// Command normalize-recording-cutover-depletion
//
// Data-only normalization of recording population metrics for a cut-over flock
// where pre-cutover mortality (culling + dead) was booked via stock adjustments
// (which do NOT feed the recording population). It applies an "opening depletion"
// offset to the CUMULATIVE depletion of every recording in a project_flock_kandang,
// recomputing the population-dependent metric columns DIRECTLY on the `recordings`
// table.
//
// It does NOT touch recording_depletions, stock_allocations, product_warehouses,
// project_flock_populations, or adjustment_stocks — so inventory/FIFO stay intact
// (the existing adjustments keep owning the stock movement).
//
// Recomputed columns (per recording, ordered by record_datetime,id):
//
//	cumDepByDate = running SUM(recording_depletions.qty) up to that recording (INVARIANT)
//	new_tcq            = initialChickin - cumDepByDate - opening
//	cum_depletion_rate = (cumDepByDate + opening) / initialChickin * 100
//	feed_intake        = feed_intake_old * (old_total_chick_qty / new_tcq)   [null->null]
//	fcr_value          = fcr_value_old   * (old_total_chick_qty / new_tcq)   [null->null]
//
// cum_intake and egg-based metrics are left untouched (see plan).
//
// Idempotent: only rows where total_chick_qty IS DISTINCT FROM new_tcq are updated.
// Self-check: run with -opening=0; consistent rows are no-ops, any row that changes
// was already inconsistent (stale) and gets reconciled to follow the depletion data.
//
// Usage:
//
//	DB_HOST=localhost DB_PORT=5542 go run ./cmd/normalize-recording-cutover-depletion/ -pfk=91 -opening=0          # self-check dry-run
//	DB_HOST=localhost DB_PORT=5542 go run ./cmd/normalize-recording-cutover-depletion/ -pfk=91 -opening=3126       # dry-run
//	DB_HOST=localhost DB_PORT=5542 go run ./cmd/normalize-recording-cutover-depletion/ -pfk=91 -opening=3126 -apply # apply
package main

import (
	"flag"
	"fmt"
	"log"
	"math"
	"os"
	"text/tabwriter"

	"gitlab.com/mbugroup/lti-api.git/internal/config"
	"gitlab.com/mbugroup/lti-api.git/internal/database"
	"gorm.io/gorm"
)

type recRow struct {
	ID               uint     `gorm:"column:id"`
	Day              *int     `gorm:"column:day"`
	RecordDate       string   `gorm:"column:record_date"`
	TotalChickQty    *float64 `gorm:"column:total_chick_qty"`
	CumDepletionRate *float64 `gorm:"column:cum_depletion_rate"`
	FeedIntake       *float64 `gorm:"column:feed_intake"`
	FcrValue         *float64 `gorm:"column:fcr_value"`
	CumDepByDate     float64  `gorm:"column:cum_dep_by_date"`
}

const eps = 1e-6

func main() {
	var (
		pfk             uint
		opening         float64
		apply           bool
		chickinOverride float64
	)
	flag.UintVar(&pfk, "pfk", 0, "project_flock_kandangs_id (required)")
	flag.Float64Var(&opening, "opening", 0, "opening depletion qty added to cumulative depletion of every recording")
	flag.BoolVar(&apply, "apply", false, "apply changes (default: dry-run)")
	flag.Float64Var(&chickinOverride, "chickin", 0, "override initial chickin base (0 = auto SUM project_chickins.usage_qty)")
	flag.Parse()

	if pfk == 0 {
		log.Fatal("-pfk is required")
	}

	db := database.Connect(config.DBHost, config.DBName)

