package tui

import (
	"path/filepath"
	"strings"
	"testing"

	tea "github.com/charmbracelet/bubbletea"

	"git.petrovv.com/nikola/money/internal/config"
	"git.petrovv.com/nikola/money/internal/model"
	"git.petrovv.com/nikola/money/internal/rules"
	"git.petrovv.com/nikola/money/internal/store"
)

// newTestModel builds a model over an index holding two transactions, one of
// which the rules tag as groceries.
func newTestModel(t *testing.T) (*Model, *store.DB) {
	t.Helper()

	db, err := store.Open(filepath.Join(t.TempDir(), "index.db"))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { db.Close() })

	accountID, err := db.UpsertAccount(model.Account{
		Slug: "checking", Name: "Checking", Currency: "EUR", MinorDigits: 2,
	})
	if err != nil {
		t.Fatal(err)
	}
	sourceID, err := db.SourceFile(accountID, "checking/st.csv", "sha", "2026-01-01T00:00:00Z")
	if err != nil {
		t.Fatal(err)
	}
	for i, d := range []string{"LIDL SOFIA", "SOME RANDOM SHOP"} {
		if _, err := db.InsertTransaction(model.Transaction{
			AccountID:    accountID,
			SourceFileID: sourceID,
			Fingerprint:  d,
			Date:         "2026-01-0" + string(rune('1'+i)),
			Description:  d,
			AmountMinor:  -1000,
		}); err != nil {
			t.Fatal(err)
		}
	}

	engine := rules.New(&config.Rules{Rule: []config.Rule{{Match: "*LIDL*", Tag: "groceries"}}})
	if _, err := engine.Retag(db); err != nil {
		t.Fatal(err)
	}

	m := New(t.TempDir(), db, nil, engine)
	if err := m.reload(); err != nil {
		t.Fatal(err)
	}
	m.Update(tea.WindowSizeMsg{Width: 120, Height: 30})
	return m, db
}

// key sends a single keypress to the model.
func key(t *testing.T, m *Model, s string) {
	t.Helper()
	var msg tea.KeyMsg
	switch s {
	case "enter":
		msg = tea.KeyMsg{Type: tea.KeyEnter}
	case "esc":
		msg = tea.KeyMsg{Type: tea.KeyEsc}
	default:
		msg = tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune(s)}
	}
	m.Update(msg)
	if m.err != nil {
		t.Fatalf("key %q produced an error: %v", s, m.err)
	}
}

// typeText sends each character as its own keypress, as a terminal would.
func typeText(t *testing.T, m *Model, s string) {
	t.Helper()
	for _, r := range s {
		m.Update(tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{r}})
	}
}

// cursorTo moves the transaction cursor onto the row with the given description.
func cursorTo(t *testing.T, m *Model, desc string) {
	t.Helper()
	for i, txn := range m.txns {
		if txn.Description == desc {
			m.txnTable.SetCursor(i)
			return
		}
	}
	t.Fatalf("no visible transaction with description %q", desc)
}

func TestTagFlow(t *testing.T) {
	m, db := newTestModel(t)

	key(t, m, "2") // transactions view
	cursorTo(t, m, "SOME RANDOM SHOP")

	key(t, m, "t") // open the tag prompt
	if m.input != inputTag {
		t.Fatal("expected the tag prompt to open")
	}
	typeText(t, m, "hobby")
	key(t, m, "enter")

	if m.input != inputNone {
		t.Error("expected the prompt to close after enter")
	}

	txns, err := db.Transactions(store.Filter{})
	if err != nil {
		t.Fatal(err)
	}
	var found bool
	for _, txn := range txns {
		if txn.Description == "SOME RANDOM SHOP" {
			found = true
			if txn.ManualTag != "hobby" {
				t.Errorf("manual_tag = %q, want %q", txn.ManualTag, "hobby")
			}
		}
	}
	if !found {
		t.Fatal("transaction disappeared after tagging")
	}

