package conga

import (
	"database/sql"
	"log/slog"
	"sort"
	"strings"
	"time"

	"git.golem15.com/golem15/summercms/modules/backpack"
	"github.com/riverqueue/river"
	"github.com/riverqueue/river/riverdriver/riverdatabasesql"
)

const (
	// defaultQueue is River's default queue name.
	defaultQueue = river.QueueDefault
	// defaultMaxAttempts matches the WinterCMS queue worker's --tries=3.
	defaultMaxAttempts = 3
	// defaultJobTimeout matches the WinterCMS queue worker's --timeout=300.
	defaultJobTimeout = 300 * time.Second
	// defaultMaxWorkers is the concurrency of a queue without configuration.
	defaultMaxWorkers = 4
)

// settings is the queue.* configuration of one app.
type settings struct {
	maxAttempts int
	jobTimeout  time.Duration
	queues      map[string]int
	workInServe bool
}

func settingsFromApp(app *backpack.App) settings {
	s := settings{
		maxAttempts: defaultMaxAttempts,
		jobTimeout:  defaultJobTimeout,
		queues:      map[string]int{},
		workInServe: true,
	}
	if app == nil || app.Config == nil {
		return s
	}
	c := app.Config
	if n := c.Int("queue.max_attempts"); n > 0 {
		s.maxAttempts = n
	}
	if raw := strings.TrimSpace(c.String("queue.job_timeout")); raw != "" {
		if d, err := time.ParseDuration(raw); err == nil && d > 0 {
			s.jobTimeout = d
		} else if n := c.Int("queue.job_timeout"); n > 0 {
			s.jobTimeout = time.Duration(n) * time.Second
		}
	}
	if c.Has("queue.work_in_serve") {
		s.workInServe = c.Bool("queue.work_in_serve")
	}
	if raw, ok := c.Lookup("queue.queues"); ok {
		if m, ok := raw.(map[string]any); ok {
			for name := range m {
				name = strings.TrimSpace(name)
				if name == "" {
					continue
				}
				n := c.Int("queue.queues." + name)
				if n <= 0 {
					n = defaultMaxWorkers
				}
				s.queues[name] = n
			}
		}
	}
	return s
}

// knownQueues is the configured queues plus every queue a registered job
// names plus default, each with its MaxWorkers.
func knownQueues(s settings, jobs map[string]congaJob) map[string]int {
	out := map[string]int{defaultQueue: defaultMaxWorkers}
	for _, j := range jobs {
		if q := j.config().queue; q != "" {
			out[q] = defaultMaxWorkers
		}
	}
	for name, n := range s.queues {
		out[name] = n
	}
	return out
}

func sortedQueueNames(queues map[string]int) []string {
	names := make([]string, 0, len(queues))
	for name := range queues {
		names = append(names, name)
	}
	sort.Strings(names)
	return names
}

// baseConfig is the River client configuration shared by the insert-only
// and worker clients. Queues and Workers are set by the worker only.
func baseConfig(s settings, log *slog.Logger) *river.Config {
	return &river.Config{
		MaxAttempts: s.maxAttempts,
		JobTimeout:  s.jobTimeout,
		Logger:      log,
	}
}

// newInsertClient builds an insert-only client on the shared pool. It is
// never started; it inserts, cancels and deletes jobs.
func newInsertClient(sqlDB *sql.DB, s settings, log *slog.Logger) (*river.Client[*sql.Tx], error) {
	return river.NewClient(riverdatabasesql.New(sqlDB), baseConfig(s, log))
}

func loggerFromApp(app *backpack.App) *slog.Logger {
	if app != nil {
		if log, ok := app.Lookup[*slog.Logger](); ok && log != nil {
			return log
		}
	}
	return slog.Default()
}