//! The approval queue wire shape: one row (`Approval`) per pending/resolved
//! operator decision, its `kind` discriminator, and the terminal-state enum.
//! `ReminderStats` lives here too — small enough not to earn its own file,
//! and unrelated to any other topic module.

use chrono::{DateTime, Utc};
use hive_types::Ident;
use serde::{Deserialize, Serialize};

/// One row in the approval queue. `commit_ref` is overloaded per
/// `kind` — see `docs/approvals.md::Approval kinds (wire shapes)`
/// for the encoding table and lifecycle.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Approval {
    pub id: i64,
    pub agent: Ident,
    #[serde(default)]
    pub kind: ApprovalKind,
    /// Kind-specific payload (git sha / inputs array / schedule
    /// payload / empty). See the Approval struct doc.
    pub commit_ref: String,
    /// The canonical hive-c0re-vouched sha. For `MergeConfigPr`: the
    /// reviewed PR head pinned at submit; if the PR head drifts off it
    /// before merge, hive-c0re cancels the stale approval and re-queues a
    /// fresh one for re-review.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub fetched_sha: Option<String>,
    pub requested_at: DateTime<Utc>,
    pub status: ApprovalStatus,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub resolved_at: Option<DateTime<Utc>>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub note: Option<String>,
    /// Free-text description the manager attached at submission time;
    /// shown on the dashboard approval card.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
}

/// What action the approval, when granted, will trigger.
/// Variant-specific payload encoding +  flow lives in
/// `docs/approvals.md::Approval kinds (wire shapes)`.
#[derive(Debug, Clone, Copy, Default, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "snake_case")]
pub enum ApprovalKind {
    /// Create + start a new sub-agent container with the given name
    /// (under the default `agent.nix` template).
    Spawn,
    /// Create an agent's config repo and seed it from the default
    /// template (step 1 of the two-step spawn flow). Creating it is the
    /// whole of this step — tailoring what the template seeded is not a
    /// separate mechanism, it's a `MergeConfigPr` like every later
    /// change.
    InitConfig,
    /// Run `nix flake update [inputs...]` on the meta flake and commit
    /// the resulting lock changes.
    UpdateMetaInputs,
    /// Add a scheduled prompt to the broker queue.
    SchedulePrompt,
    /// Merge an operator-reviewed config PR: hive-c0re verifies the
    /// reviewed PR head, fast-forwards the forge config repo's `main`
    /// to it, marks the PR merged, then runs the deploy tail. This is the
    /// sole config-change flow — a manager opens a PR on its
    /// `agent-configs/<agent>` repo and the operator reviews + approves it.
    /// `commit_ref` = PR number; `fetched_sha` = the reviewed PR head
    /// pinned at submit. See `docs/approvals.md`.
    #[default]
    MergeConfigPr,
}

impl ApprovalKind {
    /// Wire/UI string — the same value serde's `snake_case` rename
    /// produces. The single source of truth for every place that needs
    /// the kind as a `&'static str` (sqlite storage, dashboard events),
    /// so adding a variant can't silently miss a hand-rolled match.
    #[must_use]
    pub fn as_str(self) -> &'static str {
        match self {
            ApprovalKind::Spawn => "spawn",
            ApprovalKind::InitConfig => "init_config",
            ApprovalKind::UpdateMetaInputs => "update_meta_inputs",
            ApprovalKind::SchedulePrompt => "schedule_prompt",
            ApprovalKind::MergeConfigPr => "merge_config_pr",
        }
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
#[serde(rename_all = "snake_case")]
pub enum ApprovalStatus {
    Pending,
    Approved,
    Denied,
    Failed,
    /// Manager withdrew the request before the operator acted on it.
    /// Distinct from `Denied` (operator decision) and `Failed`
    /// (post-approval lifecycle error). See
    /// `docs/approvals.md::Withdrawing a pending approval`.
    Cancelled,
}

/// Reminder activity statistics for an agent over a time window.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ReminderStats {
    /// Total reminders scheduled in the window (`created_at` >= cutoff).
    pub scheduled: u64,
    /// Reminders that have been delivered in the window (`sent_at` IS NOT NULL).
    pub delivered: u64,
    /// Reminders still pending in the window (`sent_at` IS NULL).
    pub pending: u64,
}