// backend\milestone_inventory.go

package main

import (
	"context"
	"strings"
	"unicode"

	"github.com/jackc/pgx/v5"
)

func normalizeMilestoneManufacturer(value string, model string) string {
	value = strings.TrimSpace(value)
	if value == "" {
		return ""
	}

	model = strings.TrimSpace(model)
	normalizedValue := strings.ToLower(value)

	if strings.EqualFold(value, model) ||
		strings.HasSuffix(normalizedValue, " device") ||
		strings.Contains(normalizedValue, " camera") ||
		strings.Contains(normalizedValue, " encoder") ||
		strings.Contains(normalizedValue, " video") {
		if manufacturer := extractMilestoneManufacturerFromName(value); manufacturer != "" {
			return manufacturer
		}
	}

	return value
}

func extractMilestoneManufacturerFromName(value string) string {
	value = strings.TrimSpace(value)
	if value == "" {
		return ""
	}

	parts := strings.FieldsFunc(value, func(r rune) bool {
		return unicode.IsSpace(r) ||
			r == '_' ||
			r == '-' ||
			r == '/' ||
			r == '\\' ||
			r == '(' ||
			r == ')' ||
			r == ','
	})

	ignoredWords := map[string]bool{
		"device":   true,
		"camera":   true,
		"video":    true,
		"encoder":  true,
		"ip":       true,
		"network":  true,
		"hardware": true,
	}

	for _, part := range parts {
		part = strings.TrimSpace(part)

		if part == "" {
			continue
		}

		if isOnlyDigits(part) {
			continue
		}

		if ignoredWords[strings.ToLower(part)] {
			continue
		}

		return part
	}

	return ""
}

func buildMilestoneInventoryNumber(
	ctx context.Context,
	tx pgx.Tx,
	hardwareDevice milestoneHardwareDevice,
) (string, error) {
	inventoryNumber := extractInventoryNumberFromMilestoneDeviceName(
		hardwareDevice.DeviceName,
	)

	if inventoryNumber == "" {
		inventoryNumber = extractInventoryNumberFromMilestoneDeviceName(
			hardwareDevice.DisplayName,
		)
	}

	if inventoryNumber == "" {
		inventoryNumber = buildGeneratedMilestoneInventoryNumber(
			hardwareDevice.HardwareID,
		)
	}

	var exists bool

	err := tx.QueryRow(
		ctx,
		`
		SELECT EXISTS(
			SELECT 1
			FROM devices
			WHERE lower(inventory_number) = lower($1)
			  AND milestone_hardware_id <> $2
		)
		`,
		inventoryNumber,
		hardwareDevice.HardwareID,
	).Scan(&exists)
	if err != nil {
		return "", err
	}

	if !exists {
		return inventoryNumber, nil
	}

	suffix := strings.ToUpper(strings.ReplaceAll(strings.TrimSpace(hardwareDevice.HardwareID), "-", ""))
	if len(suffix) > 8 {
		suffix = suffix[:8]
	}

	if suffix == "" {
		suffix = "MS"
	}

	return inventoryNumber + "-" + suffix, nil
}

func extractInventoryNumberFromMilestoneDeviceName(value string) string {
	value = strings.TrimSpace(value)
	if value == "" {
		return ""
	}

	parts := strings.FieldsFunc(value, func(r rune) bool {
		return r == '_' || r == '-' || unicode.IsSpace(r)
	})

	for _, part := range parts {
		part = strings.TrimSpace(part)

		if part == "" {
			continue
		}

		if isOnlyDigits(part) {
			return part
		}
	}

	return ""
}

func isOnlyDigits(value string) bool {
	if value == "" {
		return false
	}

	for _, r := range value {
		if r < '0' || r > '9' {
			return false
		}
	}

	return true
}

func buildGeneratedMilestoneInventoryNumber(hardwareID string) string {
	value := strings.ToUpper(strings.ReplaceAll(strings.TrimSpace(hardwareID), "-", ""))

	if len(value) > 12 {
		value = value[:12]
	}

	if value == "" {
		value = "UNKNOWN"
	}

	return "MS-" + value
}