package handler

import (
	"errors"

	"accounting-app/pkg/api"
	"accounting-app/internal/service"

	"github.com/gin-gonic/gin"
)

// SettingsHandler handles HTTP requests for user settings operations
// Feature: accounting-feature-upgrade
// Validates: Requirements 5.4, 6.5, 8.25-8.27
type SettingsHandler struct {
	settingsService service.UserSettingsServiceInterface
}

// NewSettingsHandler creates a new SettingsHandler instance
func NewSettingsHandler(settingsService service.UserSettingsServiceInterface) *SettingsHandler {
	return &SettingsHandler{
		settingsService: settingsService,
	}
}

// GetSettings handles GET /api/v1/settings
// Retrieves user settings, creating default settings if not found
// Feature: accounting-feature-upgrade
// Validates: Requirements 5.4, 6.5, 8.25-8.27
func (h *SettingsHandler) GetSettings(c *gin.Context) {
	userId, exists := c.Get("user_id")
	if !exists {
		api.Unauthorized(c, "User not authenticated")
		return
	}

	settings, err := h.settingsService.GetSettings(userId.(uint))
	if err != nil {
		api.InternalError(c, "Failed to get settings: "+err.Error())
		return
	}

	api.Success(c, settings)
}

// UpdateSettings handles PUT /api/v1/settings
// Updates user settings with validation
// Feature: accounting-feature-upgrade
// Validates: Requirements 5.4, 6.5, 8.25-8.27
func (h *SettingsHandler) UpdateSettings(c *gin.Context) {
	userId, exists := c.Get("user_id")
	if !exists {
		api.Unauthorized(c, "User not authenticated")
		return
	}

	var input service.UserSettingsInput
	if err := c.ShouldBindJSON(&input); err != nil {
		api.ValidationError(c, "Invalid request body: "+err.Error())
		return
	}

	settings, err := h.settingsService.UpdateSettings(userId.(uint), input)
	if err != nil {
		if errors.Is(err, service.ErrInvalidIconLayout) {
			api.BadRequest(c, "Invalid icon layout, must be one of: four, five, six")
			return
		}
		if errors.Is(err, service.ErrInvalidImageCompression) {
			api.BadRequest(c, "Invalid image compression, must be one of: low, medium, high")
			return
		}
		api.InternalError(c, "Failed to update settings: "+err.Error())
		return
	}

	api.Success(c, settings)
}

// RegisterRoutes registers all settings routes to the given router group
func (h *SettingsHandler) RegisterRoutes(rg *gin.RouterGroup) {
	rg.GET("/settings", h.GetSettings)
	rg.PUT("/settings", h.UpdateSettings)
}