package influxdb

import (
	"fmt"
	"io"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/influxdata/telegraf/plugins/outputs/influxdb/client"
	"github.com/influxdata/telegraf/testutil"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestIdentQuoting(t *testing.T) {
	var testCases = []struct {
		database string
		expected string
	}{
		{"x-y", `CREATE DATABASE "x-y"`},
		{`x"y`, `CREATE DATABASE "x\"y"`},
		{"x\ny", `CREATE DATABASE "x\ny"`},
		{`x\y`, `CREATE DATABASE "x\\y"`},
	}

	for _, tc := range testCases {
		ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			r.ParseForm()
			q := r.Form.Get("q")
			assert.Equal(t, tc.expected, q)

			w.WriteHeader(http.StatusOK)
			w.Header().Set("Content-Type", "application/json")
			fmt.Fprintln(w, `{"results":[{}]}`)
		}))
		defer ts.Close()

		i := InfluxDB{
			URLs:     []string{ts.URL},
			Database: tc.database,
		}

		err := i.Connect()
		require.NoError(t, err)
		require.NoError(t, i.Close())
	}
}

func TestUDPInflux(t *testing.T) {
	i := InfluxDB{
		URLs: []string{"udp://localhost:8089"},
	}

	err := i.Connect()
	require.NoError(t, err)
	err = i.Write(testutil.MockMetrics())
	require.NoError(t, err)
	require.NoError(t, i.Close())
}

func TestHTTPInflux(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/write":
			// test that database is set properly
			if r.FormValue("db") != "test" {
				w.WriteHeader(http.StatusTeapot)
				w.Header().Set("Content-Type", "application/json")
			}
			// test that user agent is set properly
			if r.UserAgent() != "telegraf" {
				w.WriteHeader(http.StatusTeapot)
				w.Header().Set("Content-Type", "application/json")
			}
			w.WriteHeader(http.StatusNoContent)
			w.Header().Set("Content-Type", "application/json")
		case "/query":
			w.WriteHeader(http.StatusOK)
			w.Header().Set("Content-Type", "application/json")
			fmt.Fprintln(w, `{"results":[{}]}`)
		}
	}))
	defer ts.Close()

	i := newInflux()
	i.URLs = []string{ts.URL}
	i.Database = "test"
	i.UserAgent = "telegraf"

	err := i.Connect()
	require.NoError(t, err)
	err = i.Write(testutil.MockMetrics())
	require.NoError(t, err)
	require.NoError(t, i.Close())
}

func TestUDPConnectError(t *testing.T) {
	i := InfluxDB{
		URLs: []string{"udp://foobar:8089"},
	}

	err := i.Connect()
	require.Error(t, err)

	i = InfluxDB{
		URLs: []string{"udp://localhost:9999999"},
	}

	err = i.Connect()
	require.Error(t, err)
}

func TestHTTPConnectError_InvalidURL(t *testing.T) {
	i := InfluxDB{
		URLs: []string{"http://foobar:8089"},
	}

	err := i.Connect()
	require.Error(t, err)

	i = InfluxDB{
		URLs: []string{"http://localhost:9999999"},
	}

	err = i.Connect()
	require.Error(t, err)
}

func TestHTTPConnectError_DatabaseCreateFail(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/query":
			w.WriteHeader(http.StatusNotFound)
			w.Header().Set("Content-Type", "application/json")
			fmt.Fprintln(w, `{"results":[{}],"error":"test error"}`)
		}
	}))
	defer ts.Close()

	i := InfluxDB{
		URLs:     []string{ts.URL},
		Database: "test",
	}

	// database creation errors do not return an error from Connect
	// they are only logged.
	err := i.Connect()
	require.NoError(t, err)
	require.NoError(t, i.Close())
}

func TestHTTPError_DatabaseNotFound(t *testing.T) {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/write":
			w.WriteHeader(http.StatusNotFound)
			w.Header().Set("Content-Type", "application/json")
			fmt.Fprintln(w, `{"results":[{}],"error":"database not found"}`)
		case "/query":
			w.WriteHeader(http.StatusNotFound)
			w.Header().Set("Content-Type", "application/json")
			fmt.Fprintln(w, `{"results":[{}],"error":"database not found"}`)
		}
	}))
	defer ts.Close()

