true;
                }
                false
            })
            .map(|a| ProjectedAdr {
                id: a.id.clone(),
                title: a.title.clone(),
                decision: a.decision.clone(),
                status: a.status.clone(),
                affected_components: a.affected_components.clone(),
            })
            .collect()
    });

    (debts, adrs)
}

#[derive(serde::Deserialize, serde::Serialize, Debug)]
pub struct NvimTelemetry {
    pub session_id: String,
    pub event: String,
    pub file: Option<String>,
    pub line: Option<i64>,
    pub col: Option<i64>,
    // New interactive fields
    pub prompt: Option<String>,
    pub response: Option<String>,
    pub index: Option<i64>,
    pub request_id: Option<String>,
    pub diff_id: Option<String>,
    pub start_row: Option<i64>,
    pub end_row: Option<i64>,
}

pub async fn nvim_telemetry_handler(
    State(state): State<Arc<AppState>>,
    axum::Json(payload): axum::Json<NvimTelemetry>,
) -> impl axum::response::IntoResponse {
    // 1. Update active_nvim.txt if FocusGained, BufEnter, or VimEnter
    if payload.event == "FocusGained" || payload.event == "BufEnter" || payload.event == "VimEnter"
    {
        let session = &payload.session_id;
        let is_unix_socket = session.starts_with('/') || session.starts_with('~');

        if is_unix_socket {
            let wsl_path = "\\\\wsl.localhost\\Ubuntu\\home\\riz\\.gemini\\active_nvim.txt";
            let _ = tokio::fs::write(wsl_path, session).await;
        } else {
            let profile =
                std::env::var("USERPROFILE").unwrap_or_else(|_| "C:\\Users\\reazul.ashraf".into());
            let win_path = format!("{}\\.gemini\\active_nvim.txt", profile);
            let _ = tokio::fs::write(&win_path, session).await;
        }
    }

    // 2. Query Knowledge Graph for matching Tech Debts and ADRs (ADR-0103)
    let (tech_debts, adrs) = if let Some(ref f) = payload.file {
        find_projected_knowledge(&state.handler.state, f)
    } else {
        (Vec::new(), Vec::new())
    };

    // 3. Broadcast to UI WebSockets
    let ws_msg = serde_json::json!({
        "type": "nvim_telemetry",
        "data": payload,
        "tech_debts": tech_debts,
        "adrs": adrs
    });

    let msg_str = ws_msg.to_string();
    let senders: Vec<_> = state
        .clients
        .read()
        .unwrap_or_else(|e| e.into_inner())
        .values()
        .cloned()
        .collect();
    for tx in senders {
        let _ = tx.try_send(msg_str.clone());
    }

    if payload.event == "BufWritePost"
        && let Some(ref file_path) = payload.file
    {
        let normalized_file = file_path.replace("\\", "/");
        let topic = format!("nvim:save:{}", normalized_file);
        let event = crate::state::GenericEvent {
            topic,
            session_id: Some(payload.session_id.clone()),
            payload: serde_json::json!(&payload),
        };
        let _ = state.handler.state.event_bus_tx.send(event);
    }

    if payload.event.starts_with("agent_") || payload.event.starts_with("diff_") {
        let payload_val = serde_json::json!(&payload);
        let _ = state
            .handler
            .state
            .event_bus_tx
            .send(crate::state::GenericEvent {
                topic: format!("nvim:ui:{}", payload.event),
                session_id: Some(payload.session_id.clone()),
                payload: payload_val.clone(),
            });

        if let Some(ref req_id) = payload.request_id {
            let _ = state
                .handler
                .state
                .event_bus_tx
                .send(crate::state::GenericEvent {
                    topic: format!("nvim:ui:{}:{}", payload.event, req_id),
                    session_id: Some(payload.session_id.clone()),
                    payload: payload_val.clone(),
                });
        }

        if let Some(ref diff_id) = payload.diff_id {
            let _ = state
                .handler
                .state
                .event_bus_tx
                .send(crate::state::GenericEvent {
                    topic: format!("nvim:ui:{}:{}", payload.event, diff_id),
                    session_id: Some(payload.session_id.clone()),
                    payload: payload_val.clone(),
                });
            let _ = state
                .handler
                .state
                .event_bus_tx
                .send(crate::state::GenericEvent {
                    topic: format!("nvim:ui:diff_decision:{}", diff_id),
                    session_id: Some(payload.session_id.clone()),
                    payload: payload_val.clone(),
                });
        }
    }

    if let Some(ref f) = payload.file {
        state.handler.state.record_activity(
            "editor",
            &format!("Neovim {}: {}", payload.event, f),
            None,
        );
    }

