// ingestion/internal/wiki/merge_test.go
package wiki

import (
	"strings"
	"testing"

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

func TestMerge_BulletSectionsUnion(t *testing.T) {
	a := Page{Path: "wiki/concepts/foo.md", Content: "---\ntitle: Foo\n---\n\n## Related Concepts\n\n- [[bar|Bar]]\n"}
	b := Page{Path: "wiki/concepts/foo.md", Content: "---\ntitle: Foo\n---\n\n## Related Concepts\n\n- [[bar|Bar]]\n- [[baz|Baz]]\n"}

	got := Merge(a, b)
	assert.Contains(t, got.Content, "[[bar|Bar]]")
	assert.Contains(t, got.Content, "[[baz|Baz]]")
	assert.Equal(t, 1, strings.Count(got.Content, "[[bar|Bar]]"))
}

func TestMerge_AppendSections(t *testing.T) {
	a := Page{Path: "wiki/concepts/foo.md", Content: "---\ntitle: Foo\n---\n\n## Evolving Notes\n\nFirst note.\n"}
	b := Page{Path: "wiki/concepts/foo.md", Content: "---\ntitle: Foo\n---\n\n## Evolving Notes\n\nSecond note.\n"}

	got := Merge(a, b)
	assert.Contains(t, got.Content, "First note.")
	assert.Contains(t, got.Content, "Second note.")
}

func TestMerge_KeepFirstForOtherSections(t *testing.T) {
	a := Page{Path: "wiki/concepts/foo.md", Content: "---\ntitle: Foo\n---\n\n## Definition\n\nFirst definition.\n"}
	b := Page{Path: "wiki/concepts/foo.md", Content: "---\ntitle: Foo\n---\n\n## Definition\n\nSecond definition.\n"}

	got := Merge(a, b)
	assert.Contains(t, got.Content, "First definition.")
	assert.NotContains(t, got.Content, "Second definition.")
}

func TestMerge_NewSectionFromB(t *testing.T) {
	a := Page{Path: "wiki/concepts/foo.md", Content: "---\ntitle: Foo\n---\n\n## Definition\n\nA thing.\n"}
	b := Page{Path: "wiki/concepts/foo.md", Content: "---\ntitle: Foo\n---\n\n## Why It Matters\n\nBecause reasons.\n"}

	got := Merge(a, b)
	assert.Contains(t, got.Content, "A thing.")
	assert.Contains(t, got.Content, "Because reasons.")
}

func TestMerge_KeepsFrontmatterFromA(t *testing.T) {
	a := Page{Path: "p.md", Content: "---\ntitle: A\nlast_updated: 2026-01-01\n---\n\n## Definition\n\nA.\n"}
	b := Page{Path: "p.md", Content: "---\ntitle: B\nlast_updated: 2026-06-01\n---\n\n## Definition\n\nB.\n"}

	got := Merge(a, b)
	assert.Contains(t, got.Content, "title: A")
	assert.NotContains(t, got.Content, "title: B")
}