package system

import (
	"testing"
	"time"
)

// Test_JoinLeaderNode tests a join operation between a leader and a new node.
func Test_JoinLeaderNode(t *testing.T) {
	leader := mustNewLeaderNode()
	defer leader.Deprovision()

	node := mustNewNode(false)
	defer node.Deprovision()
	if err := node.Join(leader); err != nil {
		t.Fatalf("node failed to join leader: %s", err.Error())
	}
	_, err := node.WaitForLeader()
	if err != nil {
		t.Fatalf("failed waiting for leader: %s", err.Error())
	}
}

// Test_MultiNodeCluster tests formation of a 3-node cluster, and its operation.
func Test_MultiNodeCluster(t *testing.T) {
	node1 := mustNewLeaderNode()
	defer node1.Deprovision()

	node2 := mustNewNode(false)
	defer node2.Deprovision()
	if err := node2.Join(node1); err != nil {
		t.Fatalf("node failed to join leader: %s", err.Error())
	}
	_, err := node2.WaitForLeader()
	if err != nil {
		t.Fatalf("failed waiting for leader: %s", err.Error())
	}

	// Get the new leader, in case it changed.
	c := Cluster{node1, node2}
	leader, err := c.Leader()
	if err != nil {
		t.Fatalf("failed to find cluster leader: %s", err.Error())
	}

	// Get a follower and confirm redirects work properly.
	followers, err := c.Followers()
	if err != nil {
		t.Fatalf("failed to get followers: %s", err.Error())
	}
	if len(followers) != 1 {
		t.Fatalf("got incorrect number of followers: %d", len(followers))
	}

	node3 := mustNewNode(false)
	defer node3.Deprovision()
	if err := node3.Join(leader); err != nil {
		t.Fatalf("node failed to join leader: %s", err.Error())
	}
	_, err = node3.WaitForLeader()
	if err != nil {
		t.Fatalf("failed waiting for leader: %s", err.Error())
	}

	// Get the new leader, in case it changed.
	c = Cluster{node1, node2, node3}
	leader, err = c.Leader()
	if err != nil {
		t.Fatalf("failed to find cluster leader: %s", err.Error())
	}

	// Run queries against cluster.
	tests := []struct {
		stmt     string
		expected string
		execute  bool
	}{
		{
			stmt:     `CREATE TABLE foo (id integer not null primary key, name text)`,
			expected: `{"results":[{}]}`,
			execute:  true,
		},
		{
			stmt:     `INSERT INTO foo(name) VALUES("fiona")`,
			expected: `{"results":[{"last_insert_id":1,"rows_affected":1}]}`,
			execute:  true,
		},
		{
			stmt:     `SELECT * FROM foo`,
			expected: `{"results":[{"columns":["id","name"],"types":["integer","text"],"values":[[1,"fiona"]]}]}`,
			execute:  false,
		},
	}

	for i, tt := range tests {
		var r string
		var err error
		if tt.execute {
			r, err = leader.Execute(tt.stmt)
		} else {
			r, err = leader.Query(tt.stmt)
		}
		if err != nil {
			t.Fatalf(`test %d failed "%s": %s`, i, tt.stmt, err.Error())
		}
		if r != tt.expected {
			t.Fatalf(`test %d received wrong result "%s" got: %s exp: %s`, i, tt.stmt, r, tt.expected)
		}
	}

	// Kill the leader and wait for the new leader.
	leader.Deprovision()
	c.RemoveNode(leader)
	leader, err = c.WaitForNewLeader(leader)
	if err != nil {
		t.Fatalf("failed to find new cluster leader after killing leader: %s", err.Error())
	}

