package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"math"
	"os"
	"sort"
	"strings"
	"time"

	commonSvc "gitlab.com/mbugroup/lti-api.git/internal/common/service"
	"gitlab.com/mbugroup/lti-api.git/internal/config"
	"gitlab.com/mbugroup/lti-api.git/internal/database"
	entity "gitlab.com/mbugroup/lti-api.git/internal/entities"
	"gitlab.com/mbugroup/lti-api.git/internal/utils/fifo"
	"gorm.io/gorm"
)

type productWarehouseScopeRow struct {
	ProductWarehouseID    uint  `gorm:"column:product_warehouse_id"`
	ProductID             uint  `gorm:"column:product_id"`
	WarehouseID           uint  `gorm:"column:warehouse_id"`
	ProjectFlockKandangID *uint `gorm:"column:project_flock_kandang_id"`
}

type reflowTarget struct {
	ProductWarehouseID    uint
	ProductID             uint
	WarehouseID           uint
	ProjectFlockKandangID *uint
	FlagGroupCode         string
}

func main() {
	var (
		projectFlockKandangID uint
		apply                 bool
		asOfRaw               string
		includeShared         bool
	)

	flag.UintVar(&projectFlockKandangID, "project-flock-kandang-id", 0, "Project flock kandang ID (required)")
	flag.BoolVar(&apply, "apply", false, "Apply reflow. If false, run as dry-run")
	flag.StringVar(&asOfRaw, "as-of", "", "Optional AsOf boundary. Format: RFC3339 or YYYY-MM-DD")
	flag.BoolVar(&includeShared, "include-shared", true, "Include product warehouses referenced by transactions in this PFK scope (including shared/non-bound product warehouses)")
	flag.Parse()

	if projectFlockKandangID == 0 {
		log.Fatal("--project-flock-kandang-id is required")
	}

	asOf, err := parseAsOf(asOfRaw)
	if err != nil {
		log.Fatalf("invalid --as-of: %v", err)
	}

	ctx := context.Background()
	db := database.Connect(config.DBHost, config.DBName)
	fifoStockV2Svc := commonSvc.NewFifoStockV2Service(db, nil)

	exists, err := projectFlockKandangExists(ctx, db, projectFlockKandangID)
	if err != nil {
		log.Fatalf("failed to check project flock kandang: %v", err)
	}
	if !exists {
		log.Fatalf("project_flock_kandang_id %d not found", projectFlockKandangID)
	}

	scopedPWs, err := loadScopedProductWarehouses(ctx, db, projectFlockKandangID, includeShared)
	if err != nil {
		log.Fatalf("failed to load scoped product warehouses: %v", err)
	}
	if len(scopedPWs) == 0 {
		fmt.Printf("Mode: %s\n", modeLabel(apply))
		fmt.Printf("Scope: project_flock_kandang_id=%d\n", projectFlockKandangID)
		fmt.Println("No product warehouse found in scope")
		return
	}

	targets := make([]reflowTarget, 0, len(scopedPWs))
	skippedPW := 0
	failedResolve := 0

	for _, pw := range scopedPWs {
		flagGroups, err := resolveFlagGroupsByProductWarehouse(ctx, db, pw.ProductWarehouseID)
		if err != nil {
			fmt.Printf("FAIL pw=%d error=resolve flag groups: %v\n", pw.ProductWarehouseID, err)
			failedResolve++
			continue
		}
		if len(flagGroups) == 0 {
			fmt.Printf("SKIP pw=%d reason=no active fifo v2 route by product flag\n", pw.ProductWarehouseID)
			skippedPW++
			continue
		}
		for _, group := range flagGroups {
			targets = append(targets, reflowTarget{
				ProductWarehouseID:    pw.ProductWarehouseID,
				ProductID:             pw.ProductID,
				WarehouseID:           pw.WarehouseID,
				ProjectFlockKandangID: pw.ProjectFlockKandangID,
				FlagGroupCode:         group,
			})
		}
	}

	sort.Slice(targets, func(i, j int) bool {
		if targets[i].ProductWarehouseID == targets[j].ProductWarehouseID {
			return targets[i].FlagGroupCode < targets[j].FlagGroupCode
		}
		return targets[i].ProductWarehouseID < targets[j].ProductWarehouseID
	})

	fmt.Printf("Mode: %s\n", modeLabel(apply))
	fmt.Printf("Scope: project_flock_kandang_id=%d include_shared=%t\n", projectFlockKandangID, includeShared)
	if asOf != nil {
		fmt.Printf("AsOf: %s\n", asOf.UTC().Format(time.RFC3339))
	} else {
		fmt.Println("AsOf: <nil> (full timeline)")
	}
	fmt.Printf("Product warehouses in scope: %d\n", len(scopedPWs))
	fmt.Printf("Planned reflow targets: %d\n\n", len(targets))

