// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: PolyForm-Noncommercial-1.0.0

package post

import (
	"strings"
	"testing"
	"time"

	"sourcedock.dev/petrbalvin/interpres/v2"
	"sourcedock.dev/petrbalvin/volumen/internal/fediverse"
	"sourcedock.dev/petrbalvin/volumen/internal/frontmatter"
)

func frontmatterMeta(m map[string]any) *frontmatter.Meta {
	meta := frontmatter.NewMeta()
	for k, v := range m {
		meta.Set(k, v)
	}
	return meta
}

func frontmatterPost(m map[string]any) *Post {
	return New(frontmatterMeta(m), "")
}

func mustParse(t *testing.T, content string) *Post {
	t.Helper()
	p, err := Parse(content)
	if err != nil {
		t.Fatalf("post.Parse: %v", err)
	}
	return p
}

const sample = `+++
title = "Ahoj světe"
slug = "ahoj-svete"
lang = "cs"
author = "Petr"
tags = ["go", "blog"]
date = 2026-08-18
series = "Série"
series_order = 2
cover = "/media/cover.webp"
cover_alt = "alt"
cover_caption = "caption"
fediverse_creator = "@petr@mastodon.social"
aliases = ["old-slug"]

[translations]
en = "hello-world"
+++

# Hlavička

První odstavec s dostatkem slov pro shrnutí, který popisuje obsah
celého článku a nemá nadpis, takže se z něj dá odvodit excerpt.

## Sekce

Další text.
`

func TestParseBasics(t *testing.T) {
	p := mustParse(t, sample)
	if p.Slug() != "ahoj-svete" {
		t.Fatalf("slug = %q", p.Slug())
	}
	if p.Title() != "Ahoj světe" || p.Lang() != "cs" || p.Author() != "Petr" {
		t.Fatalf("title/lang/author wrong")
	}
	if tags := p.Tags(); len(tags) != 2 || tags[0] != "go" || tags[1] != "blog" {
		t.Fatalf("tags = %v", tags)
	}
	if p.Draft() || p.AllLangs() {
		t.Fatal("draft/all_langs should be false")
	}
	if p.Translations()["en"] != "hello-world" {
		t.Fatalf("translations = %v", p.Translations())
	}
	if p.Aliases()[0] != "old-slug" {
		t.Fatalf("aliases = %v", p.Aliases())
	}
	if p.Cover() != "/media/cover.webp" || p.CoverAlt() != "alt" || p.CoverCaption() != "caption" {
		t.Fatal("cover fields wrong")
	}
	if !fediverse.Valid(p.FediverseCreator()) {
		t.Fatal("fediverse creator should be valid")
	}
	if p.Series() != "Série" {
		t.Fatalf("series = %q", p.Series())
	}
	if order, ok := p.SeriesOrder(); !ok || order != 2 {
		t.Fatalf("series_order = %d, %v", order, ok)
	}
	if !strings.HasPrefix(p.Body, "# Hlavička") {
		t.Fatalf("body = %q", p.Body)
	}
}

func TestDateStringAndTimestamp(t *testing.T) {
	p := mustParse(t, sample)
	if p.DateString() != "2026-08-18" {
		t.Fatalf("DateString = %q", p.DateString())
	}
	d, ok := p.PublishedDate()
	if !ok || d.Format("2006-01-02") != "2026-08-18" {
		t.Fatalf("PublishedDate = %v, %v", d, ok)
	}
	ts, ok := p.PublishedTimestamp()
	if !ok {
		t.Fatal("PublishedTimestamp missing")
	}
	want := time.Date(2026, 8, 18, 0, 0, 0, 0, time.UTC).UnixMilli()
	if ts != want {
		t.Fatalf("timestamp = %d, want %d", ts, want)
	}
}

func TestPublishAtAndScheduled(t *testing.T) {
	future := mustParse(t, "+++\npublish_at = 2999-01-01\n+++\nx\n")
	if !future.Scheduled() {
		t.Fatal("future publish_at should be scheduled")
	}
	past := mustParse(t, "+++\npublish_at = 2000-01-01\n+++\nx\n")
	if past.Scheduled() {
		t.Fatal("past publish_at should not be scheduled")
	}
	none := mustParse(t, "+++\ntitle = \"x\"\n+++\nx\n")
	if none.Scheduled() {
		t.Fatal("missing publish_at should not be scheduled")
	}
	if _, ok := none.DueAt(); ok {
		t.Fatal("missing publish_at returned a date")
	}
}

func TestPublishAtStringForms(t *testing.T) {
	p := mustParse(t, "+++\npublish_at = \"2026-02-03\"\n+++\nx\n")
	d, ok := p.DueAt()
	if !ok || d.Format("2006-01-02") != "2026-02-03" {
		t.Fatalf("string publish_at = %v, %v", d, ok)
	}
}