	// The tag column marks manual overrides with a trailing asterisk.
	if !strings.Contains(m.View(), "hobby*") {
		t.Error("expected the tagged row to render with a manual-override marker")
	}
}

func TestTagPromptCancel(t *testing.T) {
	m, db := newTestModel(t)
	key(t, m, "2")
	cursorTo(t, m, "SOME RANDOM SHOP")

	key(t, m, "t")
	typeText(t, m, "nope")
	key(t, m, "esc")

	if m.input != inputNone {
		t.Error("expected esc to close the prompt")
	}
	txns, _ := db.Transactions(store.Filter{Untagged: true})
	if len(txns) != 1 {
		t.Errorf("esc should not have tagged anything; untagged count = %d, want 1", len(txns))
	}
}

func TestTransferToggleAndClear(t *testing.T) {
	m, db := newTestModel(t)
	key(t, m, "2")
	cursorTo(t, m, "LIDL SOFIA")

	key(t, m, "x")
	txn := findTxn(t, db, "LIDL SOFIA")
	if !txn.IsTransfer() {
		t.Error("expected x to mark the row as a transfer")
	}

	key(t, m, "x")
	if findTxn(t, db, "LIDL SOFIA").IsTransfer() {
		t.Error("expected a second x to unmark it")
	}

	// c drops the manual override, restoring the rule's verdict.
	key(t, m, "c")
	txn = findTxn(t, db, "LIDL SOFIA")
	if txn.ManualTransfer != nil || txn.ManualTag != "" {
		t.Errorf("expected c to clear overrides, got manual tag %q transfer %v", txn.ManualTag, txn.ManualTransfer)
	}
	if txn.Tag() != "groceries" {
		t.Errorf("tag after clearing = %q, want groceries from the rule", txn.Tag())
	}
}

func TestUntaggedToggle(t *testing.T) {
	m, _ := newTestModel(t)

	key(t, m, "u")
	if !m.onlyUntagged {
		t.Fatal("expected u to enable the untagged filter")
	}
	if len(m.txns) != 1 || m.txns[0].Description != "SOME RANDOM SHOP" {
		t.Fatalf("untagged view shows %+v, want only SOME RANDOM SHOP", m.txns)
	}

	// Tagging the last untagged row empties the view; the cursor must stay valid.
	cursorTo(t, m, "SOME RANDOM SHOP")
	key(t, m, "t")
	typeText(t, m, "hobby")
	key(t, m, "enter")
	if len(m.txns) != 0 {
		t.Errorf("expected the untagged view to be empty, got %d rows", len(m.txns))
	}
	if _, ok := m.selected(); ok {
		t.Error("expected no selection in an empty view")
	}
	m.View() // must not panic on an empty table

	key(t, m, "u")
	if len(m.txns) != 2 {
		t.Errorf("expected all rows back after toggling off, got %d", len(m.txns))
	}
}

func TestSearchFilter(t *testing.T) {
	m, _ := newTestModel(t)

	key(t, m, "/")
	if m.input != inputSearch {
		t.Fatal("expected the search prompt to open")
	}
	typeText(t, m, "lidl")
	key(t, m, "enter")

	if len(m.txns) != 1 || m.txns[0].Description != "LIDL SOFIA" {
		t.Fatalf("search results = %+v, want only LIDL SOFIA", m.txns)
	}

	// Reopening the prompt pre-fills the active query so it can be edited.
	key(t, m, "/")
	if got := m.text.Value(); got != "lidl" {
		t.Errorf("search prompt pre-filled with %q, want %q", got, "lidl")
	}
	for range len("lidl") {
		m.Update(tea.KeyMsg{Type: tea.KeyBackspace})
	}
	key(t, m, "enter") // an emptied query clears the filter
	if len(m.txns) != 2 {
		t.Errorf("expected the filter to clear, got %d rows", len(m.txns))
	}
}

func TestReportViewExcludesTransfers(t *testing.T) {
	m, _ := newTestModel(t)
	key(t, m, "2")
	cursorTo(t, m, "LIDL SOFIA")
	key(t, m, "x") // mark as a transfer

	key(t, m, "3") // report view
	view := m.View()
	if strings.Contains(view, "groceries") {
		t.Error("a transfer must not appear in the report")
	}
	if !strings.Contains(view, "TOTAL") {
		t.Error("expected a TOTAL row in the report")
	}
}