	for _, target := range targets {
		fmt.Printf(
			"PLAN pw=%d product=%d warehouse=%d pw_pfk=%s flag_group=%s\n",
			target.ProductWarehouseID,
			target.ProductID,
			target.WarehouseID,
			displayOptionalUint(target.ProjectFlockKandangID),
			target.FlagGroupCode,
		)
	}

	if !apply {
		fmt.Println()
		fmt.Printf("Summary: planned=%d skipped_pw=%d failed_resolve=%d applied=0 failed_apply=0\n", len(targets), skippedPW, failedResolve)
		if failedResolve > 0 {
			os.Exit(1)
		}
		return
	}

	successApply := 0
	failedApply := 0
	for idx, target := range targets {
		req := commonSvc.FifoStockV2ReflowRequest{
			FlagGroupCode:      target.FlagGroupCode,
			ProductWarehouseID: target.ProductWarehouseID,
			AsOf:               asOf,
			IdempotencyKey: fmt.Sprintf(
				"manual-pfk-reflow-%d-%d-%s-%d-%d",
				projectFlockKandangID,
				target.ProductWarehouseID,
				strings.ToUpper(strings.TrimSpace(target.FlagGroupCode)),
				time.Now().UnixNano(),
				idx,
			),
		}

		res, err := fifoStockV2Svc.Reflow(ctx, req)
		if err != nil {
			fmt.Printf("FAIL pw=%d flag_group=%s error=%v\n", target.ProductWarehouseID, target.FlagGroupCode, err)
			failedApply++
			continue
		}

		fmt.Printf(
			"DONE pw=%d flag_group=%s rollback=%.3f allocate=%.3f pending=%.3f processed_usable=%d\n",
			target.ProductWarehouseID,
			target.FlagGroupCode,
			res.Rollback.ReleasedQty,
			res.Allocate.AllocatedQty,
			res.Allocate.PendingQty,
			res.ProcessedUsables,
		)
		successApply++
	}

	orphanPopulationRows := int64(0)
	syncedPopulationQtyRows := int64(0)
	syncedPopulationUsedRows := int64(0)
	traceReleasedRows := int64(0)
	traceInsertedRows := int64(0)
	if rowsOrphan, rowsQty, rowsUsed, err := resyncProjectFlockPopulation(ctx, db, projectFlockKandangID); err != nil {
		fmt.Printf("FAIL population_resync project_flock_kandang_id=%d error=%v\n", projectFlockKandangID, err)
		failedApply++
	} else {
		orphanPopulationRows = rowsOrphan
		syncedPopulationQtyRows = rowsQty
		syncedPopulationUsedRows = rowsUsed
		fmt.Printf(
			"SYNC project_flock_populations orphan_marked=%d qty_synced=%d used_synced=%d\n",
			orphanPopulationRows,
			syncedPopulationQtyRows,
			syncedPopulationUsedRows,
		)
	}

	if released, inserted, err := resyncChickinTraceByProjectFlockKandang(ctx, db, fifoStockV2Svc, projectFlockKandangID); err != nil {
		fmt.Printf("FAIL chickin_trace_resync project_flock_kandang_id=%d error=%v\n", projectFlockKandangID, err)
		failedApply++
	} else {
		traceReleasedRows = released
		traceInsertedRows = inserted
		fmt.Printf(
			"SYNC chickin_trace released=%d inserted=%d\n",
			traceReleasedRows,
			traceInsertedRows,
		)
	}

	fmt.Println()
	fmt.Printf(
		"Summary: planned=%d skipped_pw=%d failed_resolve=%d applied=%d failed_apply=%d population_orphan=%d population_qty_synced=%d population_used_synced=%d trace_released=%d trace_inserted=%d\n",
		len(targets),
		skippedPW,
		failedResolve,
		successApply,
		failedApply,
		orphanPopulationRows,
		syncedPopulationQtyRows,
		syncedPopulationUsedRows,
		traceReleasedRows,
		traceInsertedRows,
	)
	if failedResolve > 0 || failedApply > 0 {
		os.Exit(1)
	}
}

func parseAsOf(raw string) (*time.Time, error) {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return nil, nil
	}

	layouts := []string{
		time.RFC3339Nano,
		time.RFC3339,
		"2006-01-02 15:04:05",
		"2006-01-02",
	}

