package company

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

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

// LangPromptMap is language-code → prompt text for category / template overrides.
type LangPromptMap map[string]string

// LocalizedFields holds AI/output fields for one content language.
type LocalizedFields struct {
	ProcessedName        string `json:"processed_name,omitempty"`
	ProcessedDescription string `json:"processed_description,omitempty"`
	MetaTitle            string `json:"meta_title,omitempty"`
	MetaDescription      string `json:"meta_description,omitempty"`
	EnhanceInputHash     string `json:"enhance_input_hash,omitempty"`
}

// LocalizedContent is language-code → per-language product output fields.
type LocalizedContent map[string]LocalizedFields

// SanitizeLangPromptMap validates language codes, sanitizes prompts, and drops empties.
func SanitizeLangPromptMap(in map[string]string, maxRunes int) (LangPromptMap, error) {
	out := make(LangPromptMap)
	if len(in) == 0 {
		return out, nil
	}
	for lang, prompt := range in {
		code, err := ParseLanguage(lang, false)
		if err != nil {
			return nil, fmt.Errorf("unsupported language %q", lang)
		}
		p := strings.TrimSpace(security.SanitizePrompt(prompt, maxRunes))
		if p == "" {
			continue
		}
		out[code] = p
	}
	return out, nil
}

// PromptForLanguage returns the prompt for lang, or empty if unset.
func PromptForLanguage(m LangPromptMap, lang string) string {
	if len(m) == 0 {
		return ""
	}
	code, err := ParseLanguage(lang, true)
	if err != nil {
		code = DefaultLanguage
	}
	return strings.TrimSpace(m[code])
}

// HasAnyPrompt reports whether any language has a non-empty prompt.
func HasAnyPrompt(m LangPromptMap) bool {
	for _, p := range m {
		if strings.TrimSpace(p) != "" {
			return true
		}
	}
	return false
}

// DecodeLangPromptMap accepts JSON object / map[string]any / map[string]string.
func DecodeLangPromptMap(raw any) (LangPromptMap, error) {
	out := make(LangPromptMap)
	if raw == nil {
		return out, nil
	}
	switch v := raw.(type) {
	case LangPromptMap:
		return SanitizeLangPromptMap(v, security.MaxCampaignPromptRunes)
	case map[string]string:
		return SanitizeLangPromptMap(v, security.MaxCampaignPromptRunes)
	case map[string]any:
		tmp := make(map[string]string, len(v))
		for k, val := range v {
			s, ok := val.(string)
			if !ok {
				return nil, fmt.Errorf("prompt for %q must be a string", k)
			}
			tmp[k] = s
		}
		return SanitizeLangPromptMap(tmp, security.MaxCampaignPromptRunes)
	case string:
		s := strings.TrimSpace(v)
		if s == "" || s == "{}" {
			return out, nil
		}
		var obj map[string]string
		if err := json.Unmarshal([]byte(s), &obj); err != nil {
			return nil, fmt.Errorf("invalid prompt map json")
		}
		return SanitizeLangPromptMap(obj, security.MaxCampaignPromptRunes)
	case []byte:
		if len(v) == 0 {
			return out, nil
		}
		var obj map[string]string
		if err := json.Unmarshal(v, &obj); err != nil {
			return nil, fmt.Errorf("invalid prompt map json")
		}
		return SanitizeLangPromptMap(obj, security.MaxCampaignPromptRunes)
	default:
		b, err := json.Marshal(raw)
		if err != nil {
			return nil, fmt.Errorf("invalid prompt map")
		}
		var obj map[string]string
		if err := json.Unmarshal(b, &obj); err != nil {
			return nil, fmt.Errorf("invalid prompt map json")
		}
		return SanitizeLangPromptMap(obj, security.MaxCampaignPromptRunes)
	}
}