	// Run queries against the now 2-node cluster.
	tests = []struct {
		stmt     string
		expected string
		execute  bool
	}{
		{
			stmt:     `CREATE TABLE foo (id integer not null primary key, name text)`,
			expected: `{"results":[{"error":"table foo already exists"}]}`,
			execute:  true,
		},
		{
			stmt:     `INSERT INTO foo(name) VALUES("sinead")`,
			expected: `{"results":[{"last_insert_id":2,"rows_affected":1}]}`,
			execute:  true,
		},
		{
			stmt:     `SELECT * FROM foo`,
			expected: `{"results":[{"columns":["id","name"],"types":["integer","text"],"values":[[1,"fiona"],[2,"sinead"]]}]}`,
			execute:  false,
		},
	}

	for i, tt := range tests {
		var r string
		var err error
		if tt.execute {
			r, err = leader.Execute(tt.stmt)
		} else {
			r, err = leader.Query(tt.stmt)
		}
		if err != nil {
			t.Fatalf(`test %d failed "%s": %s`, i, tt.stmt, err.Error())
		}
		if r != tt.expected {
			t.Fatalf(`test %d received wrong result "%s" got: %s exp: %s`, i, tt.stmt, r, tt.expected)
		}
	}
}

// Test_MultiNodeClusterSnapshot tests formation of a 3-node cluster, which involves sharing snapshots.
func Test_MultiNodeClusterSnapshot(t *testing.T) {
	node1 := mustNewLeaderNode()
	defer node1.Deprovision()

	if _, err := node1.Execute(`CREATE TABLE foo (id integer not null primary key, name text)`); err != nil {
		t.Fatalf("failed to create table: %s", err.Error())
	}

	// Force snapshots and log truncation to occur.
	for i := 0; i < 3*int(node1.Store.SnapshotThreshold); i++ {
		_, err := node1.Execute(`INSERT INTO foo(name) VALUES("sinead")`)
		if err != nil {
			t.Fatalf(`failed to write records for Snapshot test: %s`, err.Error())
		}
	}

	// Join a second and third nodes, which will get database state via snapshots.
	node2 := mustNewNode(false)
	defer node2.Deprovision()
	if err := node2.Join(node1); err != nil {
		t.Fatalf("node failed to join leader: %s", err.Error())
	}
	_, err := node2.WaitForLeader()
	if err != nil {
		t.Fatalf("failed waiting for leader: %s", err.Error())
	}

	node3 := mustNewNode(false)
	defer node3.Deprovision()
	if err := node3.Join(node1); err != nil {
		t.Fatalf("node failed to join leader: %s", err.Error())
	}
	_, err = node3.WaitForLeader()
	if err != nil {
		t.Fatalf("failed waiting for leader: %s", err.Error())
	}

	// Create a new cluster.
	c := Cluster{node1, node2, node3}

	// Wait for followers to pick up state.
	followers, err := c.Followers()
	if err != nil {
		t.Fatalf("failed to determine followers: %s", err.Error())
	}

	var n int
	var r string
	for _, f := range followers {
		n = 0
		for {
			r, err = f.QueryNoneConsistency(`SELECT COUNT(*) FROM foo`)
			if err != nil {
				t.Fatalf("failed to query follower node: %s", err.Error())
			}

			if r != `{"results":[{"columns":["COUNT(*)"],"types":[""],"values":[[300]]}]}` {
				if n < 20 {
					// Wait, and try again.
					time.Sleep(mustParseDuration("1s"))
					n++
					continue
				}
				t.Fatalf("timed out waiting for snapshot state")
			}
			// The node passed!
			break
		}
	}

	// Kill original node.
	node1.Deprovision()
	c.RemoveNode(node1)
	var leader *Node
	leader, err = c.WaitForNewLeader(node1)
	if err != nil {
		t.Fatalf("failed to find new cluster leader after killing leader: %s", err.Error())
	}

	// Test that the new leader still has the full state.
	n = 0
	for {
		var r string
		r, err = leader.Query(`SELECT COUNT(*) FROM foo`)
		if err != nil {
			t.Fatalf("failed to query follower node: %s", err.Error())
		}

		if r != `{"results":[{"columns":["COUNT(*)"],"types":[""],"values":[[300]]}]}` {
			if n < 10 {
				// Wait, and try again.
				time.Sleep(mustParseDuration("100ms"))
				n++
				continue
			}
			t.Fatalf("timed out waiting for snapshot state")
		}
		// Test passed!
		break
	}
}

// Test_MultiNodeClusterWithNonVoter tests formation of a 4-node cluster, one of which is
// a non-voter
func Test_MultiNodeClusterWithNonVoter(t *testing.T) {
	node1 := mustNewLeaderNode()
	defer node1.Deprovision()

	node2 := mustNewNode(false)
	defer node2.Deprovision()
	if err := node2.Join(node1); err != nil {
		t.Fatalf("node failed to join leader: %s", err.Error())
	}
	_, err := node2.WaitForLeader()
	if err != nil {
		t.Fatalf("failed waiting for leader: %s", err.Error())
	}

