package kanban

import (
	"net/http"
	"strconv"
	"tm/pkg/response"

	"github.com/labstack/echo/v4"
)

// Handler handles kanban HTTP requests
type Handler struct {
	service Service
}

// NewHandler creates a new kanban handler
func NewHandler(service Service) *Handler {
	return &Handler{
		service: service,
	}
}

// RegisterRoutes registers kanban routes on the Echo group passed by the caller.
// The caller MUST mount a /kanban subgroup first (e.g. adminV1.Group("/kanban") or v1.Group("/kanban"))
// so paths resolve to .../kanban/boards, not .../boards.
func (h *Handler) RegisterRoutes(router *echo.Group) {
	router.POST("/boards", h.CreateBoard)
	router.GET("/boards", h.GetBoardsByUser)
	router.GET("/boards/default", h.GetDefaultBoard)
	router.GET("/boards/:id", h.GetBoardByID)
	router.PUT("/boards/:id", h.UpdateBoard)
	router.DELETE("/boards/:id", h.DeleteBoard)

	router.POST("/columns", h.CreateColumn)
	router.PUT("/columns/:id", h.UpdateColumn)
	router.DELETE("/columns/:id", h.DeleteColumn)
	router.PUT("/columns/reorder", h.ReorderColumns)

	router.POST("/cards", h.CreateCard)
	router.GET("/cards/:id", h.GetCardByID)
	router.PUT("/cards/:id", h.UpdateCard)
	router.DELETE("/cards/:id", h.DeleteCard)
	router.PUT("/cards/move", h.MoveCard)
	router.PUT("/cards/reorder", h.ReorderCards)
}

// CreateBoard creates a new kanban board
// @Summary Create a new kanban board
// @Description Create a new kanban board with the provided information
// @Tags kanban
// @Accept json
// @Produce json
// @Param board body CreateBoardRequest true "Board information"
// @Success 201 {object} response.Response{data=BoardResponse}
// @Failure 400 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/boards [post]
func (h *Handler) CreateBoard(c echo.Context) error {
	var req CreateBoardRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}
	req.UserID = ownerID

	board, err := h.service.CreateBoard(c.Request().Context(), req)
	if err := handleServiceError(c, err, "Failed to create board"); err != nil {
		return err
	}

	return response.Created(c, board, "Board created successfully")
}

// GetBoardByID retrieves a board by ID
// @Summary Get a kanban board by ID
// @Description Retrieve a kanban board with all its columns and cards
// @Tags kanban
// @Accept json
// @Produce json
// @Param id path string true "Board ID"
// @Success 200 {object} response.Response{data=BoardDetailResponse}
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/boards/{id} [get]
func (h *Handler) GetBoardByID(c echo.Context) error {
	id := c.Param("id")

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	board, err := h.service.GetBoardByID(c.Request().Context(), id, ownerID)
	if err := handleServiceError(c, err, "Failed to get board"); err != nil {
		return err
	}

	return response.Success(c, board, "Board retrieved successfully")
}

// GetBoardsByUser retrieves all boards for the authenticated user
// @Summary Get all kanban boards for user
// @Description Retrieve all kanban boards belonging to the authenticated user
// @Tags kanban
// @Accept json
// @Produce json
// @Success 200 {object} response.Response{data=BoardsListResponse}
// @Failure 500 {object} response.Response
// @Router /kanban/boards [get]
func (h *Handler) GetBoardsByUser(c echo.Context) error {
	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	boards, err := h.service.GetBoardsByUserID(c.Request().Context(), ownerID)
	if err := handleServiceError(c, err, "Failed to get boards"); err != nil {
		return err
	}

	return response.Success(c, boards, "Boards retrieved successfully")
}

// GetDefaultBoard retrieves the default board for the authenticated user
// @Summary Get default kanban board
// @Description Retrieve the default kanban board for the authenticated user
// @Tags kanban
// @Accept json
// @Produce json
// @Success 200 {object} response.Response{data=BoardDetailResponse}
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/boards/default [get]
func (h *Handler) GetDefaultBoard(c echo.Context) error {
	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	board, err := h.service.GetDefaultBoard(c.Request().Context(), ownerID)
	if err := handleServiceError(c, err, "Failed to get default board"); err != nil {
		return err
	}

	return response.Success(c, board, "Default board retrieved successfully")
}

// UpdateBoard updates an existing board
// @Summary Update a kanban board
// @Description Update an existing kanban board with the provided information
// @Tags kanban
// @Accept json
// @Produce json
// @Param id path string true "Board ID"
// @Param board body UpdateBoardRequest true "Board update information"
// @Success 200 {object} response.Response{data=BoardResponse}
// @Failure 400 {object} response.Response
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/boards/{id} [put]
func (h *Handler) UpdateBoard(c echo.Context) error {
	var req UpdateBoardRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	req.ID = c.Param("id")

