using Invercargill;
using Invercargill.DataStructures;
using Invercargill.Expressions;
using Spry;
using Spry.Authentication;
using Statum;
using ClankerSaddle.Data;
using ClankerSaddle.Services;

namespace ClankerSaddle {

    /** "3m ago"-style compact duration for the health panel. */
    private static string relative_time(int64 delta_ms) {
        int64 seconds = delta_ms.clamp(0, int64.MAX) / 1000;
        if (seconds < 60) {
            return @"$(seconds)s";
        }
        if (seconds < 3600) {
            return @"$(seconds / 60)m";
        }
        return @"$(seconds / 3600)h";
    }

    /** A capability chip on a saddle card, with its remove action. */
    public class SaddleCapabilityView : Object {
        public int64 link_id { get; set; }
        public string name { get; set; default = ""; }
        public Statum.Model.ActionDto? detach { get; set; }
    }

    /** A saddle card on the management page, with its current task and API token. */
    public class SaddleRowView : Object {
        public int64 id { get; set; }
        public string name { get; set; default = ""; }
        public string host { get; set; default = ""; }
        public string status { get; set; default = ""; }
        public string health { get; set; default = "unknown"; }
        public string daemon_state { get; set; default = ""; }
        public string uptime_display { get; set; default = ""; }
        public string last_contact_display { get; set; default = ""; }
        public string git_name { get; set; default = ""; }
        public string git_email { get; set; default = ""; }
        public string ssh_public_key { get; set; default = ""; }
        public Statum.Model.ActionDto? update_identity { get; set; }
        public int64 current_task_id { get; set; }
        public string current_task_title { get; set; default = ""; }
        /** Set when the current task is a goal agent's run: link the goal instead. */
        public int64 current_goal_id { get; set; }
        public string current_goal_title { get; set; default = ""; }
        public string allocated_display { get; set; default = ""; }
        public string token { get; set; default = ""; }
        public Statum.Model.ActionDto? unregister { get; set; }
        public Statum.Model.ActionDto? refresh { get; set; }
        public Statum.Model.ActionDto? attach_capability { get; set; }
    }

    /** A capability row in the saddles page's capabilities section. */
    public class CapabilityRowView : Object {
        public int64 id { get; set; }
        public string name { get; set; default = ""; }
        public int64 saddle_count { get; set; }
        public int64 task_count { get; set; }
        public Statum.Model.ActionDto? delete { get; set; }
    }

    /** An option in the attach selects (saddle cards and the task page). */
    public class CapabilityOptionView : Object {
        public int64 id { get; set; }
        public string name { get; set; default = ""; }
    }

    /** Public data of the `saddles` slot. */
    public class SaddlesPublic : Object {
        /** True when the viewer may see the admin controls (the actions
         * re-check the permission; this only shapes the page). */
        public bool is_admin { get; set; }
        public Statum.Model.ActionDto register { get; set; }
        public Statum.Model.ActionDto create_capability { get; set; }
    }

    /**
     * Entrypoint for /saddles: the saddle inventory plus the capability
     * tag catalogue. Admin-only (the authoritative guard); each card
     * carries its current task, capability chips (with remove actions),
     * the attach-capability select, and the unregister/refresh actions.
     */
    public class SaddlesEntrypoint : StatumEntrypoint {

        private SaddleService saddle_service = Inversion.inject<SaddleService>();
        private SaddlePollState poll_state = Inversion.inject<SaddlePollState>();
        private CapabilityService capability_service = Inversion.inject<CapabilityService>();
        private InvercargillSql.Orm.OrmSession db = Inversion.inject<InvercargillSql.Orm.OrmSession>();
        private UserService users = Inversion.inject<UserService>();

        public override async DirectiveBuilder handle() throws GLib.Error {
            // Viewing is open to every logged-in user (the roles
            // decision); the page's controls are admin-only, so the
            // public slot carries the admin flag the template's stm-if
            // guards bind against. The actions themselves enforce the
            // permission server-side.
            var guard = yield SpryAuth.require_login(directives(), request, users);
            if (guard != null) {
                return (!)guard;
            }
            bool is_admin = SpryAuth.current(request).has_permission(SpryAuth.ADMIN_PERMISSION);

            var capabilities = yield capability_service.list_capabilities();
            var capability_names = new Dictionary<string, string>();
            foreach (var capability in capabilities) {
                capability_names.set(capability.id.to_string(), capability.name);
            }
            var saddle_links = yield capability_service.all_saddle_attachments();
            var task_links = yield capability_service.all_task_attachments();

            var options = new Vector<CapabilityOptionView>();
            foreach (var capability in capabilities) {
                options.add(new CapabilityOptionView() {
                    id = capability.id,
                    name = capability.name
                });
            }

