package processing

import (
	"context"

	"github.com/descrybe/descrybe-v2/apps/api/internal/company"
	"github.com/descrybe/descrybe-v2/apps/api/internal/eprel"
)

// Pipeline step names (canonical order for "full").
const (
	StepNormalize  = "normalize"
	StepParseSpecs = "parse_specs"
	StepFillFields = "fill_fields"
	StepEPREL      = "eprel"
	StepAIEnhance  = "ai_enhance"
)

// CanonicalSteps is the default full pipeline order.
var CanonicalSteps = []string{
	StepNormalize,
	StepParseSpecs,
	StepFillFields,
	StepEPREL,
	StepAIEnhance,
}

// Completer is the LLM chat boundary (OpenAI-compatible HTTP API).
type Completer interface {
	Complete(ctx context.Context, system, user string) (Completion, error)
}

// EnableChecker optionally reports whether a Completer should run.
type EnableChecker interface {
	Enabled() bool
}

// Completion is a single model response with usage for cost recording.
type Completion struct {
	Text         string
	PromptTokens int
	OutputTokens int
	TotalTokens  int
	Model        string
	Raw          any
}

// Embedder turns text into vectors (OpenAI-compatible /v1/embeddings).
// Used by vectorization / Pinecone paths; admin role: platformsettings.AIRoleVectorization.
type Embedder interface {
	Embed(ctx context.Context, texts []string) ([][]float32, error)
}

// VectorCategorizer optionally ranks categories by embedding similarity (Pinecone).
type VectorCategorizer interface {
	SuggestCategory(ctx context.Context, companyID, productText string, candidates []string) (string, error)
	Enabled() bool
}

// EPRELEnricher fetches EU energy-label data when an EPREL ID is present.
type EPRELEnricher interface {
	Enabled() bool
	Fetch(ctx context.Context, eprelID string) (*eprel.Data, error)
}

// ProductInput is sanitized product payload for pipeline steps.
type ProductInput struct {
	GTIN           string
	Name           string
	Description    string
	Mapped         map[string]any
	Raw            map[string]any
	StandardFields []StandardFieldDef
	// BrandPrompt is brand-kit guidance injected into AI enhance when non-empty
	// (paid plans only; Free may edit the kit but AI apply is gated).
	BrandPrompt string
	// Language is the primary content language (companies.language).
	Language string
	// ContentLanguages is the ordered list of languages to enhance (primary first).
	ContentLanguages []string
	// EnhanceByLang maps language → company/built-in system+user templates.
	EnhanceByLang map[string]PromptTemplates
	// EnhanceSystemTemplate / EnhanceUserTemplate are primary-language prompts
	// (kept for tests / single-lang callers).
	EnhanceSystemTemplate string
	EnhanceUserTemplate   string
	// CategoryEnhancePrompt overrides EnhanceUserTemplate when non-empty
	// (resolved for the active language before enhance).
	CategoryEnhancePrompt string
	// CategoryPromptsByLang maps lower(name) → lang → category override prompt.
	CategoryPromptsByLang map[string]company.LangPromptMap
	// Prior* are loaded from the last processed_products row for this raw product.
	PriorEnhanceHash          string
	PriorProcessedName        string
	PriorProcessedDescription string
	PriorCategory             string
	PriorLocalized            company.LocalizedContent
}

// PromptTemplates is a system+user pair for one language.
type PromptTemplates struct {
	System string
	User   string
}

// StepResult is the cumulative output for one product.
type StepResult struct {
	Category             string
	Name                 string
	Description          string
	ProcessedName        string
	ProcessedDescription string
	LocalizedContent     company.LocalizedContent
	Attributes           map[string]any
	ProcessedAttributes  map[string]any
	FieldSources         map[string]any
	EPREL                map[string]any
	GPTResponse          map[string]any
	TotalTokens          int
	// AIProviderMode is written to processed_products.ai_provider_mode /
	// processing_jobs.ai_provider_mode for analytics
	// ("internal" | "popular:<name>" | "custom" | "unknown").
	AIProviderMode string
	Notes          []string
	// SkipCreditDebit is set when AI enhance reused prior output because the
	// enhance input hash matched (ai_enhance_unchanged). processOne must not
	// ConsumeCredits in that case — no LLM and no meaningful rework.
	SkipCreditDebit bool
}

// StepProgress is a job-level snapshot of pipeline step status.
type StepProgress struct {
	Step   string `json:"step"`
	Status string `json:"status"` // pending|running|done|skipped|failed
	Note   string `json:"note,omitempty"`
}

// Engine runs ordered processing steps behind interfaces.
type Engine struct {
	Completer Completer
	Vector    VectorCategorizer
	EPREL     EPRELEnricher
	// ProviderMode is the analytics label for the active Completer:
	// "internal" | "popular:<name>" | "custom". Empty falls back to CompleterProviderMode.
	ProviderMode string
}

// CompleterEnabled reports whether AI enhance should run.
func (e *Engine) CompleterEnabled() bool {
	if e == nil || e.Completer == nil {
		return false
	}
	if c, ok := e.Completer.(EnableChecker); ok {
		return c.Enabled()
	}
	// HeuristicCompleter has no Enabled — treat as enabled only if explicitly set.
	// Worker sets Completer=nil when platform OpenAI (admin settings / env) is unset.
	_, isHeuristic := e.Completer.(HeuristicCompleter)
	return !isHeuristic
}