	i := InfluxDB{
		URLs:     []string{ts.URL},
		Database: "test",
	}

	err := i.Connect()
	require.NoError(t, err)
	err = i.Write(testutil.MockMetrics())
	require.Error(t, err)
	require.NoError(t, i.Close())
}

func TestHTTPError_WriteErrors(t *testing.T) {
	var testCases = []struct {
		name        string
		status      int
		contentType string
		body        string
		err         error
	}{
		{
			// HTTP/1.1 400 Bad Request
			// Content-Type: application/json
			// X-Influxdb-Version: 1.3.3
			//
			// {
			//     "error": "partial write: points beyond retention policy dropped=1"
			// }
			name:        "beyond retention policy is not an error",
			status:      http.StatusBadRequest,
			contentType: "application/json",
			body:        `{"error":"partial write: points beyond retention policy dropped=1"}`,
			err:         nil,
		},
		{
			// HTTP/1.1 400 Bad Request
			// Content-Type: application/json
			// X-Influxdb-Version: 1.3.3
			//
			// {
			//     "error": "unable to parse 'foo bar=': missing field value"
			// }
			name:        "unable to parse is not an error",
			status:      http.StatusBadRequest,
			contentType: "application/json",
			body:        `{"error":"unable to parse 'foo bar=': missing field value"}`,
			err:         nil,
		},
		{
			// HTTP/1.1 400 Bad Request
			// Content-Type: application/json
			// X-Influxdb-Version: 1.3.3
			//
			// {
			//     "error": "partial write: field type conflict: input field \"bar\" on measurement \"foo\" is type float, already exists as type integer dropped=1"
			// }
			name:        "field type conflict is not an error",
			status:      http.StatusBadRequest,
			contentType: "application/json",
			body:        `{"error": "partial write: field type conflict: input field \"bar\" on measurement \"foo\" is type float, already exists as type integer dropped=1"}`,
			err:         nil,
		},
		{
			// HTTP/1.1 500 Internal Server Error
			// Content-Type: application/json
			// X-Influxdb-Version: 1.3.3-c1.3.3
			//
			// {
			//     "error": "write failed: hinted handoff queue not empty"
			// }
			name:        "hinted handoff queue not empty is not an error",
			status:      http.StatusInternalServerError,
			contentType: "application/json",
			body:        `{"error":"write failed: hinted handoff queue not empty"}`,
			err:         nil,
		},
		{
			// HTTP/1.1 500 Internal Server Error
			// Content-Type: application/json
			// X-Influxdb-Version: 1.3.3-c1.3.3
			//
			// {
			//     "error": "partial write"
			// }
			name:        "plain partial write is an error",
			status:      http.StatusInternalServerError,
			contentType: "application/json",
			body:        `{"error":"partial write"}`,
			err:         fmt.Errorf("Could not write to any InfluxDB server in cluster"),
		},
	}

	for _, tt := range testCases {
		t.Run(tt.name, func(t *testing.T) {
			ts := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
				rw.WriteHeader(tt.status)
				rw.Header().Set("Content-Type", tt.contentType)
				fmt.Fprintln(rw, tt.body)
			}))
			defer ts.Close()

			influx := InfluxDB{
				URLs:     []string{ts.URL},
				Database: "test",
			}

			err := influx.Connect()
			require.NoError(t, err)
			err = influx.Write(testutil.MockMetrics())
			require.Equal(t, tt.err, err)
			require.NoError(t, influx.Close())
		})
	}
}

type MockClient struct {
	writeStreamCalled int
	contentLength     int
}

func (m *MockClient) Query(command string) error {
	panic("not implemented")
}

func (m *MockClient) Write(b []byte) (int, error) {
	panic("not implemented")
}

func (m *MockClient) WriteWithParams(b []byte, params client.WriteParams) (int, error) {
	panic("not implemented")
}

func (m *MockClient) WriteStream(b io.Reader, contentLength int) (int, error) {
	m.writeStreamCalled++
	m.contentLength = contentLength
	return 0, nil
}

func (m *MockClient) WriteStreamWithParams(b io.Reader, contentLength int, params client.WriteParams) (int, error) {
	panic("not implemented")
}

func (m *MockClient) Close() error {
	panic("not implemented")
}