commit 6233590bb44556aceb8826474d7064760d464c67
Author: David J. Allen <davidallendj@gmail.com>
Date:   Sun Nov 17 13:47:37 2024 -0700

    add initial files

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..1c5bc07
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,11 @@
+module github.com/davidallendj/partitions
+
+go 1.23.3
+
+require github.com/rs/zerolog v1.33.0
+
+require (
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.19 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..98afda4
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,15 @@
+github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
+github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
+github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
+github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
+github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
diff --git a/internal/groups/groups.go b/internal/groups/groups.go
new file mode 100644
index 0000000..151db11
--- /dev/null
+++ b/internal/groups/groups.go
@@ -0,0 +1,39 @@
+package groups
+
+import (
+	"slices"
+
+	"github.com/davidallendj/partitions/internal/partitions"
+)
+
+type Group struct {
+	Name   string
+	Labels []string
+}
+
+func (g *Group) GetNodeIDs(pm *partitions.DefaultManager) []string {
+	foundNodes := []string{}
+	for _, label := range g.Labels {
+		nodeID := pm.LookupMember(label)
+		if nodeID != nil {
+			// check and make sure we're not duplicating node IDs
+			if !slices.Contains(foundNodes, *nodeID) {
+				foundNodes = append(foundNodes, *nodeID)
+			}
+		}
+	}
+	return foundNodes
+}
+
+func (g *Group) GetPartitions(pm *partitions.DefaultManager) []string {
+	foundPartitions := []string{}
+	for _, label := range g.Labels {
+		partition := pm.LookupPartitionByMemberID(label)
+		if partition != nil {
+			if !slices.Contains(foundPartitions, partition.ID) {
+				foundPartitions = append(foundPartitions, partition.ID)
+			}
+		}
+	}
+	return foundPartitions
+}
diff --git a/internal/nodes/nodes.go b/internal/nodes/nodes.go
new file mode 100644
index 0000000..3b48264
--- /dev/null
+++ b/internal/nodes/nodes.go
@@ -0,0 +1,11 @@
+package nodes
+
+import "errors"
+
+var (
+	ErrExists = errors.New("node exists")
+)
+
+type Node struct {
+	ID string
+}
diff --git a/internal/partitions/manager.go b/internal/partitions/manager.go
new file mode 100644
index 0000000..d6b928a
--- /dev/null
+++ b/internal/partitions/manager.go
@@ -0,0 +1,149 @@
+package partitions
+
+import (
+	"errors"
+	"fmt"
+	"slices"
+
+	"github.com/davidallendj/partitions/internal/nodes"
+)
+
+var (
+	ErrExists   = errors.New("partition exists")
+	ErrNotFound = errors.New("partition not found")
+)
+
+type Manager[T comparable] struct {
+	partitions []partition[T]
+}
+
+func (m *Manager[T]) CreatePartition(id string, members []T) error {
+	// todo: deduplicate node ids
+
+	// check if the partition already exists and fail if it does
+	if m.ContainsPartition(id) {
+		return ErrExists
+	}
+
+	// check the manager to see if there a nodes being added to multiple partitions
+	for _, member := range members {
+		if m.ContainsMember(member) {
+			return fmt.Errorf("%v: %v", nodes.ErrExists, member)
+		}
+	}
+
+	// no other issues at this point, so add the partition with nodes
+	m.partitions = append(m.partitions, partition[T]{ID: id, Members: members})
+	return nil
+}
+
+func (m *Manager[T]) AddNodeToPartition(partitionID string, member T) error {
+	// do lookup to find existing partition
+	partition := m.LookupPartitionByID(partitionID)
+	if partition != nil {
+		// check if node already exists and fail if it does
+		if m.ContainsMember(member) {
+			return fmt.Errorf("%v: %v", nodes.ErrExists, member)
+		}
+	} else {
+		// no partition found, so return error
+		return ErrNotFound
+	}
+	// add member to partition and update manager
+	partition.Members = append(partition.Members, member)
+	return nil
+}
+
+func (m *Manager[T]) LookupPartitionByID(id string) *partition[T] {
+	// try and get index of partition with ID
+	index := slices.IndexFunc(m.partitions, func(p partition[T]) bool {
+		return p.ID == id
+	})
+	// found a partition, so return it
+	if index >= 0 {
+		return &m.partitions[index]
+	}
+	return nil
+}
+
+func (m *Manager[T]) LookupPartitionByMemberID(member T) *partition[T] {
+	partitionIndex, _ := m.lookupMember(member)
+	if partitionIndex >= 0 {
+		return &m.partitions[partitionIndex]
+	}
+	return nil
+}
+
+func (m *Manager[T]) LookupMember(member T) *T {
+	var (
+		partitionIndex int
+		memberIndex    int
+	)
+	partitionIndex, memberIndex = m.lookupMember(member)
+	return m.getNodeFromPartition(partitionIndex, memberIndex)
+}
+
+func (m *Manager[T]) ContainsPartition(id string) bool {
+	return m.LookupPartitionByID(id) != nil
+}
+
+func (m *Manager[T]) ContainsMember(member T) bool {
+	var (
+		partitionIndex int
+		memberIndex    int
+	)
+
+	partitionIndex, memberIndex = m.lookupMember(member)
+	return partitionIndex >= 0 && memberIndex >= 0
+}
+
+func (m *Manager[T]) GetPartitions() []partition[T] {
+	return m.partitions
+}
+
+func (m *Manager[T]) GetPartitionIDs() []string {
+	partitionIDs := []string{}
+	for _, partition := range m.partitions {
+		partitionIDs = append(partitionIDs, partition.ID)
+	}
+	return partitionIDs
+}
+
+func (m *Manager[T]) GetPartitionMembers() []T {
+	members := []T{}
+	for _, partition := range m.partitions {
+		members = append(members, partition.Members...)
