package dsl_test

import (
	"errors"
	"fmt"
	"github.com/BytemarkHosting/go-pdns/pipe/backend"
	. "github.com/BytemarkHosting/go-pdns/pipe/dsl"
	h "github.com/BytemarkHosting/go-pdns/pipe/test_helpers"
	"strings"
	"testing"
)

func ReplyHandler(x string) func(c *Context) {
	return func(c *Context) { c.Reply(x) }
}

func NullHandler(c *Context) {}

var ErrorReplyError = errors.New("Foo")

func ErrorReplyHandler(c *Context) { c.Error = ErrorReplyError }

func SOAQuery() *backend.Query {
	q := h.FakeQuery(3)
	q.QName = "example.com"
	q.QType = "SOA"
	return q
}

func AssertTableEntry(t *testing.T, d *DSL, qtype, matcher, msg string) {
	table := qtype + "\t:\t" + matcher + "\n"
	h.AssertEqualString(t, table, d.String(), msg)
}

func AssertLookup(t *testing.T, d *DSL, q *backend.Query, n int, err error) []*backend.Response {
	rsp, rspErr := d.Lookup(q)
	if err == nil {
		h.RefuteError(t, err, "Lookup shouldn't return error")
	} else if rspErr == nil {
		t.Logf("Expected error %s but no error was returned", err)
		t.FailNow()
	} else {
		h.AssertEqualString(t, err.Error(), rspErr.Error(), "Expected error not returned")
	}

	rspStrs := []string{}
	for _, r := range rsp {
		r.ProtocolVersion = 1
		str, err := r.String()
		h.RefuteError(t, err, "sanity")
		rspStrs = append(rspStrs, str)
	}

	h.AssertEqualInt(t, n, len(rsp), fmt.Sprintf("One response expected, got:\n%s", strings.Join(rspStrs, "")))
	return rsp
}

// Don't test all the autogenerated helpers explicitly, just a common one.
func TestAutogeneratedExampleRegistersCorrectCallbackWhenRun(t *testing.T) {
	d := New()
	d.SOA(`example\.com`, NullHandler)
	AssertTableEntry(t, d, "SOA", `^(?i)example\.com$`, "SOA callback not registered")
}

func TestDefaultTTLFromNewIsOneHour(t *testing.T) {
	d := New()
	d.SOA(`*`, ReplyHandler("Foo"))
	rsp := AssertLookup(t, d, SOAQuery(), 1, nil)
	h.AssertEqualString(t, "3600", rsp[0].TTL, "Default TTL not honoured")
}

func TestAlternativeTTLCanBeSpecifiedUsingNewWithTTL(t *testing.T) {
	d := NewWithTTL(86400)
	d.SOA(`*`, ReplyHandler("Foo"))
	rsp := AssertLookup(t, d, SOAQuery(), 1, nil)
	h.AssertEqualString(t, "86400", rsp[0].TTL, "Custom TTL not honoured")
}

func TestBeforeCallbackIsCalledIfSpecified(t *testing.T) {
	d := New()
	d.Before(ReplyHandler("Before"))
	d.SOA(`*`, ReplyHandler("SOA 1"))
	d.SOA(`*`, ReplyHandler("SOA 2"))
	rsp := AssertLookup(t, d, SOAQuery(), 4, nil)
	h.AssertEqualString(t, "Before", rsp[0].Content, "First Before not called")
	h.AssertEqualString(t, "SOA 1", rsp[1].Content, "First SOA not called")
	h.AssertEqualString(t, "Before", rsp[2].Content, "Second Before not called")
	h.AssertEqualString(t, "SOA 2", rsp[3].Content, "Second SOA not called")
}

