-- name: GetTemplatePrebuildState :many
WITH
	-- All prebuilds currently running
	running_prebuilds AS (SELECT p.template_id,
								 b.template_version_id,
								 tvp_curr.id                 AS current_preset_id,
								 tvp_desired.id              AS desired_preset_id,
								 COUNT(*)                    AS count,
								 SUM(CASE
										 WHEN p.lifecycle_state = 'ready'::workspace_agent_lifecycle_state THEN 1
										 ELSE 0 END)         AS eligible,
								 STRING_AGG(p.id::text, ',') AS ids
						  FROM workspace_prebuilds p
								   INNER JOIN workspace_latest_build b ON b.workspace_id = p.id
								   INNER JOIN provisioner_jobs pj ON b.job_id = pj.id
								   INNER JOIN templates t ON p.template_id = t.id
								   LEFT JOIN template_version_presets tvp_curr
											 ON tvp_curr.id = b.template_version_preset_id
								   LEFT JOIN template_version_presets tvp_desired
											 ON tvp_desired.template_version_id = t.active_version_id
						  WHERE (b.transition = 'start'::workspace_transition
							  -- if a deletion job fails, the workspace will still be running
							  OR pj.job_status IN ('failed'::provisioner_job_status, 'canceled'::provisioner_job_status,
												   'unknown'::provisioner_job_status))
							AND (tvp_curr.name = tvp_desired.name
							  OR tvp_desired.id IS NULL)
						  GROUP BY p.template_id, b.template_version_id, tvp_curr.id,
								   tvp_desired.id),
	-- All templates which have been configured for prebuilds (any version)
	templates_with_prebuilds AS (SELECT t.id                        AS template_id,
										tv.id                       AS template_version_id,
										tv.id = t.active_version_id AS using_active_version,
										tvpp.preset_id,
										tvp.name,
										MAX(tvpp.desired_instances) AS desired_instances,
										t.deleted,
										t.deprecated != ''          AS deprecated
								 FROM templates t
										  INNER JOIN template_versions tv ON tv.template_id = t.id
										  INNER JOIN template_version_presets tvp ON tvp.template_version_id = tv.id
										  INNER JOIN template_version_preset_prebuilds tvpp ON tvpp.preset_id = tvp.id
								 WHERE t.id = @template_id::uuid
								 GROUP BY t.id, tv.id, tvpp.preset_id, tvp.name),
	-- Jobs relating to prebuilds current in-flight
	prebuilds_in_progress AS (SELECT wpb.template_version_id, wpb.transition, COUNT(wpb.transition) AS count
							  FROM workspace_latest_build wlb
									   INNER JOIN provisioner_jobs pj ON wlb.job_id = pj.id
									   INNER JOIN workspace_prebuild_builds wpb ON wpb.id = wlb.id
							  WHERE pj.job_status NOT IN
									('succeeded'::provisioner_job_status, 'canceled'::provisioner_job_status,
									 'failed'::provisioner_job_status)
							  GROUP BY wpb.template_version_id, wpb.transition)
SELECT t.template_id,
	   t.template_version_id,
	   t.preset_id,
	   t.using_active_version                                                         AS is_active,
	   MAX(CASE
			   WHEN p.template_version_id = t.template_version_id THEN p.ids
			   ELSE '' END)::text                                                     AS running_prebuild_ids,
	   COALESCE(MAX(CASE WHEN t.using_active_version THEN p.count ELSE 0 END),
				0)::int                                                               AS actual,     -- running prebuilds for active version
	   COALESCE(MAX(CASE WHEN t.using_active_version THEN p.eligible ELSE 0 END),
				0)::int                                                               AS eligible,   -- prebuilds which can be claimed
	   MAX(CASE WHEN t.using_active_version THEN t.desired_instances ELSE 0 END)::int AS desired,    -- we only care about the active version's desired instances
	   COALESCE(MAX(CASE
						WHEN p.template_version_id = t.template_version_id AND
							 t.using_active_version = false
							THEN p.count
						ELSE 0 END),
				0)::int                                                               AS outdated,   -- running prebuilds for inactive version
	   COALESCE(GREATEST(
					(MAX(CASE WHEN t.using_active_version THEN p.count ELSE 0 END)::int
						-
					 MAX(CASE WHEN t.using_active_version THEN t.desired_instances ELSE 0 END)),
					0),
				0) ::int                                                              AS extraneous, -- extra running prebuilds for active version
	   COALESCE(MAX(CASE
						WHEN pip.transition = 'start'::workspace_transition THEN pip.count
						ELSE 0 END),
				0)::int                                                               AS starting,
	   COALESCE(MAX(CASE
						WHEN pip.transition = 'stop'::workspace_transition THEN pip.count
						ELSE 0 END),
				0)::int                                                               AS stopping,   -- not strictly needed, since prebuilds should never be left if a "stopped" state, but useful to know
	   COALESCE(MAX(CASE
						WHEN pip.transition = 'delete'::workspace_transition THEN pip.count
						ELSE 0 END),
				0)::int                                                               AS deleting,
	   t.deleted::bool                                                                AS template_deleted,
	   t.deprecated::bool                                                             AS template_deprecated
FROM templates_with_prebuilds t
		 LEFT JOIN running_prebuilds p
				   ON (p.template_version_id = t.template_version_id AND p.current_preset_id = t.preset_id)
		 LEFT JOIN prebuilds_in_progress pip ON pip.template_version_id = t.template_version_id
WHERE (t.using_active_version = TRUE
	OR p.count > 0)
GROUP BY t.template_id, t.template_version_id, t.preset_id, t.using_active_version, t.deleted, t.deprecated;

-- name: ClaimPrebuild :one
-- TODO: rewrite to use named CTE instead?
UPDATE workspaces w
SET owner_id   = @new_user_id::uuid,
	name       = @new_name::text,
	updated_at = NOW()
WHERE w.id IN (SELECT p.id
			   FROM workspace_prebuilds p
						INNER JOIN workspace_latest_build b ON b.workspace_id = p.id
						INNER JOIN provisioner_jobs pj ON b.job_id = pj.id
						INNER JOIN templates t ON p.template_id = t.id
			   WHERE (b.transition = 'start'::workspace_transition
				   AND pj.job_status IN ('succeeded'::provisioner_job_status))
				 AND b.template_version_id = t.active_version_id
				 AND b.template_version_preset_id = @preset_id::uuid
				 AND p.lifecycle_state = 'ready'::workspace_agent_lifecycle_state
			   ORDER BY random()
			   LIMIT 1 FOR UPDATE OF p SKIP LOCKED)
RETURNING w.id, w.name;

-- name: InsertPresetPrebuild :one
INSERT INTO template_version_preset_prebuilds (id, preset_id, desired_instances, invalidate_after_secs)
VALUES (@id::uuid, @preset_id::uuid, @desired_instances::int, @invalidate_after_secs::int)
RETURNING *;