package buffer_test

import (
	"bytes"
	"code.squareroundforest.org/arpio/buffer"
	"errors"
	"io"
	"testing"
)

func TestReadBytes(t *testing.T) {
	for title, cr := range map[string]createReader{"reader": buffer.BufferedReader, "content": testContent} {
		t.Run(title, func(t *testing.T) {
			t.Run("find", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12},
					customContent:      map[int][]byte{12: []byte("123")},
				}

				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("delimiter")
				}

				if !bytes.Equal(b, append(generate(12), []byte("123")...)) {
					t.Fatal("failed to generate right content")
				}
			})

			t.Run("find not", func(t *testing.T) {
				g := &gen{max: 1 << 15}
				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if ok || len(b) != 0 {
					t.Fatal("failed to not find delimiter")
				}
			})

			t.Run("find across segments", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12},
					customContent:      map[int][]byte{12: []byte("123")},
				}

				o := buffer.Options{Pool: buffer.NoPool(14)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("failed to find delimiter")
				}

				if !bytes.Equal(b, append(generate(12), []byte("123")...)) {
					t.Fatal("invalid content")
				}
			})

			t.Run("find across multiple segments", func(t *testing.T) {
				d := generateFrom([]byte("123"), 12)
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{6},
					customContent:      map[int][]byte{6: d},
				}

				o := buffer.Options{Pool: buffer.NoPool(8)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes(d, 64)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("failed to find delimiter")
				}

				if !bytes.Equal(b, append(generate(6), d...)) {
					t.Fatal("invalid content")
				}
			})

			t.Run("find not across segments", func(t *testing.T) {
				g := &gen{max: 1 << 15}
				o := buffer.Options{Pool: buffer.NoPool(15)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 24)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content", len(b), string(b))
				}
			})

			t.Run("find not across multiple segments", func(t *testing.T) {
				g := &gen{max: 1 << 15}
				o := buffer.Options{Pool: buffer.NoPool(15)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content", len(b), string(b))
				}
			})

			t.Run("find not due to max", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12},
					customContent:      map[int][]byte{12: []byte("123")},
				}

				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("8"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}
			})

			t.Run("find partial", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12},
					customContent:      map[int][]byte{12: []byte("12")},
				}

				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}
			})

			t.Run("find partial and then full", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12, 18},
					customContent: map[int][]byte{
						12: []byte("12"),
						18: []byte("123"),
					},
				}

				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 16)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}

				b, ok, err = r.ReadBytes([]byte("123"), 24)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("delimiter")
				}

				check := append(
					append(generate(12), append([]byte("12"), generate(18)[14:]...)...),
					[]byte("123")...,
				)

				if !bytes.Equal(b, check) {
					t.Fatal("invalid content", len(b), string(b), len(check), string(check))
				}
			})

			t.Run("find partial across segments", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{7},
					customContent:      map[int][]byte{7: []byte("12")},
				}

				o := buffer.Options{Pool: buffer.NoPool(8)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}
			})

			t.Run("find partial across multiple segments", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{7},
					customContent:      map[int][]byte{7: []byte("1234567890")},
				}

				o := buffer.Options{Pool: buffer.NoPool(8)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("1234567890123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}
			})

			t.Run("find partial across segments and then full", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{7, 15},
					customContent: map[int][]byte{
						7:  []byte("12"),
						15: []byte("123"),
					},
				}

				o := buffer.Options{Pool: buffer.NoPool(8)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 10)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}

				b, ok, err = r.ReadBytes([]byte("123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("delimiter")
				}

				check := append(
					append(generate(7), append([]byte("12"), generate(15)[9:]...)...),
					[]byte("123")...,
				)

				if !bytes.Equal(b, check) {
					t.Fatal("invalid content", len(b), string(b), len(check), string(check))
				}
			})

			t.Run("find partial across multiple segments and then full", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{7, 22},
					customContent: map[int][]byte{
						7:  []byte("1234567890"),
						22: []byte("1234567890123"),
					},
				}

				o := buffer.Options{Pool: buffer.NoPool(8)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("1234567890123"), 20)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("invalid delimiter found")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}

				b, ok, err = r.ReadBytes([]byte("1234567890123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("delimiter")
				}

				check := append(
					append(append(generate(7), []byte("1234567890")...), generate(22)[17:]...),
					[]byte("1234567890123")...,
				)

				if !bytes.Equal(b, check) {
					t.Fatal("invalid content", len(b), string(b), len(check), string(check))
				}
			})

			t.Run("find partial due to max", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12},
					customContent:      map[int][]byte{12: []byte("123")},
				}

