package tender_submission

import (
	"errors"
	"strings"
	"tm/internal/customer"
	"tm/pkg/logger"
	"tm/pkg/response"

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

// Handler handles HTTP requests for tender submission operations.
type Handler struct {
	service Service
	logger  logger.Logger
}

func NewHandler(service Service, logger logger.Logger) *Handler {
	return &Handler{service: service, logger: logger}
}

// ListCompanySubmissions lists tender submissions for the authenticated company.
// @Summary List company tender submissions
// @Description Retrieve paginated tender submission workflows for the authenticated company
// @Tags TenderSubmissions
// @Accept json
// @Produce json
// @Param status query []string false "Filter by status"
// @Param stage query []string false "Filter by stage"
// @Param created_from query int false "Filter by created date from (Unix timestamp)"
// @Param created_to query int false "Filter by created date to (Unix timestamp)"
// @Param limit query int false "Page size (default 20, max 100)"
// @Param offset query int false "Pagination offset"
// @Success 200 {object} response.APIResponse{data=TenderSubmissionListResponse}
// @Failure 401 {object} response.APIResponse
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /api/v1/tender-submissions [get]
func (h *Handler) ListCompanySubmissions(c echo.Context) error {
	companyID, ok := c.Get("company_id").(string)
	if !ok || companyID == "" {
		return response.Unauthorized(c, "Unauthorized")
	}

	form, err := response.Parse[ListTenderSubmissionsForm](c)
	if err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	result, err := h.service.ListByCompanyWithTender(c.Request().Context(), companyID, form)
	if err != nil {
		return response.InternalServerError(c, "Failed to list tender submissions")
	}

	return response.SuccessWithMeta(c, result.Submissions, result.Metadata, "Tender submissions retrieved successfully")
}

// EnsureSubmission ensures a submission workflow exists for an approved tender.
// @Summary Ensure tender submission workflow
// @Description Create or return the submission workflow for an approved tender
// @Tags TenderSubmissions
// @Accept json
// @Produce json
// @Param tender_id path string true "Tender ID"
// @Success 200 {object} response.APIResponse{data=TenderSubmissionWithTenderResponse}
// @Failure 400 {object} response.APIResponse
// @Failure 404 {object} response.APIResponse
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /api/v1/tender-submissions/tender/{tender_id}/ensure [post]
func (h *Handler) EnsureSubmission(c echo.Context) error {
	companyID, err := h.resolveCompanyID(c)
	if err != nil {
		if errors.Is(err, customer.ErrCompanyNotAssigned) {
			return response.Forbidden(c, "Company is not assigned to customer")
		}
		return response.BadRequest(c, "Company ID is required", "")
	}

	customerID, _ := customer.GetCustomerIDFromContext(c)
	tenderID := strings.TrimSpace(c.Param("tender_id"))
	if tenderID == "" {
		return response.BadRequest(c, "Tender ID is required", "")
	}

	result, err := h.service.EnsureForApprovedTender(c.Request().Context(), tenderID, companyID, customerID)
	if err != nil {
		if errors.Is(err, ErrTenderNotFound) {
			return response.NotFound(c, "Tender not found")
		}
		if errors.Is(err, ErrApprovalRequired) {
			return response.BadRequest(c, "Tender must be approved before starting submission workflow", "")
		}
		return response.InternalServerError(c, "Failed to ensure tender submission")
	}

	return response.Success(c, result, "Tender submission ensured successfully")
}

// GetSubmissionByID retrieves a tender submission by ID for the authenticated company.
// @Summary Get tender submission by ID
// @Description Retrieve a tender submission workflow with tender details for the authenticated company
// @Tags TenderSubmissions
// @Accept json
// @Produce json
// @Param id path string true "Submission ID"
// @Success 200 {object} response.APIResponse{data=TenderSubmissionWithTenderResponse}
// @Failure 401 {object} response.APIResponse
// @Failure 404 {object} response.APIResponse
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /api/v1/tender-submissions/{id} [get]
func (h *Handler) GetSubmissionByID(c echo.Context) error {
	companyID, ok := c.Get("company_id").(string)
	if !ok || companyID == "" {
		return response.Unauthorized(c, "Unauthorized")
	}