func TestFlagsStrict(t *testing.T) {
	p := mustParse(t, "+++\ndraft = \"true\"\n+++\nx\n")
	if p.Draft() {
		t.Fatal("string draft flag must not count as draft")
	}
	p2 := mustParse(t, "+++\ndraft = true\n+++\nx\n")
	if !p2.Draft() {
		t.Fatal("boolean draft flag should count")
	}
}

func TestReadingTime(t *testing.T) {
	short := New(nil, "one two three")
	if got := short.ReadingTime(); got != 1 {
		t.Fatalf("ReadingTime = %d, want 1", got)
	}
	body := strings.Repeat("word ", 450)
	long := New(nil, body)
	if got := long.ReadingTime(); got != 3 {
		t.Fatalf("ReadingTime = %d, want 3", got)
	}
	empty := New(nil, "")
	if got := empty.ReadingTime(); got != 1 {
		t.Fatalf("empty ReadingTime = %d, want 1", got)
	}
}

func TestExcerptPrefersMetadata(t *testing.T) {
	p := mustParse(t, "+++\nexcerpt = \"Vlastní perex\"\n+++\nbody\n")
	if p.Excerpt() != "Vlastní perex" {
		t.Fatalf("Excerpt = %q", p.Excerpt())
	}
}

func TestDerivedExcerpt(t *testing.T) {
	p := New(nil, "# Head\n\nFirst paragraph with **markdown** and <b>html</b>.\n\nSecond.")
	ex := p.Excerpt()
	if strings.Contains(ex, "*") || strings.Contains(ex, "<") || strings.HasPrefix(ex, "#") {
		t.Fatalf("derived excerpt not cleaned: %q", ex)
	}
	if !strings.Contains(ex, "First paragraph") {
		t.Fatalf("derived excerpt wrong: %q", ex)
	}
}

func TestDerivedExcerptTruncates(t *testing.T) {
	p := New(nil, strings.Repeat("x", 500))
	ex := p.Excerpt()
	if !strings.HasSuffix(ex, "…") {
		t.Fatalf("excerpt not truncated: %q", ex)
	}
	if len([]rune(ex)) != 201 {
		t.Fatalf("excerpt length = %d, want 201", len([]rune(ex)))
	}
}

func TestHTMLAndTOCCached(t *testing.T) {
	p := mustParse(t, "+++\ntitle = \"x\"\n+++\n# H\n\nText\n")
	h1, err := p.HTML()
	if err != nil {
		t.Fatalf("HTML: %v", err)
	}
	h2, err := p.HTML()
	if err != nil || h1 != h2 {
		t.Fatalf("HTML not cached: %q vs %q", h1, h2)
	}
	toc, err := p.TOC()
	if err != nil {
		t.Fatalf("TOC: %v", err)
	}
	if !strings.Contains(toc, `href="#h"`) {
		t.Fatalf("toc = %q", toc)
	}
}

func TestToFileRoundTrip(t *testing.T) {
	p := mustParse(t, sample)
	out, err := p.ToFile()
	if err != nil {
		t.Fatalf("ToFile: %v", err)
	}
	p2 := mustParse(t, out)
	if p2.Title() != p.Title() || p2.Slug() != p.Slug() || p2.Body != p.Body {
		t.Fatal("round-trip lost data")
	}
}

func TestCivilDateVariants(t *testing.T) {
	meta := frontmatterMeta(map[string]any{
		"date": interpres.LocalDate{Time: time.Date(2026, 3, 4, 0, 0, 0, 0, time.UTC)},
	})
	if got := New(meta, "").DateString(); got != "2026-03-04" {
		t.Fatalf("LocalDate DateString = %q", got)
	}
	meta = frontmatterMeta(map[string]any{"date": "2026-03-05"})
	if got := New(meta, "").DateString(); got != "2026-03-05" {
		t.Fatalf("string DateString = %q", got)
	}
	meta = frontmatterMeta(map[string]any{"date": 42})
	if got := New(meta, "").DateString(); got != "42" {
		t.Fatalf("int DateString = %q", got)
	}
}

func TestFediverseCreatorValidation(t *testing.T) {
	if !fediverse.Valid("@user@host.social") {
		t.Fatal("valid handle rejected")
	}
	for _, bad := range []string{"user@host", "@user@", "@@host", "@us er@host", ""} {
		if fediverse.Valid(bad) {
			t.Fatalf("invalid handle accepted: %q", bad)
		}
	}
}

func TestDOIORCIDReservedAndReadable(t *testing.T) {
	p := mustParse(t, "+++\nslug = \"paper\"\ndoi = \"10.1000/xyz\"\norcid = \"0000-0002-1825-0097\"\nmethod = \"gravimetric\"\n+++\nx\n")
	if p.DOI() != "10.1000/xyz" {
		t.Fatalf("DOI = %q", p.DOI())
	}
	if p.ORCID() != "0000-0002-1825-0097" {
		t.Fatalf("ORCID = %q", p.ORCID())
	}
	// The identifiers are reserved: only the author's own key reaches
	// the fields object.
	fields := p.CustomFields()
	if _, present := fields["doi"]; present {
		t.Fatal("doi leaked into custom fields")
	}
	if _, present := fields["orcid"]; present {
		t.Fatal("orcid leaked into custom fields")
	}
	if fields["method"] != "gravimetric" {
		t.Fatalf("custom field lost: %v", fields)
	}
}

