package cursor

import (
	"errors"
	"strings"
	"testing"
	"time"

	"gitea.auvem.com/go-toolkit/dbx"
	"github.com/go-jet/jet/v2/mysql"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestConnectionFromRelayArgs(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)
	RegisterColumn(User.ID)

	newZero := func() *Cursor[mysql.IntegerExpression, mysql.ColumnInteger] {
		return NewCursor(NewInt64Value(0, User.ID), User.ID, OrderDescending)
	}

	var gotCursor *Cursor[mysql.IntegerExpression, mysql.ColumnInteger]
	var gotLimit int

	list := func(c *Cursor[mysql.IntegerExpression, mysql.ColumnInteger], limit int) (*Connection[int], error) {
		gotCursor = c
		gotLimit = limit
		return &Connection[int]{}, nil
	}

	conn, err := ConnectionFromRelayArgs(nil, nil, newZero, list)
	require.NoError(err)
	require.NotNil(conn)
	assert.Nil(gotCursor)
	assert.Equal(0, gotLimit)

	first := 25
	conn, err = ConnectionFromRelayArgs(nil, &first, newZero, list)
	require.NoError(err)
	require.NotNil(conn)
	assert.Nil(gotCursor)
	assert.Equal(25, gotLimit)

	encoded, err := NewCursor(
		NewInt64Value(7, User.ID),
		User.ID,
		OrderDescending,
	).Encode()
	require.NoError(err)

	conn, err = ConnectionFromRelayArgs(&encoded, &first, newZero, list)
	require.NoError(err)
	require.NotNil(conn)
	require.NotNil(gotCursor)
	assert.Equal(int64(7), gotCursor.Index.(*Int64Value).Val)
	assert.Equal(25, gotLimit)

	bad := "{not-json"
	_, err = ConnectionFromRelayArgs(&bad, nil, newZero, list)
	require.Error(err)

	listErr := errors.New("list failed")
	_, err = ConnectionFromRelayArgs(nil, nil, newZero, func(*Cursor[mysql.IntegerExpression, mysql.ColumnInteger], int) (*Connection[int], error) {
		return nil, listErr
	})
	require.ErrorIs(err, listErr)
}

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

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

	stmt := mysql.SELECT(Meeting.AllColumns).FROM(Meeting)
	stmt.WHERE(mysql.Bool(true).AND(PaginateConds(active)))
	stmt.ORDER_BY(OrderByClauses(active)...)
	sql := stmt.DebugSql()

	assert.Contains(sql, "(meeting.start_time, meeting.id) < ('")
	assert.True(
		strings.Contains(sql, "start_time DESC") && strings.Contains(sql, "id DESC"),
		"expected composite order by, got: %s", sql,
	)
}

func TestPageQueryRunSQLSimple(t *testing.T) {
	assert := assert.New(t)
	RegisterColumn(MeetingRoom.ID)

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

	stmt := mysql.SELECT(MeetingRoom.AllColumns).FROM(MeetingRoom)
	stmt.WHERE(mysql.Bool(true).AND(PaginateStringConds(active)))
	stmt.ORDER_BY(OrderByClauses(active)...)
	sql := stmt.DebugSql()

	assert.Contains(sql, "meeting_room.id < 'room-1'")
	assert.Contains(sql, "id DESC")
}

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

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

	var nilCursor *Cursor[mysql.StringExpression, mysql.ColumnString]
	stmt := mysql.SELECT(Meeting.AllColumns).FROM(Meeting)
	stmt.WHERE(mysql.Bool(true).AND(PaginateConds(nilCursor)))
	stmt.ORDER_BY(OrderByClauses(defaultCursor)...)
	sql := stmt.DebugSql()

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

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

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

	stmt := mysql.SELECT(Meeting.AllColumns).FROM(Meeting)
	stmt.WHERE(mysql.Bool(true).AND(PaginateConds(defaultCursor)))
	stmt.ORDER_BY(OrderByClauses(defaultCursor)...)
	sql := stmt.DebugSql()

