package mysql

import (
	"context"
	"database/sql"
	"errors"

	core "git.yuntuo.hk/k2safe/orbit/model"
	"git.yuntuo.hk/k2safe/orbit/weave/engine"
)

type workflowTaskLink struct {
	Owner      sql.NullString
	Activation *core.ID
	Gate       *core.ID
	Linked     bool
}

// appendWorkflowResult 在原Pulse结果事务内创建内部交付，必须先于外部结果流行锁。
// 这里只核验稳定归属并写入队列，不锁实例/激活、不推进流程、不锁对外订阅。
func appendWorkflowResult(ctx context.Context, tx *sql.Tx, ns, eventID, taskID core.ID, revision uint64, snapshot []byte, link workflowTaskLink) error {
	owner, ownerID, gate := link.Owner, link.Activation, link.Gate
	if !owner.Valid || owner.String != engine.TaskOwnerKind {
		if owner.Valid && owner.String != "schedule" {
			return errors.New("unrecognized task owner")
		}
		// 无外键情况下，丢失owner不能把已有流程关联静默降级成普通任务。
		if link.Linked {
			return errors.New("workflow result ownership missing")
		}
		return nil
	}
	if ownerID == nil || gate == nil {
		return errors.New("workflow result owner or gate missing")
	}
	var workflow core.ID
	var kind string
	var activationTask *core.ID
	// 即使旧激活不再是current，也要保存内部事件，消费方再核对当前激活并留痕。
	err := tx.QueryRowContext(ctx, `SELECT a.workflow_id,s.kind,a.task_id
 FROM weave_activations a
 JOIN weave_steps s ON s.namespace_id=a.namespace_id AND s.id=a.step_id AND s.workflow_id=a.workflow_id
 JOIN weave_instances i ON i.namespace_id=a.namespace_id AND i.id=a.workflow_id AND i.gate_id=?
 JOIN pulse_execution_gates g ON g.namespace_id=i.namespace_id AND g.id=i.gate_id
 JOIN weave_definition_versions v ON v.namespace_id=i.namespace_id AND v.id=i.definition_version_id AND v.definition_id=i.definition_id
 JOIN weave_definitions d ON d.namespace_id=i.namespace_id AND d.id=i.definition_id
 WHERE a.namespace_id=? AND a.id=?`, gate, ns, ownerID).Scan(&workflow, &kind, &activationTask)
	if errors.Is(err, sql.ErrNoRows) {
		return errors.New("workflow result associations invalid")
	}
	if err != nil {
		return err
	}
	switch kind {
	case "TASK":
		if activationTask == nil || *activationTask != taskID {
			return errors.New("workflow activation task mismatch")
		}
	case "POLL":
		if activationTask != nil {
			return errors.New("poll activation cannot own a direct task")
		}
		var round uint32
		err = tx.QueryRowContext(ctx, `SELECT r.round FROM weave_poll_rounds r JOIN weave_poll_states p ON p.namespace_id=r.namespace_id AND p.workflow_id=r.workflow_id AND p.activation_id=r.activation_id WHERE r.namespace_id=? AND r.workflow_id=? AND r.activation_id=? AND r.task_id=? AND r.round BETWEEN p.first_round AND p.used_rounds`, ns, workflow, ownerID, taskID).Scan(&round)
		if errors.Is(err, sql.ErrNoRows) {
			return errors.New("workflow poll task association invalid")
		}
		if err != nil {
			return err
		}
	default:
		return errors.New("workflow task owner kind invalid")
	}
	id, err := core.NewID()
	if err != nil {
		return err
	}
	_, err = tx.ExecContext(ctx, `INSERT INTO weave_inbox(namespace_id,id,workflow_id,event_id,available_at,source_task_id,source_activation_id,source_revision,snapshot) VALUES (?,?,?,?,UTC_TIMESTAMP(6),?,?,?,?)`, ns, id, workflow, eventID, taskID, ownerID, revision, string(snapshot))
	return err
}