	// Get the new leader, in case it changed.
	c := Cluster{node1, node2}
	leader, err := c.Leader()
	if err != nil {
		t.Fatalf("failed to find cluster leader: %s", err.Error())
	}

	node3 := mustNewNode(false)
	defer node3.Deprovision()
	if err := node3.Join(leader); err != nil {
		t.Fatalf("node failed to join leader: %s", err.Error())
	}
	_, err = node3.WaitForLeader()
	if err != nil {
		t.Fatalf("failed waiting for leader: %s", err.Error())
	}

	// Get the new leader, in case it changed.
	c = Cluster{node1, node2, node3}
	leader, err = c.Leader()
	if err != nil {
		t.Fatalf("failed to find cluster leader: %s", err.Error())
	}

	nonVoter := mustNewNode(false)
	defer nonVoter.Deprovision()
	if err := nonVoter.JoinAsNonVoter(leader); err != nil {
		t.Fatalf("non-voting node failed to join leader: %s", err.Error())
	}
	_, err = nonVoter.WaitForLeader()
	if err != nil {
		t.Fatalf("failed waiting for leader: %s", err.Error())
	}
	c = Cluster{node1, node2, node3, nonVoter}

	// Run queries against cluster.
	tests := []struct {
		stmt     string
		expected string
		execute  bool
	}{
		{
			stmt:     `CREATE TABLE foo (id integer not null primary key, name text)`,
			expected: `{"results":[{}]}`,
			execute:  true,
		},
		{
			stmt:     `INSERT INTO foo(name) VALUES("fiona")`,
			expected: `{"results":[{"last_insert_id":1,"rows_affected":1}]}`,
			execute:  true,
		},
		{
			stmt:     `SELECT * FROM foo`,
			expected: `{"results":[{"columns":["id","name"],"types":["integer","text"],"values":[[1,"fiona"]]}]}`,
			execute:  false,
		},
	}

	for i, tt := range tests {
		var r string
		var err error
		if tt.execute {
			r, err = leader.Execute(tt.stmt)
		} else {
			r, err = leader.Query(tt.stmt)
		}
		if err != nil {
			t.Fatalf(`test %d failed "%s": %s`, i, tt.stmt, err.Error())
		}
		if r != tt.expected {
			t.Fatalf(`test %d received wrong result "%s" got: %s exp: %s`, i, tt.stmt, r, tt.expected)
		}
	}

	// Kill the leader and wait for the new leader.
	leader.Deprovision()
	c.RemoveNode(leader)
	leader, err = c.WaitForNewLeader(leader)
	if err != nil {
		t.Fatalf("failed to find new cluster leader after killing leader: %s", err.Error())
	}

	// Run queries against the now 3-node cluster.
	tests = []struct {
		stmt     string
		expected string
		execute  bool
	}{
		{
			stmt:     `CREATE TABLE foo (id integer not null primary key, name text)`,
			expected: `{"results":[{"error":"table foo already exists"}]}`,
			execute:  true,
		},
		{
			stmt:     `INSERT INTO foo(name) VALUES("sinead")`,
			expected: `{"results":[{"last_insert_id":2,"rows_affected":1}]}`,
			execute:  true,
		},
		{
			stmt:     `SELECT * FROM foo`,
			expected: `{"results":[{"columns":["id","name"],"types":["integer","text"],"values":[[1,"fiona"],[2,"sinead"]]}]}`,
			execute:  false,
		},
	}

	for i, tt := range tests {
		var r string
		var err error
		if tt.execute {
			r, err = leader.Execute(tt.stmt)
		} else {
			r, err = leader.Query(tt.stmt)
		}
		if err != nil {
			t.Fatalf(`test %d failed "%s": %s`, i, tt.stmt, err.Error())
		}
		if r != tt.expected {
			t.Fatalf(`test %d received wrong result "%s" got: %s exp: %s`, i, tt.stmt, r, tt.expected)
		}
	}
}