package job

import (
	"context"
	"fmt"
	"strings"

	"haixun-backend/internal/library/publishschedule"
	copydraftdomain "haixun-backend/internal/model/copy_draft/domain/usecase"
	missiondomain "haixun-backend/internal/model/copy_mission/domain/usecase"
	jobdom "haixun-backend/internal/model/job/domain/usecase"
	inventorydomain "haixun-backend/internal/model/publish_inventory/domain/usecase"
	pqdomain "haixun-backend/internal/model/publish_queue/domain/usecase"
)

type RefillPublishInventoryDeps struct {
	Jobs             jobdom.UseCase
	PublishInventory inventorydomain.UseCase
	PublishQueue     pqdomain.UseCase
	CopyMission      missiondomain.UseCase
	CopyDraft        copydraftdomain.UseCase
}

func RegisterRefillPublishInventoryHandler(runner *Runner, deps RefillPublishInventoryDeps) {
	if runner == nil {
		return
	}
	runner.RegisterStepHandler("refill_publish_inventory", func(ctx context.Context, step StepContext) error {
		return runRefillPublishInventory(ctx, step, deps)
	})
}

func runRefillPublishInventory(ctx context.Context, step StepContext, deps RefillPublishInventoryDeps) error {
	payload := step.Run.Payload
	tenantID, ownerUID := runActorFromPayload(payload, step.Run)
	accountID := stringField(payload, "account_id")
	if tenantID == "" || ownerUID == "" || accountID == "" {
		return fmt.Errorf("refill publish inventory payload missing tenant_id, owner_uid, or account_id")
	}
	if deps.PublishInventory == nil || deps.PublishQueue == nil {
		return fmt.Errorf("publish inventory dependencies are not configured")
	}
	policy, err := deps.PublishInventory.Get(ctx, tenantID, ownerUID, accountID)
	if err != nil {
		return err
	}
	if !policy.Enabled {
		return nil
	}
	health, err := deps.PublishQueue.ListPublishHealth(ctx, tenantID, ownerUID, accountID, 1, 1)
	if err != nil {
		return err
	}
	need := policy.LowStockThreshold - int(health.Summary.PendingScheduled)
	if requested := intField(payload, "count"); requested > 0 {
		need = requested
	}
	if need <= 0 {
		return nil
	}
	if need > 12 {
		need = 12
	}
	slots := make([]publishschedule.Slot, 0, len(policy.Slots))
	for _, slot := range policy.Slots {
		slots = append(slots, publishschedule.Slot{Weekday: slot.Weekday, Time: slot.Time})
	}
	times := publishschedule.BuildSchedule(0, policy.Timezone, slots, need)
	for i := 0; i < need; i++ {
		if err := step.Heartbeat(ctx); err != nil {
			return err
		}
		ref := pickSourceRef(policy.SourceRefs, i)
		text, personaID, missionID := refillText(ctx, deps, tenantID, ownerUID, ref, i)
		createReq := pqdomain.CreateRequest{
			TenantID: tenantID, OwnerUID: ownerUID, AccountID: accountID,
			PersonaID: personaID, CopyMissionID: missionID, Text: text,
		}
		if i < len(times) {
			createReq.ScheduledAt = times[i]
		}
		if deps.CopyDraft != nil && personaID != "" {
			draft, err := deps.CopyDraft.Create(ctx, copydraftdomain.CreateRequest{
				TenantID: tenantID, OwnerUID: ownerUID, PersonaID: personaID,
				CopyMissionID: missionID, DraftType: "inventory-refill", SortOrder: i + 1,
				Text: text, Rationale: "自動補庫存產生",
			})
			if err == nil && draft != nil {
				createReq.CopyDraftID = draft.ID
			}
		}
		item, err := deps.PublishQueue.Create(ctx, createReq)
		if err != nil {
			return err
		}
		if deps.CopyDraft != nil && createReq.CopyDraftID != "" {
			_, _ = deps.CopyDraft.MarkScheduled(ctx, copydraftdomain.MarkScheduledRequest{
				TenantID: tenantID, OwnerUID: ownerUID, PersonaID: personaID, DraftID: createReq.CopyDraftID, QueueID: item.ID,
			})
		}
	}
	return nil
}

func pickSourceRef(items []inventorydomain.SourceRef, idx int) inventorydomain.SourceRef {
	if len(items) == 0 {
		return inventorydomain.SourceRef{Type: "manual_seed", ManualSeed: "分享一個今天巡樓觀察到的重點"}
	}
	return items[idx%len(items)]
}

func refillText(ctx context.Context, deps RefillPublishInventoryDeps, tenantID, ownerUID string, ref inventorydomain.SourceRef, idx int) (string, string, string) {
	personaID := strings.TrimSpace(ref.PersonaID)
	missionID := strings.TrimSpace(ref.CopyMissionID)
	seed := strings.TrimSpace(ref.ManualSeed)
	if missionID != "" && personaID != "" && deps.CopyMission != nil {
		if mission, err := deps.CopyMission.Get(ctx, tenantID, ownerUID, personaID, missionID); err == nil {
			seed = strings.TrimSpace(firstNonEmpty(mission.Brief, mission.Label, mission.SeedQuery))
		}
	}
	if seed == "" {
		seed = "分享一個今天巡樓觀察到的重點"
	}
	return fmt.Sprintf("%s\n\n巡樓筆記 #%d", seed, idx+1), personaID, missionID
}

func firstNonEmpty(values ...string) string {
	for _, value := range values {
		if strings.TrimSpace(value) != "" {
			return strings.TrimSpace(value)
		}
	}
	return ""
}