package beads

import (
	"context"
	"errors"
	"sort"
	"strings"

	"sourcecraft.dev/bigbes/sr-ht-dolt/browse"
)

// --- helpers -----------------------------------------------------------------

// readRows reads up to Max rows of a required table and its reported total.
func readRows(ctx context.Context, sess BrowseSession, ref, table string) (*browse.RowPage, int, error) {
	page, err := sess.Rows(ctx, ref, table, 0, Max)
	if err != nil {
		return nil, 0, err
	}
	return page, page.Total, nil
}

// readRowsOptional is readRows for a table that may not exist: ErrTableNotFound
// degrades to (nil, 0, nil) so the caller can treat it as empty.
func readRowsOptional(ctx context.Context, sess BrowseSession, ref, table string) (*browse.RowPage, int, error) {
	page, err := sess.Rows(ctx, ref, table, 0, Max)
	if err != nil {
		if errors.Is(err, browse.ErrTableNotFound) {
			return nil, 0, nil
		}
		return nil, 0, err
	}
	return page, page.Total, nil
}

// indexCols builds a column-name → cell-index map from a RowPage's Columns, so
// cells are addressed by name regardless of the underlying column order.
func indexCols(cols []string) map[string]int {
	m := make(map[string]int, len(cols))
	for i, c := range cols {
		m[c] = i
	}
	return m
}

// cell returns the named column's value for a row, or "" when the column is
// absent, out of range, or the literal browse NULL placeholder.
func cell(cols map[string]int, row []string, name string) string {
	i, ok := cols[name]
	if !ok || i < 0 || i >= len(row) {
		return ""
	}
	v := row[i]
	if v == "NULL" {
		return ""
	}
	return v
}

// truthy reports whether a cell reads as a set boolean/flag.
func truthy(s string) bool {
	switch strings.ToLower(strings.TrimSpace(s)) {
	case "1", "true", "yes", "t", "y":
		return true
	}
	return false
}

// sortedKeys returns a set's keys in ascending order.
func sortedKeys(set map[string]bool) []string {
	out := make([]string, 0, len(set))
	for k := range set {
		out = append(out, k)
	}
	sort.Strings(out)
	return out
}

// containsString reports whether s is in xs.
func containsString(xs []string, s string) bool {
	for _, x := range xs {
		if x == s {
			return true
		}
	}
	return false
}