//! Scheduled-prompt request handlers (`ListSchedules` /
//! `RequestSchedulePrompt` / `CancelSchedule` / `EditSchedule` /
//! `FireScheduleNow`), their shared ownership check, and the
//! schedule-to-wire mapping reused by the dashboard
//! (`schedule_to_wire_public` / `filter_ghost_schedule_targets`).

use std::sync::Arc;

use hive_core_agent_sock::Response;

use crate::coordinator::Coordinator;

/// `ListSchedules` — snapshot every scheduled prompt onto the wire.
pub(super) fn handle_list_schedules(coord: &Arc<Coordinator>) -> Response {
    match coord.scheduled_prompts.list() {
        Ok(schedules) => Response::Schedules {
            schedules: schedules.into_iter().map(schedule_to_wire).collect(),
        },
        Err(e) => Response::Err {
            message: format!("list scheduled prompts: {e:#}"),
        },
    }
}

/// Submit a `RequestSchedulePrompt` payload as an `ApprovalKind::SchedulePrompt`
/// row. Encodes the payload into the approval's `commit_ref` so the
/// approve handler can re-parse it without a side table. Validates
/// inputs (non-empty targets, non-empty body, sane interval) at
/// submit time — the operator should never see a malformed schedule
/// pending approval.
pub(super) fn handle_request_schedule_prompt(
    coord: &Arc<Coordinator>,
    requester: &str,
    payload: &hive_sh4re::SchedulePromptPayload,
) -> Response {
    if payload.targets.is_empty() {
        return Response::Err {
            message: "schedule must have at least one target".into(),
        };
    }
    if payload.body.trim().is_empty() {
        return Response::Err {
            message: "schedule body must be non-empty".into(),
        };
    }
    if let Some(0) = payload.interval_seconds {
        return Response::Err {
            message: "interval_seconds must be > 0 (use None for one-shot)".into(),
        };
    }
    let commit_ref = match serde_json::to_string(payload) {
        Ok(s) => s,
        Err(e) => {
            return Response::Err {
                message: format!("encode SchedulePromptPayload: {e:#}"),
            };
        }
    };
    let id = match coord.approvals.submit_kind(
        requester,
        hive_sh4re::ApprovalKind::SchedulePrompt,
        &commit_ref,
        payload.description.as_deref(),
        requester,
        None,
    ) {
        Ok(id) => id,
        Err(e) => {
            return Response::Err {
                message: format!("queue schedule_prompt approval: {e:#}"),
            };
        }
    };
    tracing::info!(
        %id,
        requester,
        targets = ?payload.targets,
        first_fire_at = payload.first_fire_at_unix,
        interval = ?payload.interval_seconds,
        "schedule_prompt approval queued"
    );
    coord.emit_approval_added(crate::coordinator::ApprovalAdded {
        id,
        agent: requester,
        approval_kind: "schedule_prompt",
        sha_short: None,
        description: payload.description.clone(),
        pr_number: None,
    });
    Response::Ok
}

/// Cancel a schedule (whole or per-target). Manager-surface
/// authorization: a manager can cancel its own schedules + any
/// schedule whose owner is one of its sub-agents (topology-walked).
/// The operator surface bypasses this and can cancel anything;
/// agents reaching this path through the manager get the
/// topology-scoped check.
pub(super) fn handle_cancel_schedule(
    coord: &Arc<Coordinator>,
    requester: &str,
    schedule_id: i64,
    targets: Option<&[String]>,
) -> Response {
    let schedule = match coord.scheduled_prompts.get(schedule_id) {
        Ok(Some(s)) => s,
        Ok(None) => {
            return Response::Err {
                message: format!("schedule {schedule_id} not found"),
            };
        }
        Err(e) => {
            return Response::Err {
                message: format!("read schedule {schedule_id}: {e:#}"),
            };
        }
    };
    if !cancel_authorized(requester, &schedule.owner) {
        return Response::Err {
            message: format!(
                "not authorized: {requester} cannot cancel schedule owned by {owner}",
                owner = schedule.owner
            ),
        };
    }
    let result = match targets {
        Some(list) if !list.is_empty() => coord
            .scheduled_prompts
            .cancel_targets(schedule_id, list)
            .map_err(|e| format!("cancel targets: {e:#}")),
        _ => coord
            .scheduled_prompts
            .cancel_all(schedule_id)
            .map_err(|e| format!("cancel all: {e:#}")),
    };
    match result {
        Ok(()) => {
            coord.emit_schedules_snapshot();
            Response::Ok
        }
        Err(message) => Response::Err { message },
    }
}

