package handlers

import (
	"fmt"
	"net/http"

	"git.linuxforward.com/byop/byop-engine/dbstore"
	"git.linuxforward.com/byop/byop-engine/models"
	"github.com/gin-gonic/gin"
	"github.com/go-playground/validator/v10"
	"golang.org/x/crypto/bcrypt"
)

// UserHandler handles user-related operations
type UserHandler struct {
	Store    *dbstore.SQLiteStore
	Validate *validator.Validate
}

// NewUserHandler creates a new UserHandler
func NewUserHandler(store *dbstore.SQLiteStore) *UserHandler {
	return &UserHandler{
		Store:    store,
		Validate: validator.New(),
	}
}

// RegisterUserRoutes registers routes for user operations
func (h *UserHandler) RegisterUserRoutes(rg *gin.RouterGroup) {
	rg.POST("/", h.CreateUser)
	rg.GET("/:id", h.GetUser)
	rg.PUT("/:id", h.UpdateUser)
	rg.DELETE("/:id", h.DeleteUser)
	rg.GET("/", h.ListUsers)
	rg.GET("/:id/deployments", h.GetUserDeployments)
}

// CreateUserInput defines the input for creating a user
type CreateUserInput struct {
	Email    string `json:"email" validate:"required,email"`
	Password string `json:"password" validate:"required,min=8"`
	Name     string `json:"name" validate:"required,min=2"`
	Role     string `json:"role" validate:"omitempty,oneof=user admin editor"`
	Active   *bool  `json:"active"`
}

// CreateUser creates a new user
func (h *UserHandler) CreateUser(c *gin.Context) {
	ctx := c.Request.Context()
	var input CreateUserInput

	if err := c.ShouldBindJSON(&input); err != nil {
		appErr := models.NewErrValidation("invalid_user_input_format", map[string]string{"body": "Invalid request body"}, err)
		models.RespondWithError(c, appErr)
		return
	}

	if err := h.Validate.StructCtx(ctx, input); err != nil {
		errors := models.ExtractValidationErrors(err)
		appErr := models.NewErrValidation("user_validation_failed", errors, err)
		models.RespondWithError(c, appErr)
		return
	}

	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(input.Password), bcrypt.DefaultCost)
	if err != nil {
		appErr := models.NewErrInternalServer("password_hash_failed", fmt.Errorf("Failed to hash password: %w", err))
		models.RespondWithError(c, appErr)
		return
	}

	userRole := models.RoleUser
	if input.Role != "" {
		userRole = input.Role
	}

	userActive := true
	if input.Active != nil {
		userActive = *input.Active
	}

	user := models.User{
		Email:    input.Email,
		Password: string(hashedPassword),
		Name:     input.Name,
		Role:     userRole,
		Active:   userActive,
	}

	err = h.Store.CreateUser(ctx, &user)
	if err != nil {
		if models.IsErrConflict(err) {
			models.RespondWithError(c, err)
			return
		}
		appErr := models.NewErrInternalServer("failed_to_create_user", fmt.Errorf("Failed to create user: %w", err))
		models.RespondWithError(c, appErr)
		return
	}

	// GORM automatically sets the ID after creation
	// Clear the password before sending the response
	createdUser := user
	createdUser.Password = ""

	c.JSON(http.StatusCreated, createdUser)
}

// GetUser retrieves a user by ID
func (h *UserHandler) GetUser(c *gin.Context) {
	ctx := c.Request.Context()

	id, err := parseUintID(c, "id")
	if err != nil {
		models.RespondWithError(c, err)
		return
	}

	user, err := h.Store.GetUserByID(ctx, id)
	if err != nil {
		models.RespondWithError(c, err)
		return
	}

	user.Password = ""
	c.JSON(http.StatusOK, user)
}

// UpdateUserInput defines the input for updating a user
type UpdateUserInput struct {
	Email    *string `json:"email,omitempty" validate:"omitempty,email"`
	Password *string `json:"password,omitempty" validate:"omitempty,min=8"`
	Name     *string `json:"name,omitempty" validate:"omitempty,min=2"`
	Role     *string `json:"role,omitempty" validate:"omitempty,oneof=user admin editor"`
	Active   *bool   `json:"active,omitempty"`
}