	for _, layout := range layouts {
		parsed, err := time.Parse(layout, raw)
		if err != nil {
			continue
		}
		if layout == "2006-01-02" {
			endOfDay := time.Date(parsed.Year(), parsed.Month(), parsed.Day(), 23, 59, 59, int(time.Second-time.Nanosecond), time.UTC)
			return &endOfDay, nil
		}
		asOf := parsed.UTC()
		return &asOf, nil
	}

	return nil, fmt.Errorf("unsupported format %q", raw)
}

func modeLabel(apply bool) string {
	if apply {
		return "APPLY"
	}
	return "DRY-RUN"
}

func displayOptionalUint(v *uint) string {
	if v == nil {
		return "NULL"
	}
	return fmt.Sprintf("%d", *v)
}

func projectFlockKandangExists(ctx context.Context, db *gorm.DB, projectFlockKandangID uint) (bool, error) {
	var count int64
	err := db.WithContext(ctx).
		Table("project_flock_kandangs").
		Where("id = ?", projectFlockKandangID).
		Count(&count).Error
	if err != nil {
		return false, err
	}
	return count > 0, nil
}

func loadScopedProductWarehouses(ctx context.Context, db *gorm.DB, projectFlockKandangID uint, includeShared bool) ([]productWarehouseScopeRow, error) {
	if !includeShared {
		var rows []productWarehouseScopeRow
		err := db.WithContext(ctx).
			Table("product_warehouses").
			Select("id AS product_warehouse_id, product_id, warehouse_id, project_flock_kandang_id").
			Where("project_flock_kandang_id = ?", projectFlockKandangID).
			Order("id ASC").
			Scan(&rows).Error
		if err != nil {
			return nil, err
		}
		return rows, nil
	}

	query := `
		WITH scoped_pw AS (
			SELECT pw.id AS product_warehouse_id
			FROM product_warehouses pw
			WHERE pw.project_flock_kandang_id = ?

			UNION
			SELECT pc.product_warehouse_id
			FROM project_chickins pc
			WHERE pc.project_flock_kandang_id = ?
				AND pc.deleted_at IS NULL

			UNION
			SELECT rs.product_warehouse_id
			FROM recordings r
			JOIN recording_stocks rs ON rs.recording_id = r.id
			WHERE r.project_flock_kandangs_id = ?
				AND r.deleted_at IS NULL

			UNION
			SELECT rd.product_warehouse_id
			FROM recordings r
			JOIN recording_depletions rd ON rd.recording_id = r.id
			WHERE r.project_flock_kandangs_id = ?
				AND r.deleted_at IS NULL

			UNION
			SELECT rd.source_product_warehouse_id
			FROM recordings r
			JOIN recording_depletions rd ON rd.recording_id = r.id
			WHERE r.project_flock_kandangs_id = ?
				AND r.deleted_at IS NULL
				AND rd.source_product_warehouse_id IS NOT NULL

			UNION
			SELECT re.product_warehouse_id
			FROM recordings r
			JOIN recording_eggs re ON re.recording_id = r.id
			WHERE r.project_flock_kandangs_id = ?
				AND r.deleted_at IS NULL

			UNION
			SELECT lts.product_warehouse_id
			FROM laying_transfer_sources lts
			WHERE lts.source_project_flock_kandang_id = ?
				AND lts.deleted_at IS NULL
				AND lts.product_warehouse_id IS NOT NULL

			UNION
			SELECT ltt.product_warehouse_id
			FROM laying_transfer_targets ltt
			WHERE ltt.target_project_flock_kandang_id = ?
				AND ltt.deleted_at IS NULL
				AND ltt.product_warehouse_id IS NOT NULL

			UNION
			SELECT pi.product_warehouse_id
			FROM purchase_items pi
			WHERE pi.project_flock_kandang_id = ?
				AND pi.product_warehouse_id IS NOT NULL
		)
		SELECT DISTINCT
			pw.id AS product_warehouse_id,
			pw.product_id,
			pw.warehouse_id,
			pw.project_flock_kandang_id
		FROM scoped_pw s
		JOIN product_warehouses pw ON pw.id = s.product_warehouse_id
		ORDER BY pw.id ASC
	`

	var rows []productWarehouseScopeRow
	err := db.WithContext(ctx).
		Raw(
			query,
			projectFlockKandangID,
			projectFlockKandangID,
			projectFlockKandangID,
			projectFlockKandangID,
			projectFlockKandangID,
			projectFlockKandangID,
			projectFlockKandangID,
			projectFlockKandangID,
			projectFlockKandangID,
		).
		Scan(&rows).Error
	if err != nil {
		return nil, err
	}
	return rows, nil
}