    // 4. Extract active task & push gate for zero-polling statusline
    let active_task = state.handler.state.project.tasks.read_with(|tasks| {
        tasks
            .iter()
            .find(|t| t.is_active())
            .or_else(|| {
                tasks
                    .iter()
                    .find(|t| t.status == "pending" && t.parent_id.is_none())
            })
            .map(|t| t.title.clone())
    });

    let active_gate = state.handler.state.env.gates.read_with(|gates| {
        gates
            .iter()
            .find(|g| g.action == "push" || g.gate_type.as_deref() == Some("quality_gate"))
            .map(|g| g.status.clone())
    });

    axum::Json(serde_json::json!({
        "status": "ok",
        "tech_debts": tech_debts,
        "adrs": adrs,
        "active_task": active_task,
        "active_gate": active_gate
    }))
}

pub async fn nvim_knowledge_projection_handler(
    State(state): State<Arc<AppState>>,
    Query(params): Query<HashMap<String, String>>,
) -> impl axum::response::IntoResponse {
    let (tech_debts, adrs) = if let Some(file_path) = params.get("file") {
        find_projected_knowledge(&state.handler.state, file_path)
    } else {
        (Vec::new(), Vec::new())
    };

    axum::Json(serde_json::json!({
        "status": "ok",
        "tech_debts": tech_debts,
        "adrs": adrs
    }))
}

use crate::models::TerminalHistory;

pub async fn get_terminal_history_handler(
    State(state): State<Arc<AppState>>,
) -> impl axum::response::IntoResponse {
    let history_json = state
        .handler
        .state
        .telemetry
        .terminal_history
        .read_with(|h| serde_json::to_string(h).unwrap_or_else(|_| "[]".to_string()));
    (
        [(axum::http::header::CONTENT_TYPE, "application/json")],
        history_json,
    )
}

pub async fn terminal_telemetry_handler(
    State(state): State<Arc<AppState>>,
    axum::Json(payload): axum::Json<TerminalHistory>,
) -> impl axum::response::IntoResponse {
    state.handler.state.record_activity(
        "terminal",
        &format!("Ran command: {}", payload.command),
        Some(&format!(
            "exit_code: {}, cwd: {}",
            payload.exit_code, payload.cwd
        )),
    );

    state.handler.state.record_terminal_history(payload.clone());

    let ws_msg = serde_json::json!({
        "type": "terminal_telemetry",
        "data": payload
    });

    let msg_str = ws_msg.to_string();
    let senders: Vec<_> = state
        .clients
        .read()
        .unwrap_or_else(|e| e.into_inner())
        .values()
        .cloned()
        .collect();
    for tx in senders {
        let _ = tx.try_send(msg_str.clone());
    }

    axum::Json(serde_json::json!({"status": "ok"}))
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::router::MemoryHandler;
    use crate::state::MemoryState;
    use axum::http::Request;
    use axum::routing::get;
    use axum::routing::post;
    use std::collections::HashMap;
    use std::sync::atomic::AtomicUsize;
    use tempfile::tempdir;
    use tower::ServiceExt;

    #[tokio::test]
    async fn test_terminal_history() {
        let dir = tempdir().unwrap();
        let state = Arc::new(MemoryState::new(dir.path().to_str().unwrap()));
        let (shutdown_tx, _) = tokio::sync::oneshot::channel();
        let app_state = Arc::new(AppState {
            handler: Arc::new(MemoryHandler::new(state.clone())),
            clients: std::sync::RwLock::new(HashMap::new()),
            next_id: AtomicUsize::new(1),
            shutdown_tx: std::sync::Mutex::new(Some(shutdown_tx)),
        });

        let app = axum::Router::new()
            .route("/api/terminal/history", get(get_terminal_history_handler))
            .route("/terminal/telemetry", post(terminal_telemetry_handler))
            .with_state(app_state.clone());