				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 14)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("delimiter")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}
			})

			t.Run("find partial due to max and then full", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12},
					customContent:      map[int][]byte{12: []byte("123")},
				}

				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 14)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("delimiter")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}

				b, ok, err = r.ReadBytes([]byte("123"), 64)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("delimiter")
				}

				if !bytes.Equal(b, append(generate(12), []byte("123")...)) {
					t.Fatal("invalid content")
				}
			})

			t.Run("null delimiter", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12},
					customContent:      map[int][]byte{12: []byte("123")},
				}

				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes(nil, 64)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("failed to find delimiter")
				}

				if len(b) != 0 {
					t.Fatal("failed to generate right content")
				}
			})

			t.Run("single char delimiter", func(t *testing.T) {
				g := &gen{
					max:                1 << 15,
					customContentAfter: []int{12},
					customContent:      map[int][]byte{12: []byte("1")},
				}

				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte{'1'}, 64)
				if err != nil {
					t.Fatal(err)
				}

				if !ok {
					t.Fatal("delimiter")
				}

				if !bytes.Equal(b, append(generate(12), '1')) {
					t.Fatal("failed to generate right content")
				}
			})

			t.Run("large delimiter", func(t *testing.T) {
				src := &gen{
					max:                1 << 18,
					customContentAfter: []int{1<<17 - 3},
					customContent:      map[int][]byte{1<<17 - 3: []byte("123")},
				}

				r := buffer.BufferedReader(src, buffer.Options{Pool: buffer.NoPool(1 << 12)})
				r.ReadBytes([]byte{'1'}, 1<<17+1<<16)
			})

			t.Run("delimiter longer than content", func(t *testing.T) {
				g := &gen{max: 1 << 9}
				o := buffer.Options{Pool: buffer.NoPool(16)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes(generate(1<<10), 1<<11)
				if err != nil {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("delimiter")
				}

				if !bytes.Equal(b, generate(1<<9)) {
					t.Fatal("content")
				}
			})

			t.Run("find not none consumed", func(t *testing.T) {
				g := &gen{}
				o := buffer.Options{Pool: buffer.NoPool(1 << 12)}
				r := cr(g, o)
				b, ok, err := r.ReadBytes([]byte("123"), 64)
				if !errors.Is(err, io.EOF) {
					t.Fatal(err)
				}

				if ok {
					t.Fatal("failed to find delimiter")
				}

				if len(b) != 0 {
					t.Fatal("invalid content")
				}
			})
		})
	}

	t.Run("reader only", func(t *testing.T) {
		cr := buffer.BufferedReader
		t.Run("error before found", func(t *testing.T) {
			g := &gen{
				max:                1 << 15,
				errAfter:           []int{8},
				customContentAfter: []int{12},
				customContent:      map[int][]byte{12: []byte("123")},
			}

			o := buffer.Options{Pool: buffer.NoPool(8)}
			r := cr(g, o)
			b, ok, err := r.ReadBytes([]byte("123"), 64)
			if err != nil {
				t.Fatal(err)
			}

			if ok {
				t.Fatal("delimiter")
			}

			if !bytes.Equal(b, generate(8)) {
				t.Fatal("invalid content")
			}

			b, ok, err = r.ReadBytes([]byte("123"), 64)
			if !errors.Is(err, errTest) {
				t.Fatal("failed to fail", err)
			}

			if ok {
				t.Fatal("delimiter")
			}

			if len(b) != 0 {
				t.Fatal("invalid content")
			}
		})

