package tui

import (
	"strings"
	"testing"

	tea "github.com/charmbracelet/bubbletea"

	"github.com/lukaszkasprzak/lectio/internal/bible"
	"github.com/lukaszkasprzak/lectio/internal/bookmarks"
	"github.com/lukaszkasprzak/lectio/internal/config"
)

func enReader(t *testing.T) ReaderModel {
	t.Helper()
	t.Setenv("XDG_DATA_HOME", t.TempDir()) // isolate bookmarks + last-place files
	tbl, err := bible.LoadBookTable(nil)
	if err != nil {
		t.Fatal(err)
	}
	cfg := config.Default()
	cfg.UILanguage = "en"
	cfg.SiglaStyle = "english"
	cfg.Versions = []string{"bt", "wuj", "vul", "grb", "drb"}
	return NewReader(cfg, tbl, bookmarks.Open())
}

func key(m ReaderModel, k tea.KeyMsg) ReaderModel {
	nm, _ := m.Update(k)
	return nm.(ReaderModel)
}

// requireCorpus skips the test when corpus `code` is not embedded in this
// build. The optional corpora (wuj, drb, grb) compile in only with
// `-tags fullbible` (or when dropped into the user corpora dir); mirrors the
// helper in internal/bible so these tests run under fullbible and skip -- not
// fail -- on the default vul-only build.
func requireCorpus(t *testing.T, code string) {
	t.Helper()
	if _, ok := bible.Meta(code); !ok {
		t.Skipf("corpus %q not embedded; build with -tags fullbible", code)
	}
}

func runes(s string) tea.KeyMsg { return tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune(s)} }

func win(m ReaderModel, w, h int) ReaderModel {
	nm, _ := m.Update(tea.WindowSizeMsg{Width: w, Height: h})
	return nm.(ReaderModel)
}

func TestReaderBookmarkTagFilter(t *testing.T) {
	m := enReader(t)
	m.marks = []bookmarks.Bookmark{
		{ID: "1", Book: "John", Chapter: 3, Verse: 16, Tags: []string{"faith"}},
		{ID: "2", Book: "Psalms", Chapter: 23, Verse: 1, Tags: []string{"work", "prayer"}},
		{ID: "3", Book: "Matthew", Chapter: 5, Verse: 3, Tags: []string{"prayer"}},
	}
	m.mode = modeBookmarks

	if got := len(m.visMarks()); got != 3 {
		t.Fatalf("unfiltered visible = %d, want 3", got)
	}

	// "/" enters filter input; typing narrows to the two 'prayer' bookmarks.
	m = key(m, runes("/"))
	if !m.markFiltering {
		t.Fatal(`"/" did not enter filter input`)
	}
	for _, c := range []string{"p", "r", "a", "y"} {
		m = key(m, runes(c))
	}
	if got := len(m.visMarks()); got != 2 {
		t.Fatalf(`filter "pray" visible = %d, want 2 (Psalms, Matthew)`, got)
	}

	// Enter keeps the filter and leaves input mode.
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter})
	if m.markFiltering || m.markFilter != "pray" {
		t.Fatalf("after enter: filtering=%v filter=%q", m.markFiltering, m.markFilter)
	}

	// Case-insensitive substring: "WORK" matches the 'work' tag (1 bookmark).
	m.markFilter = "WORK"
	if got := len(m.visMarks()); got != 1 {
		t.Fatalf(`filter "WORK" visible = %d, want 1`, got)
	}

	// Esc clears an active filter, back to all.
	m.markFilter = "work"
	m.markFiltering = false
	m = key(m, tea.KeyMsg{Type: tea.KeyEsc})
	if m.markFilter != "" {
		t.Fatalf("esc did not clear filter, got %q", m.markFilter)
	}
	if got := len(m.visMarks()); got != 3 {
		t.Fatalf("after clearing filter, visible = %d, want 3", got)
	}
}

func TestReaderInit(t *testing.T) {
	m := enReader(t)
	if m.mode != modePick {
		t.Errorf("mode = %v want modePick", m.mode)
	}
	if len(m.matches) != len(m.books) || len(m.books) != 73 {
		t.Errorf("matches=%d books=%d", len(m.matches), len(m.books))
	}
	if len(m.versions) == 0 || m.versions[0] == "bt" {
		t.Errorf("versions = %v (bt must be excluded, non-empty)", m.versions)
	}
}