func TestLookupCallbackOrderIsDefined(t *testing.T) {
	d := New()
	d.SOA(`*`, ReplyHandler("SOA 1"))
	d.MX(`*`, ReplyHandler("MX 1"))
	d.SOA(`*`, ReplyHandler("SOA 2"))
	d.SOA(`*`, ReplyHandler("SOA 3"))
	d.AAAA(`*`, ReplyHandler("AAAA 1"))
	d.A(`*`, ReplyHandler("AAAA 2"))
	rsp := AssertLookup(t, d, h.FakeQuery(1), 6, nil)
	msg := "Order is wrong"
	h.AssertEqualString(t, "SOA 1", rsp[0].Content, msg)
	h.AssertEqualString(t, "SOA 2", rsp[1].Content, msg)
	h.AssertEqualString(t, "SOA 3", rsp[2].Content, msg)
	h.AssertEqualString(t, "MX 1", rsp[3].Content, msg)
	h.AssertEqualString(t, "AAAA 1", rsp[4].Content, msg)
	h.AssertEqualString(t, "AAAA 2", rsp[5].Content, msg)
}

func TestOnlyMatchingCallbacksAreRun(t *testing.T) {
	d := New()
	d.SOA(`example\.com`, ReplyHandler("Good"))
	d.SOA(`example\.org`, ReplyHandler("Bad"))
	rsp := AssertLookup(t, d, SOAQuery(), 1, nil)
	h.AssertEqualString(t, "Good", rsp[0].Content, "Wrong callback run")
}

func TestOnlyCallbacksOfTheRightQTypeAreRun(t *testing.T) {
	d := New()
	d.SOA(`example\.com`, ReplyHandler("Good"))
	d.NS(`example\.com`, ReplyHandler("Bad"))
	rsp := AssertLookup(t, d, SOAQuery(), 1, nil)
	h.AssertEqualString(t, "Good", rsp[0].Content, "Wrong callback run")
}

func TestCaptureGroupsArePutIntoContextMatches(t *testing.T) {
	d := New()
	var captures []string
	d.SOA(`([a-z]{3})\.([a-z]{3})\.([a-z]{3})\.example\.com`, func(c *Context) {
		captures = c.Matches
		c.Reply("OK")
	})
	q := SOAQuery()
	q.QName = "BAZ.bar.foo.example.com"
	rsp := AssertLookup(t, d, q, 1, nil)
	h.AssertEqualInt(t, 3, len(captures), "Wrong number of match groups returned")
	h.AssertEqualString(t, "OK", rsp[0].Content, "Wrong callback run?")
	// case-insensitive, so we don't mangle these
	h.AssertEqualString(t, "BAZ", captures[0], "Part 1 not captured")
	h.AssertEqualString(t, "bar", captures[1], "Part 2 not captured")
	h.AssertEqualString(t, "foo", captures[2], "Part 3 not captured")
}

func TestBeforeCanModifyCaptureGroups(t *testing.T) {
	d := New()
	d.Before(func(c *Context) { c.Matches = append(c.Matches, "modify-cg") })
	d.SOA(`*`, func(c *Context) { c.Reply(c.Matches[0]) })
	rsp := AssertLookup(t, d, SOAQuery(), 1, nil)
	h.AssertEqualString(t, "modify-cg", rsp[0].Content, "Capture modification lost")
}

func TestChangesToMatchesInOrdinaryCallbacksDoNotPersist(t *testing.T) {
	d := New()
	var ok bool

	d.SOA(`*`, func(c *Context) { c.Matches = append(c.Matches, "Bad") })
	d.SOA(`*`, func(c *Context) { ok = (len(c.Matches) == 0) })
	AssertLookup(t, d, SOAQuery(), 0, nil)
	h.Assert(t, ok, "Change was persisted")
}

func TestCallbackReturningErrorIsReported(t *testing.T) {
	d := New()
	d.SOA(`*`, ErrorReplyHandler)
	AssertLookup(t, d, SOAQuery(), 0, ErrorReplyError)
}

func TestCallbackReturningErrorBlanksAnswers(t *testing.T) {
	d := New()
	d.SOA(`*`, ReplyHandler("Foo"))
	d.SOA(`*`, ErrorReplyHandler)
	AssertLookup(t, d, SOAQuery(), 0, ErrorReplyError)
}

func TestCallbackReturningErrorStopsLaterCallbacksFromRunning(t *testing.T) {
	d := New()
	ok := true
	d.SOA(`*`, ErrorReplyHandler)
	d.SOA(`*`, func(c *Context) { ok = false })
	AssertLookup(t, d, SOAQuery(), 0, ErrorReplyError)
	h.Assert(t, ok, "Later callback was run")
}