+	}
+	return members
+}
+
+func (m *Manager[T]) getNodeFromPartition(partitionIndex int, memberIndex int) *T {
+	if partitionIndex >= 0 && memberIndex >= 0 {
+		return &m.partitions[partitionIndex].Members[memberIndex]
+	}
+	return nil
+}
+
+func (m *Manager[T]) lookupMember(member T) (int, int) {
+	var (
+		partitionIndex int
+		memberIndex    int
+	)
+
+	// check all partitions for nodes
+	for _, partition := range m.partitions {
+		memberIndex = slices.IndexFunc(partition.Members, func(testMember T) bool {
+			return member == testMember
+		})
+		// we found the node in the partition so return
+		if memberIndex >= 0 {
+			return partitionIndex, memberIndex
+		}
+		partitionIndex += 1
+	}
+	// return negative values to indicate the node was not found
+	return -1, -1
+}
+
+type NodeManager = Manager[nodes.Node]
+type DefaultManager = Manager[string]
diff --git a/internal/partitions/partitions.go b/internal/partitions/partitions.go
new file mode 100644
index 0000000..7e6607e
--- /dev/null
+++ b/internal/partitions/partitions.go
@@ -0,0 +1,11 @@
+package partitions
+
+import "github.com/davidallendj/partitions/internal/nodes"
+
+type partition[T comparable] struct {
+	ID      string
+	Members []T
+}
+
+type nodePartition = partition[nodes.Node]
+type defaultPartition = partition[string]
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..62a249f
--- /dev/null
+++ b/main.go
@@ -0,0 +1,71 @@
+package main
+
+import (
+	"encoding/json"
+
+	"github.com/davidallendj/partitions/internal/groups"
+	"github.com/davidallendj/partitions/internal/partitions"
+	"github.com/rs/zerolog/log"
+)
+
+func main() {
+	var (
+		pm = partitions.DefaultManager{}
+		n1 = "nid0001"
+		n2 = "nid0002"
+		n3 = "nid0003"
+		p1 = "test1"
+		p2 = "test2"
+	)
+
+	// create new partitions with partition manager while testing adding
+	// the same partition multiple times
+	unwrapError(pm.CreatePartition(p1, []string{n3}))
+	unwrapError(pm.CreatePartition(p2, nil))
+	unwrapError(pm.CreatePartition(p2, nil))
+
+	// try and put the same node in multiple partitions which should cause error
+	unwrapError(pm.AddNodeToPartition(p1, n1))
+	unwrapError(pm.AddNodeToPartition(p1, n1))
+	unwrapError(pm.AddNodeToPartition(p2, n2))
+
+	// try and put the same node in multiple groups
+	var (
+		g1 = groups.Group{
+			Name:   "group1",
+			Labels: []string{n1, n2, "hello"},
+		}
+		g2 = groups.Group{
+			Name:   "group2",
+			Labels: []string{n1, n3, "world"},
+		}
+	)
+
+	g1NodeIDs := ToJSON(g1.GetNodeIDs(&pm))
+	g1PartitionIDs := ToJSON(g1.GetPartitions(&pm))
+	g2NodeIDs := ToJSON(g2.GetNodeIDs(&pm))
+	g2PartitionIDs := ToJSON(g2.GetPartitions(&pm))
+
+	log.Info().Any("manager.partitions", pm.GetPartitions()).Msg("partition manager")
+	log.Info().
+		Any("group", g1).
+		Any("found node IDs in manager", g1NodeIDs).
+		Any("partitions containing found nodes", g1PartitionIDs).
+		Msg("group 1")
+	log.Info().
+		Any("group", g2).
+		Any("found node IDs in manager", g2NodeIDs).
+		Any("partitions containing found nodes", g2PartitionIDs).
+		Msg("group 2")
+}
+
+func unwrapError(err error) {
+	if err != nil {
+		log.Error().Err(err).Msg("something went wrong...")
+	}
+}
+
+func ToJSON(v any) string {
+	b, _ := json.Marshal(v)
+	return string(b)
+}
diff --git a/partitions b/partitions
new file mode 100755
index 0000000..a6ff178
Binary files /dev/null and b/partitions differ