func TestReaderFilterAndOpen(t *testing.T) {
	m := enReader(t)
	nm, _ := m.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
	m = nm.(ReaderModel)
	m = key(m, runes("jn"))
	// Fuzzy filtering and entering read mode come from the book table and the
	// model's state machine -- independent of any corpus being embedded.
	if len(m.matches) == 0 || m.books[m.matches[0]].Canonical != "John" {
		t.Fatalf("filter 'jn' top = %v", m.books[m.matches[m.pickSel]])
	}
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter})
	if m.mode != modeRead {
		t.Fatalf("did not enter read mode")
	}
	// The reader's first version is wuj (see enReader): its verses and chapter
	// header need the optional wuj corpus embedded.
	t.Run("wuj verses", func(t *testing.T) {
		requireCorpus(t, "wuj")
		if m.books[m.bookIdx].Canonical != "John" || len(m.verses) == 0 {
			t.Errorf("opened book=%q verses=%d", m.books[m.bookIdx].Canonical, len(m.verses))
		}
		if !strings.Contains(m.View(), "1") { // chapter 1 header
			t.Errorf("read view missing chapter:\n%s", m.View())
		}
	})
}

func TestReaderChapterAndVersion(t *testing.T) {
	// Whole-test guard: the reader's first version is wuj (see enReader), so the
	// very first read-mode step below indexes m.chapters[m.chapPos] -- which
	// panics on an empty chapter list when wuj is not embedded. The chapter
	// stepping and version cycling that follow are all a wuj reading session.
	requireCorpus(t, "wuj")
	m := enReader(t)
	nm, _ := m.Update(tea.WindowSizeMsg{Width: 80, Height: 24})
	m = nm.(ReaderModel)
	m = key(m, runes("jn"))
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter})
	firstChap := m.chapters[m.chapPos]
	m = key(m, tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune("n")}) // next chapter
	if m.chapters[m.chapPos] <= firstChap {
		t.Errorf("chapter did not advance: %d -> %d", firstChap, m.chapters[m.chapPos])
	}
	v0 := m.verIdx
	m = key(m, tea.KeyMsg{Type: tea.KeyTab})
	if m.verIdx == v0 {
		t.Errorf("version did not cycle")
	}
	// esc returns to picker
	m = key(m, tea.KeyMsg{Type: tea.KeyEsc})
	if m.mode != modePick {
		t.Errorf("esc did not return to picker")
	}
}

func TestReaderFuzzyScore(t *testing.T) {
	if s, ok := fuzzyScore("gen", "Gen Genesis"); !ok || s < 500 {
		t.Errorf("substring score = %d,%v", s, ok)
	}
	if _, ok := fuzzyScore("xyz", "Gen Genesis"); ok {
		t.Error("xyz should not match Genesis")
	}
	// subsequence: g..s..s across the string
	if _, ok := fuzzyScore("gss", "Gen Genesis"); !ok {
		t.Error("gss should subsequence-match")
	}
}

func TestReaderBookmarkFlow(t *testing.T) {
	// The whole flow reads and bookmarks verses of John from wuj (the reader's
	// first version); "m" only opens the verse picker when len(verses)>0, so
	// the optional wuj corpus must be embedded.
	requireCorpus(t, "wuj")
	m := enReader(t)
	m = win(m, 80, 24)
	m = key(m, runes("jn"))
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter}) // open John 1
	if m.mode != modeRead {
		t.Fatal("did not enter reading")
	}
	// mark: m -> pick a verse -> note box -> enter
	m = key(m, runes("m"))
	if m.mode != modeMarkVerse {
		t.Fatal("m did not enter the verse picker")
	}
	m = key(m, runes("j")) // move the cursor down to John 1:2
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter})
	if m.mode != modeMark {
		t.Fatal("enter did not open the note box")
	}
	m = key(m, runes("hi"))                    // note field
	m = key(m, tea.KeyMsg{Type: tea.KeyTab})   // switch to tags field
	m = key(m, runes("grace"))                 // tags field
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter}) // save
	if m.mode != modeRead {
		t.Fatal("enter did not save + return to reading")
	}
	// list: b
	m = key(m, runes("b"))
	if m.mode != modeBookmarks || len(m.marks) != 1 {
		t.Fatalf("bookmarks mode=%v n=%d", m.mode, len(m.marks))
	}
	if m.marks[0].Book != "John" || m.marks[0].Verse != 2 || m.marks[0].Note != "hi" ||
		len(m.marks[0].Tags) != 1 || m.marks[0].Tags[0] != "grace" {
		t.Errorf("mark = %+v (want John 1:2 note hi tag grace)", m.marks[0])
	}
	if !strings.Contains(m.View(), "John") {
		t.Errorf("bookmarks view missing John:\n%s", m.View())
	}
	// open the bookmark
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter})
	if m.mode != modeRead || m.books[m.bookIdx].Canonical != "John" {
		t.Errorf("jump failed: mode=%v book=%q", m.mode, m.books[m.bookIdx].Canonical)
	}
	// delete via list, with confirmation
	m = key(m, runes("b"))
	m = key(m, runes("d"))
	if !m.confirmDelete {
		t.Fatal("d did not ask for confirmation")
	}
	m = key(m, runes("n")) // cancel
	if m.confirmDelete || len(m.marks) != 1 {
		t.Fatalf("n did not cancel (confirm=%v n=%d)", m.confirmDelete, len(m.marks))
	}
	m = key(m, runes("d"))
	m = key(m, runes("y")) // confirm
	if len(m.marks) != 0 {
		t.Errorf("delete failed, %d remaining", len(m.marks))
	}
}