// EncodeLangPromptMap marshals a prompt map to JSON bytes (never null).
func EncodeLangPromptMap(m LangPromptMap) ([]byte, error) {
	if m == nil {
		return []byte("{}"), nil
	}
	b, err := json.Marshal(m)
	if err != nil {
		return nil, err
	}
	return b, nil
}

// ParseContentLanguages validates and normalizes an ordered language list.
// Empty input with allowEmptyAsPrimary yields [DefaultLanguage] or [primary] when primary set.
func ParseContentLanguages(raw []string, primary string) ([]string, error) {
	primaryCode, err := ParseLanguage(primary, true)
	if err != nil {
		primaryCode = DefaultLanguage
	}
	seen := map[string]struct{}{}
	out := make([]string, 0, len(raw)+1)
	add := func(code string) {
		if _, ok := seen[code]; ok {
			return
		}
		seen[code] = struct{}{}
		out = append(out, code)
	}
	add(primaryCode)
	for _, r := range raw {
		code, err := ParseLanguage(r, false)
		if err != nil {
			return nil, fmt.Errorf("unsupported language %q", r)
		}
		add(code)
	}
	return out, nil
}

// LoadContentLanguages returns companies.content_languages, ensuring primary is first.
func LoadContentLanguages(ctx context.Context, pool *pgxpool.Pool, companyID uuid.UUID) []string {
	primary := LoadLanguage(ctx, pool, companyID)
	if pool == nil {
		return []string{primary}
	}
	var langs []string
	err := pool.QueryRow(ctx, `
		SELECT COALESCE(content_languages, '{}') FROM companies WHERE id = $1`, companyID).Scan(&langs)
	if err != nil || len(langs) == 0 {
		return []string{primary}
	}
	parsed, err := ParseContentLanguages(langs, primary)
	if err != nil {
		return []string{primary}
	}
	return parsed
}

// FieldsForLanguage returns localized fields for lang (empty struct if missing).
func FieldsForLanguage(content LocalizedContent, lang string) LocalizedFields {
	if len(content) == 0 {
		return LocalizedFields{}
	}
	code, err := ParseLanguage(lang, true)
	if err != nil {
		code = DefaultLanguage
	}
	return content[code]
}

// SetFieldsForLanguage upserts fields for one language into content.
func SetFieldsForLanguage(content LocalizedContent, lang string, fields LocalizedFields) LocalizedContent {
	if content == nil {
		content = LocalizedContent{}
	}
	code, err := ParseLanguage(lang, true)
	if err != nil {
		code = DefaultLanguage
	}
	content[code] = fields
	return content
}

// DecodeLocalizedContent parses JSONB / map into LocalizedContent.
func DecodeLocalizedContent(raw any) (LocalizedContent, error) {
	out := LocalizedContent{}
	if raw == nil {
		return out, nil
	}
	var b []byte
	switch v := raw.(type) {
	case []byte:
		b = v
	case string:
		b = []byte(v)
	default:
		var err error
		b, err = json.Marshal(raw)
		if err != nil {
			return nil, err
		}
	}
	if len(b) == 0 || string(b) == "null" || string(b) == "{}" {
		return out, nil
	}
	var tmp map[string]LocalizedFields
	if err := json.Unmarshal(b, &tmp); err != nil {
		return nil, fmt.Errorf("invalid localized_content")
	}
	for lang, fields := range tmp {
		code, err := ParseLanguage(lang, false)
		if err != nil {
			continue
		}
		out[code] = fields
	}
	return out, nil
}

// EncodeLocalizedContent marshals localized content (never null).
func EncodeLocalizedContent(c LocalizedContent) ([]byte, error) {
	if c == nil {
		return []byte("{}"), nil
	}
	return json.Marshal(c)
}

// SyncPrimaryFromLocalized copies primary-language fields onto the denormalized columns shape.
func SyncPrimaryFromLocalized(content LocalizedContent, primary string) LocalizedFields {
	return FieldsForLanguage(content, primary)
}