func resolveFlagGroupsByProductWarehouse(ctx context.Context, db *gorm.DB, productWarehouseID uint) ([]string, error) {
	var groups []string
	err := db.WithContext(ctx).
		Table("fifo_stock_v2_route_rules rr").
		Select("DISTINCT rr.flag_group_code").
		Joins("JOIN fifo_stock_v2_flag_groups fg ON fg.code = rr.flag_group_code AND fg.is_active = TRUE").
		Where("rr.is_active = TRUE").
		Where(`
			EXISTS (
				SELECT 1
				FROM product_warehouses pw
				JOIN flags f ON f.flagable_id = pw.product_id
				JOIN fifo_stock_v2_flag_members fm ON fm.flag_name = f.name AND fm.is_active = TRUE
				WHERE pw.id = ?
					AND f.flagable_type = ?
					AND fm.flag_group_code = rr.flag_group_code
			)
		`, productWarehouseID, entity.FlagableTypeProduct).
		Order("rr.flag_group_code ASC").
		Scan(&groups).Error
	if err != nil {
		return nil, err
	}
	return groups, nil
}

func resyncProjectFlockPopulation(ctx context.Context, db *gorm.DB, projectFlockKandangID uint) (int64, int64, int64, error) {
	if projectFlockKandangID == 0 {
		return 0, 0, 0, nil
	}

	orphanResult := db.WithContext(ctx).Exec(`
		UPDATE project_flock_populations pfp
		SET deleted_at = NOW(),
			updated_at = NOW()
		FROM project_chickins pc
		WHERE pfp.project_chickin_id = pc.id
		  AND pc.project_flock_kandang_id = ?
		  AND pc.deleted_at IS NOT NULL
		  AND pfp.deleted_at IS NULL
	`, projectFlockKandangID)
	if orphanResult.Error != nil {
		return 0, 0, 0, orphanResult.Error
	}

	qtyResult := db.WithContext(ctx).Exec(`
		UPDATE project_flock_populations p
		SET total_qty = GREATEST(COALESCE(pc.usage_qty, 0), 0),
			updated_at = NOW()
		FROM project_chickins pc
		WHERE p.project_chickin_id = pc.id
		  AND pc.project_flock_kandang_id = ?
		  AND pc.deleted_at IS NULL
		  AND p.deleted_at IS NULL
	`, projectFlockKandangID)
	if qtyResult.Error != nil {
		return 0, 0, 0, qtyResult.Error
	}

	usedResult := db.WithContext(ctx).Exec(`
		WITH scoped AS (
			SELECT pfp.id, pfp.total_qty
			FROM project_flock_populations pfp
			JOIN project_chickins pc ON pc.id = pfp.project_chickin_id
			WHERE pc.project_flock_kandang_id = ?
			  AND pc.deleted_at IS NULL
			  AND pfp.deleted_at IS NULL
		),
		alloc AS (
			SELECT sa.stockable_id, SUM(sa.qty) AS used_qty
			FROM stock_allocations sa
			WHERE sa.stockable_type = 'PROJECT_FLOCK_POPULATION'
			  AND sa.status = 'ACTIVE'
				  AND sa.allocation_purpose = 'CONSUME'
				GROUP BY sa.stockable_id
			)
		UPDATE project_flock_populations p
		SET total_used_qty = LEAST(COALESCE(a.used_qty, 0), GREATEST(s.total_qty, 0)),
			updated_at = NOW()
		FROM scoped s
		LEFT JOIN alloc a ON a.stockable_id = s.id
		WHERE p.id = s.id
	`, projectFlockKandangID)
	if usedResult.Error != nil {
		return 0, 0, 0, usedResult.Error
	}

	return orphanResult.RowsAffected, qtyResult.RowsAffected, usedResult.RowsAffected, nil
}
func resyncChickinTraceByProjectFlockKandang(
	ctx context.Context,
	db *gorm.DB,
	fifoStockV2Svc commonSvc.FifoStockV2Service,
	projectFlockKandangID uint,
) (int64, int64, error) {
	if projectFlockKandangID == 0 {
		return 0, 0, nil
	}

	var productWarehouseIDs []uint
	if err := db.WithContext(ctx).
		Table("project_chickins").
		Distinct("product_warehouse_id").
		Where("project_flock_kandang_id = ?", projectFlockKandangID).
		Where("deleted_at IS NULL").
		Order("product_warehouse_id ASC").
		Pluck("product_warehouse_id", &productWarehouseIDs).Error; err != nil {
		return 0, 0, err
	}
	if len(productWarehouseIDs) == 0 {
		return 0, 0, nil
	}