func TestReaderChapterJump(t *testing.T) {
	// Reads John from wuj (the reader's first version); "c" only opens the
	// chapter-jump prompt when the book has >1 chapter loaded, so the optional
	// wuj corpus must be embedded.
	requireCorpus(t, "wuj")
	m := enReader(t)
	m = win(m, 80, 24)
	m = key(m, runes("jn"))
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter}) // open John 1 (21 chapters)
	if m.mode != modeRead {
		t.Fatal("did not enter reading")
	}
	// c opens the jump prompt
	m = key(m, runes("c"))
	if m.mode != modeChapterJump {
		t.Fatalf("c did not open the chapter-jump prompt (mode=%v)", m.mode)
	}
	if hi := m.chapters[len(m.chapters)-1]; hi != 21 {
		t.Fatalf("John should have 21 chapters, got %d", hi)
	}
	if v := m.View(); !strings.Contains(v, "1-21") || !strings.Contains(v, "go to chapter") {
		t.Errorf("jump prompt missing range/label:\n%s", v)
	}
	// non-digit keys are ignored; only digits accumulate
	m = key(m, runes("x1"))
	m = key(m, runes("4"))
	if m.chapJumpBuf != "14" {
		t.Fatalf("buffer = %q want 14 (non-digits filtered)", m.chapJumpBuf)
	}
	m = key(m, tea.KeyMsg{Type: tea.KeyBackspace})
	m = key(m, runes("2")) // -> "12"
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter})
	if m.mode != modeRead {
		t.Fatalf("enter did not return to reading (mode=%v)", m.mode)
	}
	if m.currentChapter() != 12 {
		t.Errorf("jumped to chapter %d want 12", m.currentChapter())
	}
	if m.scroll != 0 {
		t.Errorf("jump should reset scroll, got %d", m.scroll)
	}

	// out-of-range clamps to the last chapter
	m = key(m, runes("c"))
	m = key(m, runes("999"))
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter})
	if m.currentChapter() != 21 {
		t.Errorf("999 should clamp to 21, got %d", m.currentChapter())
	}

	// esc cancels without moving
	m = key(m, runes("c"))
	m = key(m, runes("3"))
	m = key(m, tea.KeyMsg{Type: tea.KeyEsc})
	if m.mode != modeRead {
		t.Fatalf("esc did not return to reading (mode=%v)", m.mode)
	}
	if m.currentChapter() != 21 {
		t.Errorf("esc changed chapter to %d want 21", m.currentChapter())
	}
}

func TestReaderRemembersPlace(t *testing.T) {
	// Persisting/restoring a reading position needs real verses (savePlace
	// no-ops when len(verses)==0); the reader's first version is wuj, so the
	// optional wuj corpus must be embedded.
	requireCorpus(t, "wuj")
	dir := t.TempDir()
	t.Setenv("XDG_DATA_HOME", dir)
	tbl, _ := bible.LoadBookTable(nil)
	cfg := config.Default()
	cfg.UILanguage = "en"
	cfg.SiglaStyle = "english"
	cfg.Versions = []string{"wuj", "vul", "grb", "drb"}

	m := NewReader(cfg, tbl, bookmarks.Open())
	m = win(m, 80, 24)
	m = key(m, runes("jn"))
	m = key(m, tea.KeyMsg{Type: tea.KeyEnter}) // John 1 (openBook saves place)
	m = key(m, runes("n"))                     // -> John 2 (chapterStep saves place)

	m2 := NewReader(cfg, tbl, bookmarks.Open())
	if m2.mode != modeRead {
		t.Fatalf("did not restore reading mode")
	}
	if m2.books[m2.bookIdx].Canonical != "John" {
		t.Errorf("restored book = %q want John", m2.books[m2.bookIdx].Canonical)
	}
	if m2.currentChapter() != 2 {
		t.Errorf("restored chapter = %d want 2", m2.currentChapter())
	}
}