	id := strings.TrimSpace(c.Param("id"))
	if id == "" {
		return response.BadRequest(c, "Submission ID is required", "")
	}

	result, err := h.service.GetByIDForCompanyWithTender(c.Request().Context(), id, companyID)
	if err != nil {
		if errors.Is(err, ErrTenderSubmissionNotFound) {
			return response.NotFound(c, "Tender submission not found")
		}
		return response.InternalServerError(c, "Failed to get tender submission")
	}

	return response.Success(c, result, "Tender submission retrieved successfully")
}

// GetSubmissionByTender retrieves a submission by tender and company.
// @Summary Get tender submission by tender
// @Description Retrieve the submission workflow for a specific tender and company
// @Tags TenderSubmissions
// @Accept json
// @Produce json
// @Param tender_id path string true "Tender ID"
// @Success 200 {object} response.APIResponse{data=TenderSubmissionWithTenderResponse}
// @Failure 404 {object} response.APIResponse
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /api/v1/tender-submissions/tender/{tender_id} [get]
func (h *Handler) GetSubmissionByTender(c echo.Context) error {
	companyID, ok := c.Get("company_id").(string)
	if !ok || companyID == "" {
		return response.Unauthorized(c, "Unauthorized")
	}

	tenderID := strings.TrimSpace(c.Param("tender_id"))
	if tenderID == "" {
		return response.BadRequest(c, "Tender ID is required", "")
	}

	result, err := h.service.GetByTenderAndCompanyWithTender(c.Request().Context(), tenderID, companyID)
	if err != nil {
		if errors.Is(err, ErrTenderNotFound) || errors.Is(err, ErrTenderSubmissionNotFound) {
			return response.NotFound(c, "Tender submission not found")
		}
		return response.InternalServerError(c, "Failed to get tender submission")
	}

	return response.Success(c, result, "Tender submission retrieved successfully")
}

// UpdateSubmissionStatus updates the workflow status of a submission.
// @Summary Update tender submission status
// @Description Move a tender submission to the next workflow step
// @Tags TenderSubmissions
// @Accept json
// @Produce json
// @Param id path string true "Submission ID"
// @Param body body UpdateSubmissionStatusForm true "Status update"
// @Success 200 {object} response.APIResponse{data=TenderSubmissionWithTenderResponse}
// @Failure 400 {object} response.APIResponse
// @Failure 404 {object} response.APIResponse
// @Failure 422 {object} response.APIResponse
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /api/v1/tender-submissions/{id}/status [patch]
func (h *Handler) UpdateSubmissionStatus(c echo.Context) error {
	id := strings.TrimSpace(c.Param("id"))
	if id == "" {
		return response.BadRequest(c, "Submission ID is required", "")
	}

	form, err := response.Parse[UpdateSubmissionStatusForm](c)
	if err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	companyID, err := h.resolveCompanyID(c)
	if err != nil {
		if errors.Is(err, customer.ErrCompanyNotAssigned) {
			return response.Forbidden(c, "Company is not assigned to customer")
		}
		return response.BadRequest(c, "Company ID is required", "")
	}

	customerID, _ := customer.GetCustomerIDFromContext(c)
	result, err := h.service.UpdateStatus(c.Request().Context(), id, form, companyID, customerID)
	if err != nil {
		if errors.Is(err, ErrTenderSubmissionNotFound) {
			return response.NotFound(c, "Tender submission not found")
		}
		var transitionErr *InvalidStatusTransitionError
		if errors.As(err, &transitionErr) {
			return response.ValidationError(c, "Invalid status transition", err.Error())
		}
		if errors.Is(err, ErrTerminalStatus) {
			return response.ValidationError(c, "Submission is in a terminal state", err.Error())
		}
		if errors.Is(err, ErrConcurrentUpdate) {
			return response.Conflict(c, "Tender submission was modified concurrently")
		}
		return response.InternalServerError(c, "Failed to update tender submission status")
	}

	return response.Success(c, result, "Tender submission status updated successfully")
}

