package handlers

import (
	"fmt"
	"net/http"
)

// ==============================================================================
// REQUEST/RESPONSE TYPES
// Structured types for common request patterns with validation
// ==============================================================================

// LanguageRequest represents a request with language parameter
type LanguageRequest struct {
	Lang string `validate:"required,oneof=en es"`
}

// ParseLanguageRequest parses and validates language from query parameters
func ParseLanguageRequest(r *http.Request) (*LanguageRequest, error) {
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = "en"
	}

	// Validate language
	if lang != "en" && lang != "es" {
		return nil, fmt.Errorf("unsupported language: %s (use 'en' or 'es')", lang)
	}

	return &LanguageRequest{Lang: lang}, nil
}

// PDFExportRequest represents all parameters for PDF export
type PDFExportRequest struct {
	Lang    string `validate:"required,oneof=en es"`                   // Language: "en" or "es"
	Length  string `validate:"required,oneof=short long"`              // Length: "short" or "long"
	Icons   string `validate:"required,oneof=show hide"`               // Icons: "show" or "hide"
	Version string `validate:"required,oneof=with_skills clean"`       // Version: "with_skills" or "clean"
}

// ParsePDFExportRequest parses and validates PDF export parameters
func ParsePDFExportRequest(r *http.Request) (*PDFExportRequest, error) {
	req := &PDFExportRequest{
		Lang:    r.URL.Query().Get("lang"),
		Length:  r.URL.Query().Get("length"),
		Icons:   r.URL.Query().Get("icons"),
		Version: r.URL.Query().Get("version"),
	}

	// Set defaults
	if req.Lang == "" {
		req.Lang = "en"
	}
	if req.Length == "" {
		req.Length = "short"
	}
	if req.Icons == "" {
		req.Icons = "show"
	}
	if req.Version == "" {
		req.Version = "with_skills"
	}

	// Validate language
	if req.Lang != "en" && req.Lang != "es" {
		return nil, fmt.Errorf("unsupported language: %s (use 'en' or 'es')", req.Lang)
	}

	// Validate length
	if req.Length != "short" && req.Length != "long" {
		return nil, fmt.Errorf("unsupported length: %s (use 'short' or 'long')", req.Length)
	}

	// Validate icons
	if req.Icons != "show" && req.Icons != "hide" {
		return nil, fmt.Errorf("unsupported icons option: %s (use 'show' or 'hide')", req.Icons)
	}

	// Validate version
	if req.Version != "with_skills" && req.Version != "clean" {
		return nil, fmt.Errorf("unsupported version: %s (use 'with_skills' or 'clean')", req.Version)
	}

	return req, nil
}

// PreferenceToggleRequest represents a toggle request with language context
type PreferenceToggleRequest struct {
	Lang string // Current language from query or cookie
}

// ParsePreferenceToggleRequest parses toggle request parameters
func ParsePreferenceToggleRequest(r *http.Request, defaultLang string) *PreferenceToggleRequest {
	lang := r.URL.Query().Get("lang")
	if lang == "" {
		lang = defaultLang
	}

	return &PreferenceToggleRequest{Lang: lang}
}

// ==============================================================================
// RESPONSE TYPES
// Structured response types for consistent API responses
// ==============================================================================

// APIResponse is a standardized response wrapper for JSON responses
type APIResponse struct {
	Success bool        `json:"success"`
	Data    interface{} `json:"data,omitempty"`
	Error   *ErrorInfo  `json:"error,omitempty"`
	Meta    *MetaInfo   `json:"meta,omitempty"`
}

// ErrorInfo provides structured error information
type ErrorInfo struct {
	Code    string `json:"code"`              // Error code (e.g., "INVALID_LANGUAGE")
	Message string `json:"message"`           // Human-readable error message
	Field   string `json:"field,omitempty"`   // Field that caused the error
	Details string `json:"details,omitempty"` // Additional error details
}

// MetaInfo provides metadata about the response
type MetaInfo struct {
	Timestamp int64  `json:"timestamp,omitempty"` // Unix timestamp
	Version   string `json:"version,omitempty"`   // API version
	RequestID string `json:"request_id,omitempty"` // Request tracking ID
}

// SuccessResponse creates a success response
func SuccessResponse(data interface{}) *APIResponse {
	return &APIResponse{
		Success: true,
		Data:    data,
	}
}

// NewErrorResponse creates an error response
func NewErrorResponse(code, message string) *APIResponse {
	return &APIResponse{
		Success: false,
		Error: &ErrorInfo{
			Code:    code,
			Message: message,
		},
	}
}

// ErrorResponseWithField creates an error response with field information
func ErrorResponseWithField(code, message, field string) *APIResponse {
	return &APIResponse{
		Success: false,
		Error: &ErrorInfo{
			Code:    code,
			Message: message,
			Field:   field,
		},
	}
}

// HealthCheckResponse represents health check endpoint response
type HealthCheckResponse struct {
	Status  string `json:"status"`            // "healthy" or "unhealthy"
	Version string `json:"version"`           // Application version
	Uptime  int64  `json:"uptime,omitempty"`  // Uptime in seconds
	Checks  map[string]bool `json:"checks,omitempty"` // Component health checks
}