package catalog

import (
	"context"
	"fmt"
	"strings"

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

// Canonical Postgres id for the migrated A1 Slovenija tenant (seed-a1 default).
const a1CompanyID = "604f23a8-b66e-4b21-8b45-0d72b68f4790"

// platformDemoCompanyName matches migrator / seed-demo standalone demo tenant.
const platformDemoCompanyName = "Platform Demo"

// RepairCategoryEnhancePromptsResult is the dry-run / apply summary for
// RepairA1DemoCategoryEnhancePrompts.
type RepairCategoryEnhancePromptsResult struct {
	CompaniesScanned int            `json:"companies_scanned"`
	CategoriesSeen   int            `json:"categories_seen"`
	WouldUpdate      int            `json:"would_update"`
	Updated          int            `json:"updated"`
	AlreadyOK        int            `json:"already_ok"`
	EmptySkipped     int            `json:"empty_skipped"`
	ByCompany        map[string]int `json:"by_company"`
	DryRun           bool           `json:"dry_run"`
}

// RepairA1DemoCategoryEnhancePrompts replaces legacy HTML marketing categories.prompt
// values for A1 Slovenija + Platform Demo with aiprompts.CategoryEnhanceUserTemplate
// (role-sectioned title/description/meta/attributes USER overlay).
//
// LOCAL repair only (idempotent):
//   - Writes JSON-compatible user overlays under both "sl" (prompt->>'sl') and "*"
//     (LangPromptAny) so language stays via {{language}}, not hardcoded-only copy.
//   - Touches ONLY categories.prompt — never title_template / description_template
//     (unique name/description/meta formulas stay intact; AppendFormulaConstraints
//     encodes them as plain-text instructions at enhance render time).
//   - dryRun=true: count WouldUpdate only; dryRun=false: apply and set Updated.
//
// Entrypoint: go run ./cmd/repair-category-prompts (-dry-run | -apply).
func RepairA1DemoCategoryEnhancePrompts(ctx context.Context, pool *pgxpool.Pool, dryRun bool) (RepairCategoryEnhancePromptsResult, error) {
	out := RepairCategoryEnhancePromptsResult{
		DryRun:    dryRun,
		ByCompany: map[string]int{},
	}
	if pool == nil {
		return out, fmt.Errorf("postgres pool is required")
	}

	a1ID, err := uuid.Parse(a1CompanyID)
	if err != nil {
		return out, fmt.Errorf("a1 company id: %w", err)
	}

	companyRows, err := pool.Query(ctx, `
		SELECT id, name
		FROM companies
		WHERE id = $1
		   OR name = $2
		   OR COALESCE(legacy_company_id, '') = $3
		ORDER BY name`, a1ID, platformDemoCompanyName, billing.A1LegacyCompanyID)
	if err != nil {
		return out, fmt.Errorf("list target companies: %w", err)
	}
	defer companyRows.Close()

	type co struct {
		id   uuid.UUID
		name string
	}
	companies := make([]co, 0, 2)
	for companyRows.Next() {
		var c co
		if err := companyRows.Scan(&c.id, &c.name); err != nil {
			return out, err
		}
		companies = append(companies, c)
	}
	if err := companyRows.Err(); err != nil {
		return out, err
	}
	out.CompaniesScanned = len(companies)
	if len(companies) == 0 {
		return out, fmt.Errorf("no A1 / Platform Demo companies found")
	}

	want, err := repairedCategoryEnhancePromptMap()
	if err != nil {
		return out, err
	}

	for _, c := range companies {
		n, err := repairCompanyCategoryEnhancePrompts(ctx, pool, c.id, c.name, want, dryRun, &out)
		if err != nil {
			return out, err
		}
		if n > 0 {
			out.ByCompany[c.name] = n
		}
	}
	return out, nil
}

// repairedCategoryEnhancePromptMap is the canonical stored shape: "sl" (prompt->>'sl'
// for A1/Demo) plus LangPromptAny ("*") so PromptForLanguage resolves for any content
// language. Copy stays language-agnostic via {{language}} — not hardcoded Slovenian.
func repairedCategoryEnhancePromptMap() (company.LangPromptMap, error) {
	tpl := strings.TrimSpace(aiprompts.CategoryEnhanceUserTemplate)
	if tpl == "" {
		return nil, fmt.Errorf("CategoryEnhanceUserTemplate is empty")
	}
	return company.LangPromptMap{
		"sl":                  tpl,
		company.LangPromptAny: tpl,
	}, nil
}

func categoryEnhancePromptMapOK(m company.LangPromptMap, want company.LangPromptMap) bool {
	if !company.HasAnyPrompt(m) || !company.HasAnyPrompt(want) {
		return false
	}
	tpl := strings.TrimSpace(want[company.LangPromptAny])
	if tpl == "" {
		tpl = strings.TrimSpace(want["sl"])
	}
	if tpl == "" {
		return false
	}
	// Accept already-repaired maps: every non-empty value equals the shared template
	// and LangPromptAny (or legacy sl-only) is present.
	hasKey := false
	for lang, p := range m {
		p = strings.TrimSpace(p)
		if p == "" {
			continue
		}
		if p != tpl {
			return false
		}
		if lang == company.LangPromptAny || lang == "sl" {
			hasKey = true
		}
	}
	return hasKey
}

func repairCompanyCategoryEnhancePrompts(
	ctx context.Context,
	pool *pgxpool.Pool,
	companyID uuid.UUID,
	companyName string,
	want company.LangPromptMap,
	dryRun bool,
	out *RepairCategoryEnhancePromptsResult,
) (int, error) {
	rows, err := pool.Query(ctx, `
		SELECT id, COALESCE(prompt, '{}'::jsonb)
		FROM categories
		WHERE company_id = $1`, companyID)
	if err != nil {
		return 0, fmt.Errorf("list categories for %s: %w", companyName, err)
	}
	defer rows.Close()

	updatedHere := 0
	for rows.Next() {
		var id uuid.UUID
		var raw []byte
		if err := rows.Scan(&id, &raw); err != nil {
			return updatedHere, err
		}
		out.CategoriesSeen++

		m, err := company.DecodeLangPromptMap(raw)
		if err != nil {
			return updatedHere, fmt.Errorf("decode prompt category=%s company=%s: %w", id, companyName, err)
		}
		if !company.HasAnyPrompt(m) {
			out.EmptySkipped++
			continue
		}
		if categoryEnhancePromptMapOK(m, want) {
			out.AlreadyOK++
			continue
		}

		out.WouldUpdate++
		if dryRun {
			updatedHere++
			continue
		}

		cleaned, err := company.SanitizeLangPromptMap(want, MaxCategoryPromptRunes)
		if err != nil {
			return updatedHere, fmt.Errorf("sanitize prompt category=%s: %w", id, err)
		}
		encoded, err := company.EncodeLangPromptMap(cleaned)
		if err != nil {
			return updatedHere, err
		}
		ct, err := pool.Exec(ctx, `
			UPDATE categories
			SET prompt = $3::jsonb, updated_at = now()
			WHERE id = $1 AND company_id = $2`, id, companyID, string(encoded))
		if err != nil {
			return updatedHere, fmt.Errorf("update prompt category=%s: %w", id, err)
		}
		if ct.RowsAffected() == 0 {
			return updatedHere, fmt.Errorf("category %s not updated (company mismatch?)", id)
		}
		out.Updated++
		updatedHere++
	}
	return updatedHere, rows.Err()
}