	// 1) initial chickin base
	var initialChickin float64
	if chickinOverride > 0 {
		initialChickin = chickinOverride
	} else {
		if err := db.Raw(
			`SELECT COALESCE(SUM(usage_qty),0) FROM project_chickins WHERE project_flock_kandang_id = ?`, pfk,
		).Scan(&initialChickin).Error; err != nil {
			log.Fatalf("query initial chickin: %v", err)
		}
	}
	if initialChickin <= 0 {
		log.Fatalf("initial chickin <= 0 for pfk %d (got %.3f)", pfk, initialChickin)
	}

	// 2) sanity: duplicate record_datetime would make cumulative-by-date ambiguous
	var dupDatetimes int64
	if err := db.Raw(
		`SELECT COUNT(*) FROM (
		   SELECT record_datetime FROM recordings
		   WHERE project_flock_kandangs_id = ? AND deleted_at IS NULL
		   GROUP BY record_datetime HAVING COUNT(*) > 1
		 ) t`, pfk,
	).Scan(&dupDatetimes).Error; err != nil {
		log.Fatalf("check duplicate datetimes: %v", err)
	}
	if dupDatetimes > 0 {
		fmt.Printf("WARNING: %d duplicate record_datetime group(s) for pfk %d — cumulative-by-date ordering may be ambiguous; review carefully.\n\n", dupDatetimes, pfk)
	}

	// 3) load recordings + running cumulative depletion (by record_datetime, id)
	var rows []recRow
	q := `
	WITH dep AS (
	  SELECT r.id, r.day, r.record_datetime,
	         r.total_chick_qty, r.cum_depletion_rate, r.feed_intake, r.fcr_value,
	         COALESCE((SELECT SUM(rd.qty) FROM recording_depletions rd WHERE rd.recording_id = r.id), 0) AS daily_dep
	  FROM recordings r
	  WHERE r.project_flock_kandangs_id = ? AND r.deleted_at IS NULL
	)
	SELECT id, day,
	       to_char(record_datetime, 'YYYY-MM-DD') AS record_date,
	       total_chick_qty, cum_depletion_rate, feed_intake, fcr_value,
	       SUM(daily_dep) OVER (ORDER BY record_datetime, id) AS cum_dep_by_date
	FROM dep
	ORDER BY record_datetime, id`
	if err := db.Raw(q, pfk).Scan(&rows).Error; err != nil {
		log.Fatalf("query recordings: %v", err)
	}
	if len(rows) == 0 {
		log.Fatalf("no recordings found for pfk %d", pfk)
	}

	mode := "DRY-RUN"
	if apply {
		mode = "APPLY"
	}
	fmt.Printf("=== normalize-recording-cutover-depletion ===\n")
	fmt.Printf("Mode: %s | pfk=%d | initialChickin=%.3f | opening=%.3f | recordings=%d\n\n", mode, pfk, initialChickin, opening, len(rows))

	tw := tabwriter.NewWriter(os.Stdout, 0, 2, 2, ' ', 0)
	fmt.Fprintln(tw, "id\tday\tdate\ttcq_old->new\tcumRate_old->new\tfeed_old->new\tfcr_old->new\tstatus")

	var willChange, anomalies, skipped int
	var negTcq int
	for _, r := range rows {
		newTcq := initialChickin - r.CumDepByDate - opening
		newRate := (r.CumDepByDate + opening) / initialChickin * 100

		status := ""
		// detect pre-existing inconsistency (stale row): old tcq != invariant base (opening=0 expectation)
		expectedBase := initialChickin - r.CumDepByDate
		if r.TotalChickQty == nil || math.Abs(*r.TotalChickQty-expectedBase) > 1e-3 {
			status = "ANOMALY"
			anomalies++
		}

		if newTcq < -eps {
			status = "NEG_TCQ!"
			negTcq++
		}

		// idempotent guard
		if r.TotalChickQty != nil && math.Abs(*r.TotalChickQty-newTcq) < 1e-6 {
			if status == "" {
				status = "noop"
			}
			skipped++
		} else {
			willChange++
		}

