package cursor

import (
	"strings"
	"testing"
	"time"

	"github.com/go-jet/jet/v2/mysql"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestTimestampValue(t *testing.T) {
	assert := assert.New(t)

	RegisterColumn(Meeting.StartTime)

	when := time.Date(2026, 3, 15, 14, 30, 0, 0, time.UTC)
	v := NewTimestampValue(when, Meeting.StartTime)
	assert.Equal(when, v.Val)
	assert.Equal(Meeting.StartTime, v.Col())
	assert.False(v.IsEmpty())
	assert.True(NewTimestampValue(time.Time{}, Meeting.StartTime).IsEmpty())
}

func TestMeetingCompositeCursor(t *testing.T) {
	assert := assert.New(t)
	registerMeetingCursorColumns(t)

	when := time.Date(2026, 6, 1, 9, 0, 0, 0, time.UTC)
	base := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderDescending,
	)
	cursor := base.CopyWithVals(
		NewStringValue("meeting-uuid-1", Meeting.ID),
		NewTimestampValue(when, Meeting.StartTime),
	)

	assert.Equal(NewColumnKey(Meeting.ID), cursor.Index.ColumnKey())
	assert.Equal(NewColumnKey(Meeting.StartTime), cursor.OrderColumnKey)
	assert.True(cursor.IsComposite())
	assert.False(cursor.IsEmpty())

	encoded, err := cursor.Encode()
	require.NoError(t, err)
	assert.Contains(encoded, `"order_val"`)
	assert.Contains(encoded, `"start_time"`)

	decoded := NewCursor(NewStringValue("", Meeting.ID), Meeting.StartTime, OrderDescending)
	require.NoError(t, decoded.Decode(encoded))
	assert.True(decoded.IsComposite())
	assert.Equal("meeting-uuid-1", decoded.Index.(*StringValue).Val)
	assert.Equal(when, decoded.GenericOrderValue().(*TimestampValue).Val)
}

func TestMeetingCursorWithoutOrderValueIsNotComposite(t *testing.T) {
	assert := assert.New(t)
	registerMeetingCursorColumns(t)

	cursor := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderDescending,
	)

	assert.False(cursor.IsComposite())
}

func TestMeetingCursorUsesTupleOrdering(t *testing.T) {
	assert := assert.New(t)
	registerMeetingCursorColumns(t)

	cursor := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderDescending,
	)

	assert.True(cursor.UsesTupleOrdering())
	assert.False(cursor.IsComposite())
}

func TestPaginateCompositeDESC(t *testing.T) {
	assert := assert.New(t)
	registerMeetingCursorColumns(t)

	when := time.Date(2026, 6, 1, 9, 0, 0, 0, time.UTC)
	cursor := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderDescending,
	).CopyWithVals(
		NewStringValue("meeting-uuid-1", Meeting.ID),
		NewTimestampValue(when, Meeting.StartTime),
	)

	stmt := mysqlSELECTWhere(PaginateConds(cursor))
	sql := stmt.DebugSql()

	assert.Contains(sql, "(meeting.start_time, meeting.id) < ('")
}

func TestPaginateCompositeASC(t *testing.T) {
	assert := assert.New(t)
	registerMeetingCursorColumns(t)

	when := time.Date(2026, 6, 1, 9, 0, 0, 0, time.UTC)
	cursor := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderAscending,
	).CopyWithVals(
		NewStringValue("meeting-uuid-1", Meeting.ID),
		NewTimestampValue(when, Meeting.StartTime),
	)

	stmt := mysqlSELECTWhere(PaginateConds(cursor))
	sql := stmt.DebugSql()

	assert.Contains(sql, "(meeting.start_time, meeting.id) > ('")
}

func TestOrderByClausesComposite(t *testing.T) {
	assert := assert.New(t)
	registerMeetingCursorColumns(t)

	when := time.Date(2026, 6, 1, 9, 0, 0, 0, time.UTC)
	cursor := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderDescending,
	).CopyWithVals(
		NewStringValue("meeting-uuid-1", Meeting.ID),
		NewTimestampValue(when, Meeting.StartTime),
	)

	clauses := OrderByClauses(cursor)
	require.Len(t, clauses, 2)

	stmt := Meeting.SELECT(Meeting.AllColumns).ORDER_BY(clauses...)
	sql := stmt.DebugSql()
	assert.True(
		strings.Contains(sql, "start_time DESC") && strings.Contains(sql, "id DESC"),
		"expected composite order by, got: %s", sql,
	)
}

func TestOrderByClausesTupleOrderingDefaultCursor(t *testing.T) {
	assert := assert.New(t)
	registerMeetingCursorColumns(t)

	cursor := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderDescending,
	)

	assert.True(cursor.UsesTupleOrdering())
	assert.False(cursor.IsComposite())

	clauses := OrderByClauses(cursor)
	require.Len(t, clauses, 2)

