package html_test

import (
	"bytes"
	"code.squareroundforest.org/arpio/html"
	. "code.squareroundforest.org/arpio/html/tags"
	"errors"
	"strings"
	"testing"
)

type failingWriter struct {
	after int
}

func failWriteAfter(n int) *failingWriter {
	return &failingWriter{n}
}

func (w *failingWriter) Write(p []byte) (int, error) {
	w.after -= len(p)
	if w.after < 0 {
		return len(p) + w.after, errors.New("test error")
	}

	return len(p), nil
}

func TestRender(t *testing.T) {
	t.Run("merge render guides", func(t *testing.T) {
		foo := html.Inline(html.Verbatim(NewTag("foo")))
		foo = foo("<bar><baz></bar>")

		var b bytes.Buffer
		if err := html.RenderIndent(&b, "\t", 0, foo); err != nil {
			t.Fatal(err)
		}

		if b.String() != "<foo><bar><baz></bar></foo>" {
			t.Fatal(b.String())
		}
	})

	t.Run("attribute escaping", func(t *testing.T) {
		span := Span(Attr("foo", "bar=\"&\""))

		var b bytes.Buffer
		if err := html.Render(&b, span); err != nil {
			t.Fatal(err)
		}

		if b.String() != "<span foo=\"bar=&quot;&amp;&quot;\"></span>" {
			t.Fatal(b.String())
		}
	})

	t.Run("html escape", func(t *testing.T) {
		t.Run("basic escape", func(t *testing.T) {
			span := Span("<foo>bar&baz</foo>")

			var b bytes.Buffer
			if err := html.Render(&b, span); err != nil {
				t.Fatal(err)
			}

			if b.String() != "<span>&lt;foo&gt;bar&amp;baz&lt;/foo&gt;</span>" {
				t.Fatal(b.String())
			}
		})

		t.Run("consecutive spaces", func(t *testing.T) {
			span := Span("consecutive spaces: \"   \"")

			var b bytes.Buffer
			if err := html.Render(&b, span); err != nil {
				t.Fatal(err)
			}

			if b.String() != "<span>consecutive spaces: \"&nbsp;&nbsp;&nbsp;\"</span>" {
				t.Fatal(b.String())
			}
		})
	})

	t.Run("write error", func(t *testing.T) {
		t.Run("fail immediately", func(t *testing.T) {
			div := Div(Span("foo"))
			w := failWriteAfter(0)
			if err := html.Render(w, div); err == nil || !strings.Contains(err.Error(), "test error") {
				t.Fatal()
			}
		})

		t.Run("fail in tag", func(t *testing.T) {
			div := Div(Span("foo"))
			w := failWriteAfter(6)
			if err := html.Render(w, div); err == nil || !strings.Contains(err.Error(), "test error") {
				t.Fatal()
			}
		})

		t.Run("partial text children", func(t *testing.T) {
			div := Div("foo", Div("bar"), "baz")
			w := failWriteAfter(5)
			if err := html.RenderIndent(w, "\t", 0, div); err == nil || !strings.Contains(err.Error(), "test error") {
				t.Fatal()
			}
		})

		t.Run("text children", func(t *testing.T) {
			div := Div("foo", "bar", "baz")
			w := failWriteAfter(5)
			if err := html.RenderIndent(w, "\t", 0, div); err == nil || !strings.Contains(err.Error(), "test error") {
				t.Fatal()
			}
		})
	})

	t.Run("indent", func(t *testing.T) {
		t.Run("simple tag", func(t *testing.T) {
			div := Div(Span("foo"))

			var b bytes.Buffer
			if err := html.RenderIndent(&b, "\t", 0, div); err != nil {
				t.Fatal(err)
			}

			if b.String() != "<div>\n\t<span>foo</span>\n</div>\n" {
				t.Fatal(b.String())
			}
		})

		t.Run("empty tag", func(t *testing.T) {
			div := Div(Br())

			var b bytes.Buffer
			if err := html.RenderIndent(&b, "\t", 0, div); err != nil {
				t.Fatal(err)
			}

			if b.String() != "<div>\n\t<br>\n</div>\n" {
				t.Fatal(b.String())
			}
		})

		t.Run("inline fragment between blocks", func(t *testing.T) {
			div := Div("foo bar baz", Div("qux quux"), "corge")

			var b bytes.Buffer
			if err := html.RenderIndent(&b, "\t", 0, div); err != nil {
				t.Fatal(err)
			}

			if b.String() != "<div>\n\tfoo bar baz\n\t<div>\n\t\tqux quux\n\t</div>\n\tcorge\n</div>\n" {
				t.Fatal(b.String())
			}
		})

		t.Run("block inside inline", func(t *testing.T) {
			div := Div(Span("foo bar baz", Div("qux quux"), "corge"))

			var b bytes.Buffer
			if err := html.RenderIndent(&b, "XYZ", 0, div); err != nil {
				t.Fatal(err)
			}

			if b.String() != "" {
				t.Fatal(b.String())
			}
		})
	})
}