func TestSeriesOrderCoercions(t *testing.T) {
	p := frontmatterPost(map[string]any{"series_order": "7"})
	if order, ok := p.SeriesOrder(); !ok || order != 7 {
		t.Fatalf("string series_order = %d, %v", order, ok)
	}
	p = frontmatterPost(map[string]any{"series_order": 3.9})
	if order, ok := p.SeriesOrder(); !ok || order != 3 {
		t.Fatalf("float series_order = %d, %v", order, ok)
	}
	p = frontmatterPost(map[string]any{"series_order": "x"})
	if _, ok := p.SeriesOrder(); ok {
		t.Fatal("garbage series_order accepted")
	}
}

func TestUnparseablePublishAtWithholdsThePost(t *testing.T) {
	// A typo in publish_at must not publish the post early: it is
	// withheld, and validate reports it.
	p := mustParse(t, "+++\npublish_at = \"18/09/2026\"\n+++\nx\n")
	if p.Published() {
		t.Fatal("a post with an unreadable publish_at was published")
	}
	if !p.Scheduled() {
		t.Fatal("a post with an unreadable publish_at was not withheld")
	}
	if _, ok := p.DueAt(); ok {
		t.Fatal("an unreadable publish_at produced a date")
	}
}

func TestEmptyPublishAtIsPublished(t *testing.T) {
	p := mustParse(t, "+++\npublish_at = \"\"\n+++\nx\n")
	if !p.Published() {
		t.Fatal("an empty publish_at withheld the post")
	}
}

func TestStatusPrecedence(t *testing.T) {
	draft := mustParse(t, "+++\ndraft = true\npublish_at = 2999-01-01\n+++\nx\n")
	if draft.Status() != StatusDraft {
		t.Fatal("a draft outranks a scheduled post")
	}
	if draft.Published() {
		t.Fatal("a draft was published")
	}
}

func TestCloneIsIndependent(t *testing.T) {
	original := mustParse(t, "+++\ntitle = \"A\"\ntags = [\"go\", \"blog\"]\n[extra]\nkey = \"value\"\n+++\nbody\n")
	clone := original.Clone()
	clone.Metadata.Set("title", "B")
	clone.Metadata.Set("tags", []string{"other"})
	if table, ok := clone.Metadata.Get("extra"); ok {
		if m, isMap := table.(map[string]any); isMap {
			m["key"] = "changed"
		}
	}
	title, _ := original.Metadata.Get("title")
	if title != "A" {
		t.Fatalf("the clone wrote through to the original: title = %v", title)
	}
	if got := original.Tags(); len(got) != 2 || got[0] != "go" {
		t.Fatalf("the clone shares the tag list: %v", got)
	}
	if table, ok := original.Metadata.Get("extra"); ok {
		if m, isMap := table.(map[string]any); isMap && m["key"] != "value" {
			t.Fatalf("the clone shares the nested table: %v", m)
		}
	}
	if clone.Path != original.Path || clone.Body != original.Body {
		t.Fatal("the clone lost the body or the path")
	}
}

func TestStoredExcerptIsNotDerived(t *testing.T) {
	withExcerpt := mustParse(t, "+++\nexcerpt = \"Hand written\"\n+++\nFirst paragraph.\n")
	if withExcerpt.StoredExcerpt() != "Hand written" {
		t.Fatalf("StoredExcerpt = %q", withExcerpt.StoredExcerpt())
	}
	derived := mustParse(t, "+++\ntitle = \"x\"\n+++\nFirst paragraph.\n")
	if derived.StoredExcerpt() != "" {
		t.Fatalf("StoredExcerpt = %q, want empty before the editor fills it", derived.StoredExcerpt())
	}
	if derived.Excerpt() == "" {
		t.Fatal("Excerpt should still derive from the body")
	}
}

func TestPlainTextAndTruncate(t *testing.T) {
	if got := PlainText("<p>Hello <b>world</b></p>", 100); got != "Hello world" {
		t.Fatalf("PlainText = %q", got)
	}
	if got := PlainText("<p>one   two</p>", 100); got != "one two" {
		t.Fatalf("PlainText did not collapse whitespace: %q", got)
	}
	if got := Truncate("abcdefghij", 4); got != "abcd…" {
		t.Fatalf("Truncate = %q", got)
	}
	if got := Truncate("abc", 4); got != "abc" {
		t.Fatalf("Truncate changed a short value: %q", got)
	}
}