            // Per-saddle chips keyed by saddle id, attached to the row
            // models via list_rich below (slot lists cannot nest).
            var chips_by_saddle = new Dictionary<string, Vector<SaddleCapabilityView>>();
            foreach (var link in saddle_links) {
                string name = capability_names.get_or_default(link.capability_id.to_string()) ?? "?";
                var sealed_link = new SaddleCapabilityActionPrivate() {
                    saddle_id = link.saddle_id,
                    link_id = link.id
                };
                var chips = chips_by_saddle.get_or_default(link.saddle_id.to_string());
                if (chips == null) {
                    chips = new Vector<SaddleCapabilityView>();
                    chips_by_saddle.set(link.saddle_id.to_string(), chips);
                }
                ((!)chips).add(new SaddleCapabilityView() {
                    link_id = link.id,
                    name = name,
                    detach = action_registry.author_private<DetachSaddleCapabilityAction, SaddleCapabilityActionPrivate>(sealed_link)
                });
            }

            var rows = new Vector<SaddleRowView>();
            int64 now_ms = get_monotonic_time() / 1000;
            foreach (var saddle in yield saddle_service.list_saddles()) {
                string daemon_state = "";
                int64 uptime = 0;
                int64 activity = 0;
                int64 contact_ms = 0;
                poll_state.health_for(saddle.id, out daemon_state, out uptime,
                    out activity, out contact_ms);
                string health = "unknown";
                if (saddle.status == SADDLE_OFFLINE) {
                    health = "offline";
                } else if (daemon_state.length > 0) {
                    health = "healthy";
                    if (daemon_state == "working" && activity > 0
                            && now_ms / 1000 - activity
                                >= SaddleService.stale_after_seconds()) {
                        health = "stale";
                    }
                }
                string last_contact = contact_ms > 0
                    ? relative_time(now_ms - contact_ms) : "never";
                var sealed = new SaddleActionPrivate() { saddle_id = saddle.id };
                // Plan 16 item 23: the row reads the DERIVED view —
                // busy iff a running session exists (its started_at is
                // the allocation stamp), else the stored OFFLINE probe
                // state.
                var work = yield saddle_service.current_work_view(saddle);
                var view = new SaddleRowView() {
                    id = saddle.id,
                    name = saddle.name,
                    host = saddle.host,
                    status = SaddleService.derived_status(saddle, work),
                    health = health,
                    daemon_state = daemon_state,
                    uptime_display = uptime > 0 ? relative_time(uptime * 1000) : "",
                    last_contact_display = last_contact,
                    git_name = saddle.git_name ?? "",
                    git_email = saddle.git_email ?? "",
                    ssh_public_key = saddle.ssh_public_key ?? "",
                    update_identity = action_registry.author_private<UpdateSaddleIdentityAction, SaddleActionPrivate>(sealed),
                    current_task_id = work != null ? ((!)work).task_id : 0,
                    allocated_display = work != null
                        ? format_stamp(((!)work).started_at) : "",
                    unregister = action_registry.author_private<UnregisterSaddleAction, SaddleActionPrivate>(sealed),
                    refresh = action_registry.author_private<RefreshSaddleStatusAction, SaddleActionPrivate>(sealed),
                    attach_capability = action_registry.author_private<AttachSaddleCapabilityAction, SaddleActionPrivate>(sealed)
                };
                view.token = saddle.token ?? "";
                if (work != null) {
                    view.current_task_title = ((!)work).task_title;
                    if (((!)work).goal_id > 0) {
                        view.current_goal_id = ((!)work).goal_id;
                        view.current_goal_title = ((!)work).goal_title;
                    }
                }
                rows.add(view);
            }

            var capability_rows = new Vector<CapabilityRowView>();
            foreach (var capability in capabilities) {
                int64 saddle_count = 0;
                foreach (var link in saddle_links) {
                    if (link.capability_id == capability.id) {
                        saddle_count++;
                    }
                }
                int64 task_count = 0;
                foreach (var link in task_links) {
                    if (link.capability_id == capability.id) {
                        task_count++;
                    }
                }
                var sealed_capability = new CapabilityActionPrivate() { capability_id = capability.id };
                capability_rows.add(new CapabilityRowView() {
                    id = capability.id,
                    name = capability.name,
                    saddle_count = saddle_count,
                    task_count = task_count,
                    delete = action_registry.author_private<DeleteCapabilityAction, CapabilityActionPrivate>(sealed_capability)
                });
            }

            var pub = new SaddlesPublic();
            pub.is_admin = is_admin;
            pub.register = action_registry.author<RegisterSaddleAction>();
            pub.create_capability = action_registry.author<CreateCapabilityAction>();

            var props = (PropertyDictionary) GObjectMapping.to_properties(pub);
            props["saddles"] = StateJson.list_rich<SaddleRowView>(rows.to_immutable_buffer(),
                (item, dict) => {
                    var chips = chips_by_saddle.get_or_default(((SaddleRowView) item).id.to_string());
                    dict["capabilities"] = chips != null
                        ? StateJson.list<SaddleCapabilityView>(((!)chips).to_immutable_buffer())
                        : StateJson.list<SaddleCapabilityView>(
                            new Vector<SaddleCapabilityView>().to_immutable_buffer());
                });
            props["capabilities"] = StateJson.list<CapabilityRowView>(capability_rows.to_immutable_buffer());
            props["capability_options"] = StateJson.list<CapabilityOptionView>(options.to_immutable_buffer());

            var slot = state_service.new_slot(Scope.PAGE, new State() {
                type_name = "saddles",
                public_data = props,
                private_data = new PropertyDictionary()
            });
            return directives().set(slot);
        }
    }
}