// GetCompanySubmissionStats returns submission statistics for the company.
// @Summary Get company tender submission statistics
// @Description Retrieve submission counts grouped by stage and status
// @Tags TenderSubmissions
// @Accept json
// @Produce json
// @Success 200 {object} response.APIResponse{data=CompanySubmissionStatsResponse}
// @Failure 401 {object} response.APIResponse
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /api/v1/tender-submissions/stats [get]
func (h *Handler) GetCompanySubmissionStats(c echo.Context) error {
	companyID, ok := c.Get("company_id").(string)
	if !ok || companyID == "" {
		return response.Unauthorized(c, "Unauthorized")
	}

	stats, err := h.service.GetCompanyStats(c.Request().Context(), companyID)
	if err != nil {
		return response.InternalServerError(c, "Failed to get submission statistics")
	}

	return response.Success(c, stats, "Submission statistics retrieved successfully")
}

// AdminListSubmissions lists tender submissions for admin users.
// @Summary Admin list tender submissions
// @Description Retrieve paginated tender submissions across companies
// @Tags Admin-TenderSubmissions
// @Accept json
// @Produce json
// @Param company_id query string false "Filter by company ID"
// @Param tender_id query string false "Filter by tender ID"
// @Param status query []string false "Filter by status"
// @Param stage query []string false "Filter by stage"
// @Param limit query int false "Page size"
// @Param offset query int false "Pagination offset"
// @Success 200 {object} response.APIResponse{data=TenderSubmissionListResponse}
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /admin/v1/tender-submissions [get]
func (h *Handler) AdminListSubmissions(c echo.Context) error {
	form, err := response.Parse[ListTenderSubmissionsForm](c)
	if err != nil {
		return response.ValidationError(c, "Invalid request data", err.Error())
	}

	result, err := h.service.AdminListWithTender(c.Request().Context(), form)
	if err != nil {
		return response.InternalServerError(c, "Failed to list tender submissions")
	}

	return response.SuccessWithMeta(c, result.Submissions, result.Metadata, "Tender submissions retrieved successfully")
}

// AdminGetSubmissionByID retrieves a submission by ID for admin users.
// @Summary Admin get tender submission by ID
// @Description Retrieve a tender submission workflow with tender details
// @Tags Admin-TenderSubmissions
// @Accept json
// @Produce json
// @Param id path string true "Submission ID"
// @Success 200 {object} response.APIResponse{data=TenderSubmissionWithTenderResponse}
// @Failure 404 {object} response.APIResponse
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /admin/v1/tender-submissions/{id} [get]
func (h *Handler) AdminGetSubmissionByID(c echo.Context) error {
	id := strings.TrimSpace(c.Param("id"))
	if id == "" {
		return response.BadRequest(c, "Submission ID is required", "")
	}

	result, err := h.service.GetByIDWithTender(c.Request().Context(), id)
	if err != nil {
		if errors.Is(err, ErrTenderSubmissionNotFound) {
			return response.NotFound(c, "Tender submission not found")
		}
		return response.InternalServerError(c, "Failed to get tender submission")
	}

	return response.Success(c, result, "Tender submission retrieved successfully")
}

// AdminGetSubmissionStats returns global submission statistics.
// @Summary Admin get tender submission statistics
// @Description Retrieve global submission counts grouped by stage and status
// @Tags Admin-TenderSubmissions
// @Accept json
// @Produce json
// @Success 200 {object} response.APIResponse{data=AdminSubmissionStatsResponse}
// @Failure 500 {object} response.APIResponse
// @Security BearerAuth
// @Router /admin/v1/tender-submissions/stats [get]
func (h *Handler) AdminGetSubmissionStats(c echo.Context) error {
	stats, err := h.service.GetGlobalStats(c.Request().Context())
	if err != nil {
		return response.InternalServerError(c, "Failed to get submission statistics")
	}
	return response.Success(c, stats, "Submission statistics retrieved successfully")
}

func (h *Handler) resolveCompanyID(c echo.Context) (string, error) {
	requestedCompanyID := strings.TrimSpace(c.QueryParam("company_id"))
	activeCompanyID, _ := c.Get("company_id").(string)
	assignedCompanyIDs, _ := c.Get("company_ids").([]string)

	return customer.PickAssignedCompanyID(activeCompanyID, assignedCompanyIDs, requestedCompanyID)
}