		t.Run("error when found", func(t *testing.T) {
			g := &gen{
				max:                1 << 15,
				errAfter:           []int{15},
				fastErr:            true,
				customContentAfter: []int{12},
				customContent:      map[int][]byte{12: []byte("123")},
			}

			o := buffer.Options{Pool: buffer.NoPool(8)}
			r := cr(g, o)
			b, ok, err := r.ReadBytes([]byte("123"), 64)
			if err != nil {
				t.Fatal(err)
			}

			if !ok {
				t.Fatal("delimiter", len(b), string(b))
			}

			if !bytes.Equal(b, append(generate(12), []byte("123")...)) {
				t.Fatal("invalid content")
			}

			b, ok, err = r.ReadBytes([]byte("123"), 64)
			if err != nil {
				t.Fatal(err)
			}

			if ok {
				t.Fatal("unexpected delimiter")
			}

			if !bytes.Equal(b, generate(16)[15:]) {
				t.Fatal("invalid content", len(b), string(b))
			}

			b, ok, err = r.ReadBytes([]byte("123"), 64)
			if !errors.Is(err, errTest) {
				t.Fatal(err)
			}

			if ok {
				t.Fatal("unexpected delimiter")
			}

			if len(b) != 0 {
				t.Fatal("invalid content", len(b), string(b))
			}
		})

		t.Run("error after found", func(t *testing.T) {
			g := &gen{
				max:                1 << 15,
				errAfter:           []int{18},
				fastErr:            true,
				customContentAfter: []int{12},
				customContent:      map[int][]byte{12: []byte("123")},
			}

			o := buffer.Options{Pool: buffer.NoPool(8)}
			r := cr(g, o)
			b, ok, err := r.ReadBytes([]byte("123"), 64)
			if err != nil {
				t.Fatal(err)
			}

			if !ok {
				t.Fatal("delimiter", len(b), string(b))
			}

			if !bytes.Equal(b, append(generate(12), []byte("123")...)) {
				t.Fatal("invalid content")
			}

			b, ok, err = r.ReadBytes([]byte("123"), 64)
			if err != nil {
				t.Fatal(err)
			}

			if ok {
				t.Fatal("unexpected delimiter")
			}

			if !bytes.Equal(b, generate(24)[15:]) {
				t.Fatal("invalid content", len(b), string(b))
			}

			b, ok, err = r.ReadBytes([]byte("123"), 64)
			if !errors.Is(err, errTest) {
				t.Fatal(err)
			}

			if ok {
				t.Fatal("unexpected delimiter")
			}

			if len(b) != 0 {
				t.Fatal("invalid content", len(b), string(b))
			}
		})

		t.Run("null read", func(t *testing.T) {
			g := &gen{
				max:                1 << 15,
				nullReadAfter:      []int{8, 8},
				customContentAfter: []int{12},
				customContent:      map[int][]byte{12: []byte("123")},
			}

			o := buffer.Options{Pool: buffer.NoPool(8)}
			r := cr(g, o)
			b, ok, err := r.ReadBytes([]byte("123"), 64)
			if err != nil {
				t.Fatal(err)
			}

			if ok {
				t.Fatal("delimiter")
			}

			if len(b) != 0 {
				t.Fatal("invalid content")
			}

			b, ok, err = r.ReadBytes([]byte("123"), 64)
			if err != nil {
				t.Fatal(err)
			}

			if !ok {
				t.Fatal("delimiter")
			}

			if !bytes.Equal(b, append(generate(12), []byte("123")...)) {
				t.Fatal("failed to generate right content")
			}
		})

		t.Run("find not more than max", func(t *testing.T) {
			g := &gen{
				max:     256,
				fastErr: true,
			}

			o := buffer.Options{Pool: buffer.NoPool(256)}
			r := cr(g, o)
			b, ok, err := r.ReadBytes([]byte("123"), 64)
			if err != nil {
				t.Fatal(err)
			}

			if ok {
				t.Fatal("delimiter")
			}

			if !bytes.Equal(b, generate(64)) {
				t.Fatal("failed to generate right content")
			}
		})
	})
}