// newEmptyModel builds a model over an index with nothing in it.
func newEmptyModel(t *testing.T, accounts []*config.Account) *Model {
	t.Helper()
	db, err := store.Open(filepath.Join(t.TempDir(), "index.db"))
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { db.Close() })

	m := New("/data/root", db, accounts, rules.New(&config.Rules{}))
	if err := m.reload(); err != nil {
		t.Fatal(err)
	}
	m.Update(tea.WindowSizeMsg{Width: 120, Height: 30})
	return m
}

// Configured but never imported is the confusing case: the folders exist on
// disk, but nothing is registered in the index until an import runs.
func TestEmptyAccountsWithConfiguredFolders(t *testing.T) {
	m := newEmptyModel(t, []*config.Account{
		{Slug: "checking", Currency: "EUR", Parser: "csv"},
		{Slug: "savings", Currency: "EUR", Parser: "csv"},
	})

	view := m.View()
	for _, want := range []string{"No accounts imported yet", "2 account folder(s)", "/data/root", "Press i to import"} {
		if !strings.Contains(view, want) {
			t.Errorf("accounts view missing %q:\n%s", want, view)
		}
	}
}

func TestEmptyAccountsWithNoFolders(t *testing.T) {
	m := newEmptyModel(t, nil)

	view := m.View()
	for _, want := range []string{"No account folders found", "/data/root", "account.toml"} {
		if !strings.Contains(view, want) {
			t.Errorf("accounts view missing %q:\n%s", want, view)
		}
	}
}

func TestEmptyTransactionsMessages(t *testing.T) {
	m := newEmptyModel(t, nil)
	key(t, m, "2")

	if view := m.View(); !strings.Contains(view, "No transactions yet") {
		t.Errorf("expected an empty-transactions message:\n%s", view)
	}

	// Each way of emptying the view explains itself differently.
	m.filter.AccountSlug = "checking"
	if err := m.reloadTxns(); err != nil {
		t.Fatal(err)
	}
	if view := m.View(); !strings.Contains(view, "No transactions in checking") {
		t.Errorf("expected an account-scoped message:\n%s", view)
	}

	m.filter.AccountSlug = ""
	m.filter.Search = "lidl"
	if err := m.reloadTxns(); err != nil {
		t.Fatal(err)
	}
	if view := m.View(); !strings.Contains(view, "No transactions match /lidl") {
		t.Errorf("expected a search message:\n%s", view)
	}

	m.filter.Search = ""
	m.onlyUntagged = true
	if err := m.reloadTxns(); err != nil {
		t.Fatal(err)
	}
	if view := m.View(); !strings.Contains(view, "Nothing untagged") {
		t.Errorf("expected an untagged message:\n%s", view)
	}
}

func TestEmptyReportMessage(t *testing.T) {
	m := newEmptyModel(t, nil)
	key(t, m, "3")
	if view := m.View(); !strings.Contains(view, "Nothing to report yet") {
		t.Errorf("expected an empty-report message:\n%s", view)
	}
}

// With data present, the tables render instead of the empty-state text.
func TestNoEmptyMessageWhenPopulated(t *testing.T) {
	m, _ := newTestModel(t)
	for _, k := range []string{"1", "2", "3"} {
		key(t, m, k)
		if got := m.emptyMessage(); got != "" {
			t.Errorf("view %s showed an empty message with data present: %q", k, got)
		}
	}
	key(t, m, "2")
	if !strings.Contains(m.View(), "LIDL SOFIA") {
		t.Error("expected the transactions table to render")
	}
}

func findTxn(t *testing.T, db *store.DB, desc string) model.Transaction {
	t.Helper()
	txns, err := db.Transactions(store.Filter{})
	if err != nil {
		t.Fatal(err)
	}
	for _, txn := range txns {
		if txn.Description == desc {
			return txn
		}
	}
	t.Fatalf("no transaction with description %q", desc)
	return model.Transaction{}
}