/// Authorize + dispatch a `FireScheduleNow` request from the
/// manager surface. Same ownership rules as `CancelSchedule`:
/// requester can fire its own schedules + any owned by an agent
/// in its subtree. The actual fan-out lives in
/// `scheduled_prompts_worker::fire_now`.
pub(super) async fn handle_fire_schedule_now(
    coord: &Arc<Coordinator>,
    requester: &str,
    schedule_id: i64,
) -> Response {
    let schedule = match coord.scheduled_prompts.get(schedule_id) {
        Ok(Some(s)) => s,
        Ok(None) => {
            return Response::Err {
                message: format!("schedule {schedule_id} not found"),
            };
        }
        Err(e) => {
            return Response::Err {
                message: format!("read schedule {schedule_id}: {e:#}"),
            };
        }
    };
    if !cancel_authorized(requester, &schedule.owner) {
        return Response::Err {
            message: format!(
                "not authorized: {requester} cannot fire schedule owned by {owner}",
                owner = schedule.owner
            ),
        };
    }
    // MCP fire_schedule_now stays no-reset (cadence intact); the
    // reset-timer option is a dashboard-dialog affordance.
    match crate::scheduled_prompts_worker::fire_now(coord, schedule_id, false).await {
        Ok(_report) => {
            coord.emit_schedules_snapshot();
            Response::Ok
        }
        Err(e) => Response::Err {
            message: format!("fire schedule {schedule_id} now: {e:#}"),
        },
    }
}

/// Field-named PATCH payload for [`handle_edit_schedule`]. Every
/// field is "leave alone" when `None`; the double-`Option` fields
/// additionally distinguish clear (`Some(None)`) from set
/// (`Some(Some(v))`).
#[allow(
    clippy::option_option,
    reason = "double-Option carries three-state PATCH semantics: outer None = \
              leave alone, Some(None) = clear, Some(Some(v)) = set"
)]
pub(super) struct EditSchedulePatch {
    pub(super) body: Option<String>,
    pub(super) description: Option<Option<String>>,
    pub(super) interval_seconds: Option<Option<u64>>,
    pub(super) next_fire_at_unix: Option<i64>,
    pub(super) targets_add: Option<Vec<String>>,
    pub(super) targets_remove: Option<Vec<String>>,
}

/// Authorize + dispatch a `EditSchedule` patch. Same ownership
/// rules as `CancelSchedule` — the manager can edit
/// schedules it owns + any owned by an agent in its subtree.
/// Forwards the partial payload to
/// `ScheduledPrompts::update` which enforces the cancelled-row /
/// zero-interval validation. Returns `Ok` on a clean update;
/// `Err` with the underlying message on any auth / validation
/// failure so the dashboard can surface it verbatim.
pub(super) fn handle_edit_schedule(
    coord: &Arc<Coordinator>,
    requester: &str,
    schedule_id: i64,
    patch: EditSchedulePatch,
) -> Response {
    let EditSchedulePatch {
        body,
        description,
        interval_seconds,
        next_fire_at_unix,
        targets_add,
        targets_remove,
    } = patch;
    let schedule = match coord.scheduled_prompts.get(schedule_id) {
        Ok(Some(s)) => s,
        Ok(None) => {
            return Response::Err {
                message: format!("schedule {schedule_id} not found"),
            };
        }
        Err(e) => {
            return Response::Err {
                message: format!("read schedule {schedule_id}: {e:#}"),
            };
        }
    };
    if !cancel_authorized(requester, &schedule.owner) {
        return Response::Err {
            message: format!(
                "not authorized: {requester} cannot edit schedule owned by {owner}",
                owner = schedule.owner
            ),
        };
    }
    let patch = crate::scheduled_prompts::UpdateSchedule {
        body,
        description,
        interval_seconds,
        next_fire_at_unix,
        targets_add,
        targets_remove,
    };
    match coord.scheduled_prompts.update(schedule_id, patch) {
        Ok(()) => {
            coord.emit_schedules_snapshot();
            Response::Ok
        }
        Err(e) => Response::Err {
            message: format!("edit schedule {schedule_id}: {e:#}"),
        },
    }
}

/// Permission check for `CancelSchedule` on the manager surface.
/// `requester` (always `ruth` here) can cancel its own schedules.
/// Sub-agent ownership is delegated to topology — see
/// `crate::topology::is_descendant_of`. Also reused by
/// `handle_fire_schedule_now` — fire-auth follows the same shape.
fn cancel_authorized(requester: &str, owner: &str) -> bool {
    if requester == owner {
        return true;
    }
    if requester == hive_sh4re::OPERATOR_RECIPIENT {
        return true;
    }
    // Manager can cancel anything owned by an agent in its subtree.
    // For the current single-manager topology that covers everything,
    // but the check stays correct as the tree grows.
    crate::topology::is_descendant_of(owner, requester)
}

