package catalog

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"

	"github.com/descrybe/descrybe-v2/apps/api/internal/company"
	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"
)

const enhanceInputHashKey = "enhance_input_hash"

// RepairWeakEnhanceHashesResult is the detailed report for weak-hash clearing.
type RepairWeakEnhanceHashesResult struct {
	Cleared         int64
	Scanned         int
	ClearedRawIDs   []uuid.UUID
}

// RepairWeakEnhanceHashes clears enhance_input_hash from field_sources and
// localized_content for processed products whose descriptions are weak /
// title-echo / filler / invent-synthesize (so the next enhance cannot hash-skip
// thin or heuristic priors).
// Returns the number of products updated.
func RepairWeakEnhanceHashes(ctx context.Context, pool *pgxpool.Pool, companyID uuid.UUID) (int64, error) {
	res, err := RepairWeakEnhanceHashesDetailed(ctx, pool, companyID)
	return res.Cleared, err
}

// RepairWeakEnhanceHashesDetailed is RepairWeakEnhanceHashes plus scan/raw-id detail
// for admin Fix A1 hygiene reporting.
func RepairWeakEnhanceHashesDetailed(ctx context.Context, pool *pgxpool.Pool, companyID uuid.UUID) (RepairWeakEnhanceHashesResult, error) {
	var out RepairWeakEnhanceHashesResult
	if pool == nil {
		return out, fmt.Errorf("catalog pool not configured")
	}
	if companyID == uuid.Nil {
		return out, ClientMsg("company_id is required")
	}
	tx, err := pool.Begin(ctx)
	if err != nil {
		return out, err
	}
	defer tx.Rollback(ctx)

	out, err = repairWeakEnhanceHashesTx(ctx, tx, companyID)
	if err != nil {
		return out, err
	}
	if err := tx.Commit(ctx); err != nil {
		return out, err
	}
	return out, nil
}

// RepairWeakEnhanceHashes clears weak enhance skip hashes for the company.
func (s *Service) RepairWeakEnhanceHashes(ctx context.Context, companyID uuid.UUID) (int64, error) {
	if s == nil || s.Pool == nil {
		return 0, fmt.Errorf("catalog service not configured")
	}
	return RepairWeakEnhanceHashes(ctx, s.Pool, companyID)
}

func repairWeakEnhanceHashesTx(ctx context.Context, tx pgx.Tx, companyID uuid.UUID) (RepairWeakEnhanceHashesResult, error) {
	var out RepairWeakEnhanceHashesResult
	rows, err := tx.Query(ctx, `
		SELECT id, raw_product_id,
			COALESCE(name, ''),
			COALESCE(description, ''),
			COALESCE(processed_name, ''),
			COALESCE(processed_description, ''),
			COALESCE(field_sources, '{}'::jsonb),
			COALESCE(localized_content, '{}'::jsonb)
		FROM processed_products
		WHERE company_id = $1`, companyID)
	if err != nil {
		return out, fmt.Errorf("list processed products: %w", err)
	}
	defer rows.Close()

	type pending struct {
		id    uuid.UUID
		rawID uuid.UUID
		fs    []byte
		loc   []byte
	}
	var updates []pending

	for rows.Next() {
		out.Scanned++
		var (
			id, rawID                                uuid.UUID
			name, desc, processedName, processedDesc string
			fsRaw, locRaw                            []byte
		)
		if err := rows.Scan(&id, &rawID, &name, &desc, &processedName, &processedDesc, &fsRaw, &locRaw); err != nil {
			return out, err
		}
		fs := map[string]any{}
		if len(fsRaw) > 0 {
			if err := json.Unmarshal(fsRaw, &fs); err != nil {
				return out, err
			}
		}
		if fs == nil {
			fs = map[string]any{}
		}
		loc, err := company.DecodeLocalizedContent(locRaw)
		if err != nil {
			return out, err
		}

		changed := false
		primaryDesc := strings.TrimSpace(processedDesc)
		if primaryDesc == "" {
			primaryDesc = desc
		}
		primaryName := strings.TrimSpace(processedName)
		if primaryName == "" {
			primaryName = name
		}

		if _, has := fs[enhanceInputHashKey]; has {
			if company.ShouldRefuseEnhanceHashSkip(primaryDesc, primaryName, name) {
				delete(fs, enhanceInputHashKey)
				changed = true
			}
		}

		for lang, fields := range loc {
			d := strings.TrimSpace(fields.ProcessedDescription)
			n := strings.TrimSpace(fields.ProcessedName)
			if n == "" {
				n = primaryName
			}
			if strings.TrimSpace(fields.EnhanceInputHash) == "" {
				continue
			}
			if company.ShouldRefuseEnhanceHashSkip(d, n, primaryName, name) {
				fields.EnhanceInputHash = ""
				loc[lang] = fields
				changed = true
			}
		}

		if !changed {
			continue
		}
		fsBytes, err := json.Marshal(fs)
		if err != nil {
			return out, err
		}
		locBytes, err := company.EncodeLocalizedContent(loc)
		if err != nil {
			return out, err
		}
		updates = append(updates, pending{id: id, rawID: rawID, fs: fsBytes, loc: locBytes})
	}
	if err := rows.Err(); err != nil {
		return out, err
	}
	rows.Close()

	seenRaw := map[uuid.UUID]struct{}{}
	for _, u := range updates {
		ct, err := tx.Exec(ctx, `
			UPDATE processed_products
			SET field_sources = $2::jsonb,
			    localized_content = $3::jsonb,
			    updated_at = now()
			WHERE id = $1 AND company_id = $4`,
			u.id, u.fs, u.loc, companyID)
		if err != nil {
			return out, fmt.Errorf("clear enhance hashes product=%s: %w", u.id, err)
		}
		if ct.RowsAffected() > 0 {
			out.Cleared++
			if _, ok := seenRaw[u.rawID]; !ok {
				seenRaw[u.rawID] = struct{}{}
				out.ClearedRawIDs = append(out.ClearedRawIDs, u.rawID)
			}
		}
	}
	return out, nil
}