package sqlite

import (
	"database/sql"
	"path/filepath"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"git.warky.dev/wdevs/relspecgo/pkg/readers"
)

func TestParseGeneratedExpression(t *testing.T) {
	createSQL := `CREATE TABLE people (
		id INTEGER PRIMARY KEY,
		"first" TEXT,
		last TEXT,
		full_name TEXT GENERATED ALWAYS AS (coalesce("first", '') || ' ' || last) STORED,
		initials TEXT AS (substr("first", 1, 1) || substr(last, 1, 1)),
		plain TEXT NOT NULL
	)`

	tests := []struct {
		column string
		want   string
	}{
		{"full_name", `coalesce("first", '') || ' ' || last`},
		{"initials", `substr("first", 1, 1) || substr(last, 1, 1)`},
		{"plain", ""},
		{"missing", ""},
	}
	for _, tt := range tests {
		t.Run(tt.column, func(t *testing.T) {
			assert.Equal(t, tt.want, parseGeneratedExpression(createSQL, tt.column))
		})
	}
}

func TestReader_GeneratedColumns(t *testing.T) {
	dbPath := filepath.Join(t.TempDir(), "gen.db")
	db, err := sql.Open("sqlite", dbPath)
	require.NoError(t, err)
	_, err = db.Exec(`CREATE TABLE people (
		id INTEGER PRIMARY KEY,
		first TEXT,
		last TEXT,
		full_name TEXT GENERATED ALWAYS AS (first || ' ' || last) STORED,
		initials TEXT AS (substr(first, 1, 1) || substr(last, 1, 1))
	)`)
	require.NoError(t, err)
	require.NoError(t, db.Close())

	got, err := NewReader(&readers.ReaderOptions{FilePath: dbPath}).ReadDatabase()
	require.NoError(t, err)

	cols := got.Schemas[0].Tables[0].Columns
	require.Contains(t, cols, "full_name", "generated columns must be read")
	assert.True(t, cols["full_name"].Generated)
	assert.Equal(t, "first || ' ' || last", cols["full_name"].GenerationExpression)
	assert.True(t, cols["initials"].Generated)
	assert.Equal(t, "substr(first, 1, 1) || substr(last, 1, 1)", cols["initials"].GenerationExpression)
	assert.False(t, cols["first"].Generated)
}