/// Map a `scheduled_prompts::Schedule` to its public wire shape.
/// Field-by-field copy — the two types are intentionally identical;
/// the separation keeps hive-sh4re free of hive-c0re-internal types.
/// Public alias `schedule_to_wire_public` re-exports for
/// `dashboard.rs::api_schedules` without crossing the module
/// boundary into the socket-server file.
pub fn schedule_to_wire_public(s: crate::scheduled_prompts::Schedule) -> hive_sh4re::WireSchedule {
    schedule_to_wire(s)
}

/// Drop schedule targets that point at agents which no longer exist, so
/// the dashboard's schedule table doesn't render ghost columns for
/// destroyed agents. `live` is the set of logical agent names from the
/// last `nixos-container list` scan (stopped agents included, destroyed
/// ones absent); the `operator` pseudo-target is always retained since
/// it isn't a container. Applied only to the dashboard wire paths
/// (`api_schedules` + the `SchedulesChanged` SSE emit) — the
/// manager-facing `list_schedules` stays unfiltered so agents can still
/// see and cancel stale targets. This is a view filter: the underlying
/// schedule rows keep every target, so a re-spawned agent's targets
/// reappear on their own.
pub(crate) fn filter_ghost_schedule_targets(
    schedules: &mut [hive_sh4re::WireSchedule],
    live: &std::collections::HashSet<String>,
) {
    for s in schedules.iter_mut() {
        s.targets
            .retain(|t| t.target == hive_sh4re::OPERATOR_RECIPIENT || live.contains(&t.target));
    }
}

fn schedule_to_wire(s: crate::scheduled_prompts::Schedule) -> hive_sh4re::WireSchedule {
    hive_sh4re::WireSchedule {
        id: s.id,
        owner: s.owner,
        body: s.body,
        interval_seconds: s.interval_seconds,
        next_fire_at_unix: s.next_fire_at_unix,
        created_at_unix: s.created_at_unix,
        source: match s.source {
            crate::scheduled_prompts::ScheduleSource::Operator => {
                hive_sh4re::WireScheduleSource::Operator
            }
            crate::scheduled_prompts::ScheduleSource::Approval { id } => {
                hive_sh4re::WireScheduleSource::Approval { id }
            }
        },
        cancelled_at_unix: s.cancelled_at_unix,
        paused_at_unix: s.paused_at_unix,
        description: s.description,
        targets: s
            .targets
            .into_iter()
            .map(|t| hive_sh4re::WireScheduleTarget {
                target: t.target,
                cancelled_at_unix: t.cancelled_at_unix,
                last_fired_at_unix: t.last_fired_at_unix,
                last_result: t.last_result,
            })
            .collect(),
    }
}

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

    fn target(name: &str) -> hive_sh4re::WireScheduleTarget {
        hive_sh4re::WireScheduleTarget {
            target: name.to_owned(),
            cancelled_at_unix: None,
            last_fired_at_unix: None,
            last_result: None,
        }
    }

    fn schedule(targets: &[&str]) -> hive_sh4re::WireSchedule {
        hive_sh4re::WireSchedule {
            id: 1,
            owner: "operator".to_owned(),
            body: "ping".to_owned(),
            interval_seconds: None,
            next_fire_at_unix: hive_sh4re::wire_time::from_secs(0),
            created_at_unix: hive_sh4re::wire_time::from_secs(0),
            source: hive_sh4re::WireScheduleSource::Operator,
            cancelled_at_unix: None,
            paused_at_unix: None,
            description: None,
            targets: targets.iter().map(|t| target(t)).collect(),
        }
    }

    #[test]
    fn ghost_filter_drops_dead_agents_keeps_live_and_operator() {
        let live: std::collections::HashSet<String> = ["iris".to_owned(), "damocles".to_owned()]
            .into_iter()
            .collect();
        let mut schedules = vec![schedule(&["iris", "ghost", "operator", "damocles"])];
        filter_ghost_schedule_targets(&mut schedules, &live);
        let kept: Vec<&str> = schedules[0]
            .targets
            .iter()
            .map(|t| t.target.as_str())
            .collect();
        // `ghost` (destroyed) dropped; live agents + operator pseudo-target kept.
        assert_eq!(kept, vec!["iris", "operator", "damocles"]);
    }

    #[test]
    fn ghost_filter_can_empty_targets_when_all_dead() {
        let live: std::collections::HashSet<String> = std::collections::HashSet::new();
        let mut schedules = vec![schedule(&["gone1", "gone2"])];
        filter_ghost_schedule_targets(&mut schedules, &live);
        // operator is never in the live set but is always retained; here
        // there's no operator target, so everything drops.
        assert!(schedules[0].targets.is_empty());
    }
}