package excel

import (
	"fmt"
	"strings"
)

func ValidateRequiredFields(rows []ParsedRow, specs []ColumnSpec) []RowIssue {
	issues := make([]RowIssue, 0)
	for _, row := range rows {
		for _, spec := range specs {
			if !spec.Required {
				continue
			}
			value := Field(row, spec.Name)
			if value != "" {
				continue
			}
			issues = append(issues, RowIssue{
				RowNo:   row.RowNo,
				Column:  spec.Name,
				Value:   value,
				Message: fmt.Sprintf("%s is required", spec.Name),
			})
		}
	}
	return issues
}

func ValidateRowTypes(rows []ParsedRow, specs []ColumnSpec) []RowIssue {
	issues := make([]RowIssue, 0)
	for _, row := range rows {
		for _, spec := range specs {
			value := Field(row, spec.Name)
			if value == "" {
				continue
			}
			if _, err := normalizedValue(value, spec.Type); err != nil {
				issues = append(issues, RowIssue{
					RowNo:   row.RowNo,
					Column:  spec.Name,
					Value:   value,
					Message: fmt.Sprintf("%s format is invalid", spec.Name),
				})
			}
		}
	}
	return issues
}

func ValidateFileConsistency(rows []ParsedRow, rules []ConsistencyRule) []RowIssue {
	issues := make([]RowIssue, 0)
	for _, rule := range rules {
		baseValue := ""
		baseSet := false
		for _, row := range rows {
			raw := Field(row, rule.Name)
			normalized := ""
			if strings.TrimSpace(raw) == "" {
				if !rule.AllowEmpty {
					issues = append(issues, RowIssue{
						RowNo:   row.RowNo,
						Column:  rule.Name,
						Value:   raw,
						Message: fmt.Sprintf("%s must not be empty", rule.Name),
					})
					continue
				}
			} else {
				value, err := normalizedValue(raw, rule.Type)
				if err != nil {
					issues = append(issues, RowIssue{
						RowNo:   row.RowNo,
						Column:  rule.Name,
						Value:   raw,
						Message: fmt.Sprintf("%s format is invalid", rule.Name),
					})
					continue
				}
				normalized = value
			}

			if !baseSet {
				baseValue = normalized
				baseSet = true
				continue
			}
			if normalized != baseValue {
				issues = append(issues, RowIssue{
					RowNo:   row.RowNo,
					Column:  rule.Name,
					Value:   raw,
					Message: fmt.Sprintf("%s must be consistent", rule.Name),
				})
			}
		}
	}
	return issues
}