        // Create a fake terminal telemetry payload
        let payload = TerminalHistory {
            command: "echo test".to_string(),
            exit_code: 0,
            cwd: "C:/Users/reazul.ashraf/workspace".to_string(),
            os: "windows".to_string(),
            timestamp: 12345,
            error_output: None,
            ..Default::default()
        };

        // Post the telemetry
        let req = Request::builder()
            .method("POST")
            .uri("/terminal/telemetry")
            .header("content-type", "application/json")
            .body(axum::body::Body::from(
                serde_json::to_string(&payload).unwrap(),
            ))
            .unwrap();

        let response = app.clone().oneshot(req).await.unwrap();
        assert_eq!(response.status(), 200);

        // Get the telemetry
        let req2 = Request::builder()
            .method("GET")
            .uri("/api/terminal/history")
            .body(axum::body::Body::empty())
            .unwrap();

        let response2 = app.oneshot(req2).await.unwrap();
        assert_eq!(response2.status(), 200);

        let body_bytes = axum::body::to_bytes(response2.into_body(), usize::MAX)
            .await
            .unwrap();
        let history: Vec<TerminalHistory> = serde_json::from_slice(&body_bytes).unwrap();
        assert_eq!(history.len(), 1);
        assert_eq!(history[0].command, "echo test");
    }

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

        // Add 1 unresolved Tech Debt for server/src/lib.rs
        state.code.tech_debts.modify(|debts| {
            debts.push(crate::models::TechDebt {
                id: "td-001".to_string(),
                namespace: "default".to_string(),
                description: "Refactor router dispatch in lib.rs".to_string(),
                ideal_solution: "Use modular sub-routers".to_string(),
                is_resolved: false,
                created_at: 1000,
                file_path: Some("server/src/lib.rs".to_string()),
                line_range: Some("100-150".to_string()),
                severity: Some("high".to_string()),
                ..Default::default()
            });
            // Add 1 resolved Tech Debt which should NOT be projected
            debts.push(crate::models::TechDebt {
                id: "td-002".to_string(),
                namespace: "default".to_string(),
                description: "Old resolved debt".to_string(),
                ideal_solution: "Done".to_string(),
                is_resolved: true,
                created_at: 500,
                file_path: Some("server/src/lib.rs".to_string()),
                ..Default::default()
            });
        });

        // Add 1 accepted ADR for server/src/lib.rs
        state.code.adrs.modify(|adrs| {
            adrs.push(crate::models::Adr {
                id: "ADR-0103".to_string(),
                title: "Virtual Text Knowledge Projection".to_string(),
                context: "Context".to_string(),
                decision: "Project tech debt and ADRs into active buffer".to_string(),
                consequence: "High developer awareness".to_string(),
                status: "accepted".to_string(),
                timestamp: 2000,
                affected_components: vec![
                    "server/src/lib.rs".to_string(),
                    "gemini-ui.lua".to_string(),
                ],
                ..Default::default()
            });
            // Add 1 superseded ADR which should NOT be projected
            adrs.push(crate::models::Adr {
                id: "ADR-0099".to_string(),
                title: "Old decision".to_string(),
                context: "Context".to_string(),
                decision: "Old".to_string(),
                consequence: "Old".to_string(),
                status: "superseded".to_string(),
                timestamp: 1000,
                affected_components: vec!["server/src/lib.rs".to_string()],
                ..Default::default()
            });
        });

        // Test with Windows path format
        let (debts, adrs) = find_projected_knowledge(
            &state,
            "C:\\Users\\reazul.ashraf\\workspace\\rust\\mcp-memory\\server\\src\\lib.rs",
        );
        assert_eq!(debts.len(), 1);
        assert_eq!(debts[0].id, "td-001");
        assert_eq!(debts[0].severity.as_deref(), Some("high"));
        assert_eq!(adrs.len(), 1);
        assert_eq!(adrs[0].id, "ADR-0103");