		var newFeed, newFcr *float64
		if r.FeedIntake != nil && r.TotalChickQty != nil && math.Abs(newTcq) > eps {
			v := *r.FeedIntake * (*r.TotalChickQty / newTcq)
			newFeed = &v
		} else {
			newFeed = r.FeedIntake
		}
		if r.FcrValue != nil && r.TotalChickQty != nil && math.Abs(newTcq) > eps {
			v := *r.FcrValue * (*r.TotalChickQty / newTcq)
			newFcr = &v
		} else {
			newFcr = r.FcrValue
		}

		fmt.Fprintf(tw, "%d\t%s\t%s\t%s -> %.3f\t%s -> %.3f\t%s -> %s\t%s -> %s\t%s\n",
			r.ID, iptr(r.Day), r.RecordDate,
			fptr(r.TotalChickQty), newTcq,
			fptr(r.CumDepletionRate), newRate,
			fptr(r.FeedIntake), fptrV(newFeed),
			fptr(r.FcrValue), fptrV(newFcr),
			status,
		)
	}
	tw.Flush()

	fmt.Printf("\nSummary: will_change=%d skipped(noop)=%d anomalies=%d neg_tcq=%d\n", willChange, skipped, anomalies, negTcq)
	if negTcq > 0 {
		log.Fatalf("ABORT: %d recording(s) would get negative total_chick_qty — opening too large or data issue", negTcq)
	}

	if !apply {
		fmt.Println("\nDry-run only. Re-run with -apply to persist.")
		return
	}

	// 4) APPLY — single set-based UPDATE in a transaction (RHS uses pre-update column values)
	err := db.Transaction(func(tx *gorm.DB) error {
		res := tx.Exec(`
		WITH dep AS (
		  SELECT r.id, r.record_datetime,
		         COALESCE((SELECT SUM(rd.qty) FROM recording_depletions rd WHERE rd.recording_id = r.id), 0) AS daily_dep
		  FROM recordings r
		  WHERE r.project_flock_kandangs_id = ? AND r.deleted_at IS NULL
		),
		calc AS (
		  SELECT id,
		         (? - cum_dep - ?) AS new_tcq,
		         ((cum_dep + ?) / ? * 100) AS new_rate
		  FROM (
		    SELECT id, SUM(daily_dep) OVER (ORDER BY record_datetime, id) AS cum_dep
		    FROM dep
		  ) s
		)
		UPDATE recordings r SET
		  total_chick_qty   = c.new_tcq,
		  cum_depletion_rate = c.new_rate,
		  feed_intake = CASE WHEN r.feed_intake IS NULL OR r.total_chick_qty IS NULL OR c.new_tcq = 0
		                     THEN r.feed_intake ELSE r.feed_intake * (r.total_chick_qty / c.new_tcq) END,
		  fcr_value   = CASE WHEN r.fcr_value IS NULL OR r.total_chick_qty IS NULL OR c.new_tcq = 0
		                     THEN r.fcr_value ELSE r.fcr_value * (r.total_chick_qty / c.new_tcq) END,
		  updated_at = NOW()
		FROM calc c
		WHERE r.id = c.id
		  AND r.total_chick_qty IS DISTINCT FROM c.new_tcq`,
			pfk,
			initialChickin, opening,
			opening, initialChickin,
		)
		if res.Error != nil {
			return res.Error
		}
		fmt.Printf("\nAPPLIED: %d recording row(s) updated.\n", res.RowsAffected)
		return nil
	})
	if err != nil {
		log.Fatalf("apply failed: %v", err)
	}
	fmt.Println("Done. Verify with the queries in tmp/pfk91-cutover-fix.md.")
}

func fptr(p *float64) string {
	if p == nil {
		return "null"
	}
	return fmt.Sprintf("%.3f", *p)
}

func fptrV(p *float64) string { return fptr(p) }

func iptr(p *int) string {
	if p == nil {
		return "-"
	}
	return fmt.Sprintf("%d", *p)
}