// UpdateUser updates an existing user
func (h *UserHandler) UpdateUser(c *gin.Context) {
	ctx := c.Request.Context()

	id, err := parseUintID(c, "id")
	if err != nil {
		models.RespondWithError(c, err)
		return
	}

	var input UpdateUserInput
	if err := c.ShouldBindJSON(&input); err != nil {
		appErr := models.NewErrValidation("invalid_update_user_input_format", map[string]string{"body": "Invalid request body"}, err)
		models.RespondWithError(c, appErr)
		return
	}

	if err := h.Validate.StructCtx(ctx, input); err != nil {
		errors := models.ExtractValidationErrors(err)
		appErr := models.NewErrValidation("update_user_validation_failed", errors, err)
		models.RespondWithError(c, appErr)
		return
	}

	user, err := h.Store.GetUserByID(ctx, id)
	if err != nil {
		models.RespondWithError(c, err)
		return
	}

	updated := false
	if input.Email != nil {
		user.Email = *input.Email
		updated = true
	}
	if input.Password != nil {
		hashedPassword, err := bcrypt.GenerateFromPassword([]byte(*input.Password), bcrypt.DefaultCost)
		if err != nil {
			appErr := models.NewErrInternalServer("update_password_hash_failed", fmt.Errorf("Failed to hash new password: %w", err))
			models.RespondWithError(c, appErr)
			return
		}
		user.Password = string(hashedPassword)
		updated = true
	}
	if input.Name != nil {
		user.Name = *input.Name
		updated = true
	}
	if input.Role != nil {
		user.Role = *input.Role
		updated = true
	}
	if input.Active != nil {
		user.Active = *input.Active
		updated = true
	}

	if !updated {
		user.Password = ""
		c.JSON(http.StatusOK, user)
		return
	}

	if err := h.Store.UpdateUser(ctx, user); err != nil {
		models.RespondWithError(c, err)
		return
	}

	user.Password = ""
	c.JSON(http.StatusOK, user)
}

// DeleteUser deletes a user by ID
func (h *UserHandler) DeleteUser(c *gin.Context) {
	ctx := c.Request.Context()

	id, err := parseUintID(c, "id")
	if err != nil {
		models.RespondWithError(c, err)
		return
	}

	if err := h.Store.DeleteUser(ctx, id); err != nil {
		models.RespondWithError(c, err)
		return
	}

	c.Status(http.StatusNoContent)
}

// ListUsers retrieves all users
func (h *UserHandler) ListUsers(c *gin.Context) {
	ctx := c.Request.Context()

	users, err := h.Store.GetUsers(ctx)
	if err != nil {
		appErr := models.NewErrInternalServer("failed_to_list_users", fmt.Errorf("Failed to list users: %w", err))
		models.RespondWithError(c, appErr)
		return
	}

	for i := range users {
		users[i].Password = ""
	}

	c.JSON(http.StatusOK, users)
}

// GetUserDeployments returns all deployments for a specific user
func (h *UserHandler) GetUserDeployments(c *gin.Context) {
	ctx := c.Request.Context()

	userID, err := parseUintID(c, "id")
	if err != nil {
		models.RespondWithError(c, err)
		return
	}

	_, err = h.Store.GetUserByID(ctx, userID)
	if err != nil {
		models.RespondWithError(c, err)
		return
	}

	deployments, err := h.Store.GetDeploymentsByUserID(ctx, userID)
	if err != nil {
		appErr := models.NewErrInternalServer("failed_to_get_user_deployments", fmt.Errorf("Failed to get deployments for user %d: %w", userID, err))
		models.RespondWithError(c, appErr)
		return
	}

	if deployments == nil {
		deployments = []*models.Deployment{}
	}

	c.JSON(http.StatusOK, deployments)
}