        // Test with unrelated file
        let (debts_unrelated, adrs_unrelated) =
            find_projected_knowledge(&state, "crates/unrelated/src/foo.rs");
        assert!(debts_unrelated.is_empty());
        assert!(adrs_unrelated.is_empty());
    }

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

        state.code.tech_debts.modify(|debts| {
            debts.push(crate::models::TechDebt {
                id: "td-active".to_string(),
                namespace: "default".to_string(),
                description: "Fix concurrency lock".to_string(),
                ideal_solution: "Use tokio rwlock".to_string(),
                is_resolved: false,
                created_at: 1000,
                file_path: Some("server/src/api/telemetry.rs".to_string()),
                line_range: Some("25".to_string()),
                severity: Some("medium".to_string()),
                ..Default::default()
            });
        });

        state.code.adrs.modify(|adrs| {
            adrs.push(crate::models::Adr {
                id: "ADR-0102".to_string(),
                title: "Neovim RPC Circuit Breaker".to_string(),
                context: "Context".to_string(),
                decision: "Fail fast".to_string(),
                consequence: "No hangs".to_string(),
                status: "accepted".to_string(),
                timestamp: 1000,
                affected_components: vec!["telemetry.rs".to_string()],
                ..Default::default()
            });
        });

        let (shutdown_tx, _) = tokio::sync::oneshot::channel();
        let app_state = Arc::new(AppState {
            handler: Arc::new(MemoryHandler::new(state.clone())),
            clients: std::sync::RwLock::new(HashMap::new()),
            next_id: AtomicUsize::new(1),
            shutdown_tx: std::sync::Mutex::new(Some(shutdown_tx)),
        });

        let app = axum::Router::new()
            .route("/nvim/telemetry", post(nvim_telemetry_handler))
            .route(
                "/api/nvim/projection",
                get(nvim_knowledge_projection_handler),
            )
            .with_state(app_state.clone());

        // 1. Post BufEnter telemetry
        let payload = NvimTelemetry {
            session_id: "test-session".to_string(),
            event: "BufEnter".to_string(),
            file: Some(
                "C:/Users/reazul.ashraf/workspace/rust/mcp-memory/server/src/api/telemetry.rs"
                    .to_string(),
            ),
            line: Some(25),
            col: Some(1),
            prompt: None,
            response: None,
            index: None,
            request_id: None,
            diff_id: None,
            start_row: None,
            end_row: None,
        };

        let req = Request::builder()
            .method("POST")
            .uri("/nvim/telemetry")
            .header("content-type", "application/json")
            .body(axum::body::Body::from(
                serde_json::to_string(&payload).unwrap(),
            ))
            .unwrap();

        let response = app.clone().oneshot(req).await.unwrap();
        assert_eq!(response.status(), 200);

        let body_bytes = axum::body::to_bytes(response.into_body(), usize::MAX)
            .await
            .unwrap();
        let body: serde_json::Value = serde_json::from_slice(&body_bytes).unwrap();
        assert_eq!(body["status"], "ok");
        assert_eq!(body["tech_debts"].as_array().unwrap().len(), 1);
        assert_eq!(body["tech_debts"][0]["id"], "td-active");
        assert_eq!(body["adrs"].as_array().unwrap().len(), 1);
        assert_eq!(body["adrs"][0]["id"], "ADR-0102");

        // 2. Query GET /api/nvim/projection
        let req2 = Request::builder()
            .method("GET")
            .uri("/api/nvim/projection?file=server/src/api/telemetry.rs")
            .body(axum::body::Body::empty())
            .unwrap();

        let response2 = app.oneshot(req2).await.unwrap();
        assert_eq!(response2.status(), 200);

        let body_bytes2 = axum::body::to_bytes(response2.into_body(), usize::MAX)
            .await
            .unwrap();
        let body2: serde_json::Value = serde_json::from_slice(&body_bytes2).unwrap();
        assert_eq!(body2["status"], "ok");
        assert_eq!(body2["tech_debts"].as_array().unwrap().len(), 1);
        assert_eq!(body2["adrs"].as_array().unwrap().len(), 1);
    }
}