	totalReleased := int64(0)
	totalInserted := int64(0)

	for _, productWarehouseID := range productWarehouseIDs {
		var releasedRows int64
		var insertedRows int64

		err := db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
			flagGroups, err := resolveFlagGroupsByProductWarehouse(ctx, tx, productWarehouseID)
			if err != nil {
				return err
			}
			if len(flagGroups) == 0 {
				return nil
			}
			flagGroupCode := strings.TrimSpace(flagGroups[0])
			if flagGroupCode == "" {
				return nil
			}

			released := tx.WithContext(ctx).
				Table("stock_allocations").
				Where("product_warehouse_id = ?", productWarehouseID).
				Where("usable_type = ?", fifo.UsableKeyProjectChickin.String()).
				Where("allocation_purpose = ?", entity.StockAllocationPurposeTraceChickin).
				Where("status = ?", entity.StockAllocationStatusActive).
				Updates(map[string]any{
					"status":      entity.StockAllocationStatusReleased,
					"released_at": time.Now(),
					"updated_at":  time.Now(),
					"note":        "chickin_trace_reflow_reset",
				})
			if released.Error != nil {
				return released.Error
			}
			releasedRows = released.RowsAffected

			type chickinRow struct {
				ID       uint      `gorm:"column:id"`
				UsageQty float64   `gorm:"column:usage_qty"`
				ChickIn  time.Time `gorm:"column:chick_in_date"`
			}
			chickins := make([]chickinRow, 0)
			if err := tx.WithContext(ctx).
				Table("project_chickins").
				Select("id, usage_qty, chick_in_date").
				Where("product_warehouse_id = ?", productWarehouseID).
				Where("deleted_at IS NULL").
				Where("usage_qty > 0").
				Order("chick_in_date ASC, id ASC").
				Scan(&chickins).Error; err != nil {
				return err
			}
			if len(chickins) == 0 {
				return nil
			}

			gatherRows, err := fifoStockV2Svc.Gather(ctx, commonSvc.FifoStockV2GatherRequest{
				FlagGroupCode:      flagGroupCode,
				Lane:               "STOCKABLE",
				AllocationPurpose:  entity.StockAllocationPurposeTraceChickin,
				IgnoreSourceUsed:   true,
				ProductWarehouseID: productWarehouseID,
				Limit:              50000,
				Tx:                 tx,
			})
			if err != nil {
				return err
			}
			if len(gatherRows) == 0 {
				return nil
			}

			type lotKey struct {
				StockableType string
				StockableID   uint
			}
			remainingByLot := make(map[lotKey]float64, len(gatherRows))
			for _, row := range gatherRows {
				key := lotKey{StockableType: row.Ref.LegacyTypeKey, StockableID: row.Ref.ID}
				remainingByLot[key] = row.AvailableQuantity
			}

			now := time.Now()
			lotIndex := 0
			for _, chickinRow := range chickins {
				remaining := chickinRow.UsageQty
				for remaining > 1e-6 && lotIndex < len(gatherRows) {
					lot := gatherRows[lotIndex]
					key := lotKey{StockableType: lot.Ref.LegacyTypeKey, StockableID: lot.Ref.ID}
					available := remainingByLot[key]
					if available <= 1e-6 {
						lotIndex++
						continue
					}

					portion := math.Min(remaining, available)
					if portion <= 1e-6 {
						lotIndex++
						continue
					}

					insert := map[string]any{
						"product_warehouse_id": productWarehouseID,
						"stockable_type":       lot.Ref.LegacyTypeKey,
						"stockable_id":         lot.Ref.ID,
						"usable_type":          fifo.UsableKeyProjectChickin.String(),
						"usable_id":            chickinRow.ID,
						"qty":                  portion,
						"status":               entity.StockAllocationStatusActive,
						"allocation_purpose":   entity.StockAllocationPurposeTraceChickin,
						"engine_version":       "v2",
						"flag_group_code":      flagGroupCode,
						"function_code":        "CHICKIN_TRACE",
						"created_at":           now,
						"updated_at":           now,
					}
					if err := tx.WithContext(ctx).Table("stock_allocations").Create(insert).Error; err != nil {
						return err
					}

					insertedRows++
					remaining -= portion
					remainingByLot[key] = available - portion
				}
			}

			return nil
		})
		if err != nil {
			return totalReleased, totalInserted, err
		}

		totalReleased += releasedRows
		totalInserted += insertedRows
	}

	return totalReleased, totalInserted, nil
}