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

func TestPageQueryRunSQLFirstPageRoomDefaultCursor(t *testing.T) {
	assert := assert.New(t)
	RegisterColumn(MeetingRoom.ID)

	defaultCursor := NewCursor(
		NewStringValue("", MeetingRoom.ID),
		MeetingRoom.ID,
		OrderDescending,
	)

	stmt := mysql.SELECT(MeetingRoom.AllColumns).FROM(MeetingRoom)
	stmt.WHERE(mysql.Bool(true).AND(PaginateStringConds(defaultCursor)))
	stmt.ORDER_BY(OrderByClauses(defaultCursor)...)
	sql := stmt.DebugSql()

	assert.NotContains(sql, "meeting_room.id < ''")
	assert.Contains(sql, "id DESC")
}

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

	type row struct {
		ID int64
	}

	defaultCursor := func() *Cursor[mysql.IntegerExpression, mysql.ColumnInteger] {
		return NewCursor(NewInt64Value(0, User.ID), User.ID, OrderDescending)
	}

	items := []*row{{ID: 1}, {ID: 2}}
	scanErr := errors.New("scan failed")
	afterScanErr := errors.New("after scan failed")

	t.Run("success with default cursor and after scan", func(t *testing.T) {
		var scannedStmt mysql.SelectStatement
		q := PageQuery[row, mysql.IntegerExpression, mysql.ColumnInteger]{
			Stmt:  User.SELECT(User.AllColumns).FROM(User),
			Conds: mysql.Bool(true),
			Default: defaultCursor,
			Limit: 10,
			CountFn: func(_ dbx.Queryable, _, _ GenericCursor) (QueryCountResult, error) {
				return QueryCountResult{Total: 2, After: 1, Before: 0}, nil
			},
			Scan: func(stmt mysql.SelectStatement, dest *[]*row) error {
				scannedStmt = stmt
				*dest = items
				return nil
			},
			AfterScan: func(rows []*row) ([]*row, error) {
				return rows[:1], nil
			},
			ToEdge: func(_ *Cursor[mysql.IntegerExpression, mysql.ColumnInteger], item *row) (GenericCursor, error) {
				return NewCursor(NewInt64Value(item.ID, User.ID), User.ID, OrderDescending), nil
			},
		}

		conn, err := q.Run()
		require.NoError(t, err)
		require.NotNil(t, conn)
		assert.Len(t, conn.Edges, 1)
		assert.True(t, conn.PageInfo.HasNextPage)
		assert.False(t, conn.PageInfo.HasPreviousPage)
		assert.Equal(t, 2, conn.TotalCount)
		assert.Contains(t, scannedStmt.DebugSql(), "LIMIT 10")
	})

	t.Run("scan error", func(t *testing.T) {
		q := PageQuery[row, mysql.IntegerExpression, mysql.ColumnInteger]{
			Stmt:    User.SELECT(User.AllColumns).FROM(User),
			Conds:   mysql.Bool(true),
			Default: defaultCursor,
			Scan: func(_ mysql.SelectStatement, _ *[]*row) error {
				return scanErr
			},
			ToEdge: func(_ *Cursor[mysql.IntegerExpression, mysql.ColumnInteger], item *row) (GenericCursor, error) {
				return NewCursor(NewInt64Value(item.ID, User.ID), User.ID, OrderDescending), nil
			},
		}
		_, err := q.Run()
		require.Error(t, err)
		assert.Contains(t, err.Error(), "failed to run paginated query")
	})

	t.Run("after scan error", func(t *testing.T) {
		q := PageQuery[row, mysql.IntegerExpression, mysql.ColumnInteger]{
			Stmt:    User.SELECT(User.AllColumns).FROM(User),
			Conds:   mysql.Bool(true),
			Default: defaultCursor,
			Scan: func(_ mysql.SelectStatement, dest *[]*row) error {
				*dest = items
				return nil
			},
			AfterScan: func(_ []*row) ([]*row, error) {
				return nil, afterScanErr
			},
			ToEdge: func(_ *Cursor[mysql.IntegerExpression, mysql.ColumnInteger], item *row) (GenericCursor, error) {
				return NewCursor(NewInt64Value(item.ID, User.ID), User.ID, OrderDescending), nil
			},
		}
		_, err := q.Run()
		require.ErrorIs(t, err, afterScanErr)
	})
}