	stmt := Meeting.SELECT(Meeting.AllColumns).ORDER_BY(clauses...)
	sql := stmt.DebugSql()
	assert.True(
		strings.Contains(sql, "start_time DESC") && strings.Contains(sql, "id DESC"),
		"expected tuple order by on default cursor, got: %s", sql,
	)
}

func TestOrderByClausesNil(t *testing.T) {
	assert.Nil(t, OrderByClauses(nil))
}

func TestOrderByClausesSingleColumnASC(t *testing.T) {
	RegisterColumn(User.ID)

	cursor := NewCursor(NewInt64Value(1, User.ID), User.ID, OrderAscending)
	clauses := OrderByClauses(cursor)
	require.Len(t, clauses, 1)

	stmt := User.SELECT(User.AllColumns).ORDER_BY(clauses...)
	sql := stmt.DebugSql()
	assert.Contains(t, sql, "id ASC")
}

func TestPaginateValueTypes(t *testing.T) {
	RegisterColumn(User.ID, Meeting.StartTime)

	tests := []struct {
		name       string
		cond       mysql.BoolExpression
		wantSubstr string
	}{
		{
			name: "int64 desc",
			cond: PaginateConds(NewCursor(
				NewInt64Value(10, User.ID),
				User.ID,
				OrderDescending,
			)),
			wantSubstr: "user.id < 10",
		},
		{
			name: "int64 asc",
			cond: PaginateConds(NewCursor(
				NewInt64Value(10, User.ID),
				User.ID,
				OrderAscending,
			)),
			wantSubstr: "user.id > 10",
		},
		{
			name: "uint64 desc",
			cond: PaginateConds(NewCursor(
				NewUint64Value(10, User.ID),
				User.ID,
				OrderDescending,
			)),
			wantSubstr: "user.id < 10",
		},
		{
			name: "timestamp desc",
			cond: PaginateConds(NewCursor(
				NewTimestampValue(time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC), Meeting.StartTime),
				Meeting.StartTime,
				OrderDescending,
			)),
			wantSubstr: "meeting.start_time <",
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			sql := User.SELECT(User.AllColumns).WHERE(tc.cond).DebugSql()
			assert.Contains(t, sql, tc.wantSubstr)
		})
	}
}

func TestQueryCountCompositeSQL(t *testing.T) {
	assert := assert.New(t)
	registerMeetingCursorColumns(t)

	when := time.Date(2026, 6, 1, 9, 0, 0, 0, time.UTC)
	start := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderDescending,
	).CopyWithVals(
		NewStringValue("meeting-uuid-1", Meeting.ID),
		NewTimestampValue(when, Meeting.StartTime),
	)
	end := start.CopyWithVals(
		NewStringValue("meeting-uuid-2", Meeting.ID),
		NewTimestampValue(when, Meeting.StartTime),
	)

	stmt := Meeting.SELECT(
		mysql.COUNT(countBoundExpr(start, ">")).AS("before"),
		mysql.COUNT(countBoundExpr(end, "<")).AS("after"),
	).WHERE(mysql.Bool(true))
	sql := stmt.DebugSql()

	assert.Contains(sql, "IF((meeting.start_time, meeting.id) > ('")
	assert.Contains(sql, "IF((meeting.start_time, meeting.id) < ('")
}

func TestCountBoundExprSimple(t *testing.T) {
	RegisterColumn(MeetingRoom.ID)

	cursor := NewCursor(
		NewStringValue("room-1", MeetingRoom.ID),
		MeetingRoom.ID,
		OrderDescending,
	)

	stmt := MeetingRoom.SELECT(
		mysql.COUNT(countBoundExpr(cursor, "<")).AS("after"),
	).WHERE(mysql.Bool(true))
	sql := stmt.DebugSql()

	assert.Contains(t, sql, "IF(meeting_room.id < 'room-1', 1, NULL)")
}

func TestBuildQueryCountFn(t *testing.T) {
	registerMeetingCursorColumns(t)

	fn := BuildQueryCountFn(Meeting.ID, Meeting, mysql.Bool(true))
	require.NotNil(t, fn)

	when := time.Date(2026, 6, 1, 9, 0, 0, 0, time.UTC)
	start := NewCursor(
		NewStringValue("", Meeting.ID),
		Meeting.StartTime,
		OrderDescending,
	).CopyWithVals(
		NewStringValue("meeting-uuid-1", Meeting.ID),
		NewTimestampValue(when, Meeting.StartTime),
	)

	// Verify the returned fn builds the same SQL shape as QueryCount would.
	stmt := Meeting.SELECT(
		mysql.COUNT(Meeting.ID).AS("QueryCountResult.Total"),
		mysql.COUNT(countBoundExpr(start, ">")).AS("QueryCountResult.Before"),
		mysql.COUNT(countBoundExpr(start, "<")).AS("QueryCountResult.After"),
	).WHERE(mysql.Bool(true))
	sql := stmt.DebugSql()
	assert.Contains(t, sql, "COUNT(meeting.id)")
	assert.Contains(t, sql, "IF((meeting.start_time, meeting.id) >")
}