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	board, err := h.service.UpdateBoard(c.Request().Context(), req, ownerID)
	if err := handleServiceError(c, err, "Failed to update board"); err != nil {
		return err
	}

	return response.Success(c, board, "Board updated successfully")
}

// DeleteBoard deletes a board
// @Summary Delete a kanban board
// @Description Delete a kanban board and all its columns and cards
// @Tags kanban
// @Accept json
// @Produce json
// @Param id path string true "Board ID"
// @Success 204 {object} response.Response
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/boards/{id} [delete]
func (h *Handler) DeleteBoard(c echo.Context) error {
	id := c.Param("id")

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	if err := h.service.DeleteBoard(c.Request().Context(), id, ownerID); err != nil {
		return handleServiceError(c, err, "Failed to delete board")
	}

	return c.NoContent(http.StatusNoContent)
}

// CreateColumn creates a new column
// @Summary Create a new column
// @Description Create a new column in a kanban board
// @Tags kanban
// @Accept json
// @Produce json
// @Param column body CreateColumnRequest true "Column information"
// @Success 201 {object} response.Response{data=ColumnResponse}
// @Failure 400 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/columns [post]
func (h *Handler) CreateColumn(c echo.Context) error {
	var req CreateColumnRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	column, err := h.service.CreateColumn(c.Request().Context(), req, ownerID)
	if err := handleServiceError(c, err, "Failed to create column"); err != nil {
		return err
	}

	return response.Created(c, column, "Column created successfully")
}

// UpdateColumn updates an existing column
// @Summary Update a column
// @Description Update an existing column in a kanban board
// @Tags kanban
// @Accept json
// @Produce json
// @Param id path string true "Column ID"
// @Param column body UpdateColumnRequest true "Column update information"
// @Success 200 {object} response.Response{data=ColumnResponse}
// @Failure 400 {object} response.Response
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/columns/{id} [put]
func (h *Handler) UpdateColumn(c echo.Context) error {
	var req UpdateColumnRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	req.ID = c.Param("id")

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	column, err := h.service.UpdateColumn(c.Request().Context(), req, ownerID)
	if err := handleServiceError(c, err, "Failed to update column"); err != nil {
		return err
	}

	return response.Success(c, column, "Column updated successfully")
}

// DeleteColumn deletes a column
// @Summary Delete a column
// @Description Delete a column and move its cards to the next column
// @Tags kanban
// @Accept json
// @Produce json
// @Param id path string true "Column ID"
// @Success 204 {object} response.Response
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/columns/{id} [delete]
func (h *Handler) DeleteColumn(c echo.Context) error {
	id := c.Param("id")

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	if err := h.service.DeleteColumn(c.Request().Context(), id, ownerID); err != nil {
		return handleServiceError(c, err, "Failed to delete column")
	}

	return c.NoContent(http.StatusNoContent)
}

// ReorderColumns reorders columns within a board
// @Summary Reorder columns
// @Description Reorder columns within a kanban board
// @Tags kanban
// @Accept json
// @Produce json
// @Param reorder body ReorderColumnsRequest true "Column reorder information"
// @Success 200 {object} response.Response
// @Failure 400 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/columns/reorder [put]
func (h *Handler) ReorderColumns(c echo.Context) error {
	var req ReorderColumnsRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	if err := h.service.ReorderColumns(c.Request().Context(), req, ownerID); err != nil {
		return handleServiceError(c, err, "Failed to reorder columns")
	}

	return response.Success(c, map[string]string{"message": "Columns reordered successfully"}, "Columns reordered successfully")
}

// CreateCard creates a new card
// @Summary Create a new card
// @Description Create a new card in a kanban column
// @Tags kanban
// @Accept json
// @Produce json
// @Param card body CreateCardRequest true "Card information"
// @Success 201 {object} response.Response{data=CardResponse}
// @Failure 400 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/cards [post]
func (h *Handler) CreateCard(c echo.Context) error {
	var req CreateCardRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	// Set default priority if not provided
	if req.Priority == "" {
		req.Priority = CardPriorityMedium
	}

	// Parse order from query param if provided
	if orderStr := c.QueryParam("order"); orderStr != "" {
		if order, err := strconv.Atoi(orderStr); err == nil {
			req.Order = order
		}
	}

	// Parse due_date from query param if provided
	if dueDateStr := c.QueryParam("due_date"); dueDateStr != "" {
		if dueDate, err := strconv.ParseInt(dueDateStr, 10, 64); err == nil {
			req.DueDate = &dueDate
		}
	}

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	card, err := h.service.CreateCard(c.Request().Context(), req, ownerID)
	if err := handleServiceError(c, err, "Failed to create card"); err != nil {
		return err
	}

	return response.Created(c, card, "Card created successfully")
}

// GetCardByID retrieves a card by ID
// @Summary Get a card by ID
// @Description Retrieve a kanban card by its ID
// @Tags kanban
// @Accept json
// @Produce json
// @Param id path string true "Card ID"
// @Success 200 {object} response.Response{data=CardResponse}
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/cards/{id} [get]
func (h *Handler) GetCardByID(c echo.Context) error {
	id := c.Param("id")

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	card, err := h.service.GetCardByID(c.Request().Context(), id, ownerID)
	if err := handleServiceError(c, err, "Failed to get card"); err != nil {
		return err
	}

	return response.Success(c, card, "Card retrieved successfully")
}

// UpdateCard updates an existing card
// @Summary Update a card
// @Description Update an existing kanban card
// @Tags kanban
// @Accept json
// @Produce json
// @Param id path string true "Card ID"
// @Param card body UpdateCardRequest true "Card update information"
// @Success 200 {object} response.Response{data=CardResponse}
// @Failure 400 {object} response.Response
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/cards/{id} [put]
func (h *Handler) UpdateCard(c echo.Context) error {
	var req UpdateCardRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	req.ID = c.Param("id")

	// Parse due_date from query param if provided
	if dueDateStr := c.QueryParam("due_date"); dueDateStr != "" {
		if dueDate, err := strconv.ParseInt(dueDateStr, 10, 64); err == nil {
			req.DueDate = &dueDate
		}
	}

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	card, err := h.service.UpdateCard(c.Request().Context(), req, ownerID)
	if err := handleServiceError(c, err, "Failed to update card"); err != nil {
		return err
	}

	return response.Success(c, card, "Card updated successfully")
}

// DeleteCard deletes a card
// @Summary Delete a card
// @Description Delete a kanban card
// @Tags kanban
// @Accept json
// @Produce json
// @Param id path string true "Card ID"
// @Success 204 {object} response.Response
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/cards/{id} [delete]
func (h *Handler) DeleteCard(c echo.Context) error {
	id := c.Param("id")

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	if err := h.service.DeleteCard(c.Request().Context(), id, ownerID); err != nil {
		return handleServiceError(c, err, "Failed to delete card")
	}

	return c.NoContent(http.StatusNoContent)
}

// MoveCard moves a card to a different column
// @Summary Move a card
// @Description Move a kanban card to a different column
// @Tags kanban
// @Accept json
// @Produce json
// @Param move body MoveCardRequest true "Card move information"
// @Success 200 {object} response.Response
// @Failure 400 {object} response.Response
// @Failure 404 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/cards/move [put]
func (h *Handler) MoveCard(c echo.Context) error {
	var req MoveCardRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	if err := h.service.MoveCard(c.Request().Context(), req, ownerID); err != nil {
		return handleServiceError(c, err, "Failed to move card")
	}

	return response.Success(c, map[string]string{"message": "Card moved successfully"}, "Card moved successfully")
}

// ReorderCards reorders cards within a column
// @Summary Reorder cards
// @Description Reorder cards within a kanban column
// @Tags kanban
// @Accept json
// @Produce json
// @Param reorder body ReorderCardsRequest true "Card reorder information"
// @Success 200 {object} response.Response
// @Failure 400 {object} response.Response
// @Failure 500 {object} response.Response
// @Router /kanban/cards/reorder [put]
func (h *Handler) ReorderCards(c echo.Context) error {
	var req ReorderCardsRequest
	if err := c.Bind(&req); err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	ownerID, exists := ownerIDFromContext(c)
	if !exists {
		return response.Unauthorized(c, "User not authenticated")
	}

	if err := h.service.ReorderCards(c.Request().Context(), req, ownerID); err != nil {
		return handleServiceError(c, err, "Failed to reorder cards")
	}

	return response.Success(c, map[string]string{"message": "Cards reordered successfully"}, "Cards reordered successfully")
}