package httpapi

import (
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"

	"git.apinb.com/ops/license/internal/subject"
)

type subjectHandler struct {
	service *subject.Service
}

type subjectRequest struct {
	PlatformName string `json:"platform_name"`
	Workspace    string `json:"workspace"`
}

type subjectView struct {
	ID           uuid.UUID `json:"id"`
	PlatformName string    `json:"platform_name"`
	Workspace    string    `json:"workspace"`
	CreatedAt    string    `json:"created_at"`
	UpdatedAt    string    `json:"updated_at"`
	LicenceCount int64     `json:"licence_count"`
}

func (h subjectHandler) list(c *gin.Context) {
	page, pageSize, ok := parsePagination(c)
	if !ok {
		writeBadRequest(c)
		return
	}
	items, total, err := h.service.List(c.Request.Context(), c.Query("q"), page, pageSize)
	if err != nil {
		writeError(c, err)
		return
	}
	views := make([]subjectView, len(items))
	for index := range items {
		views[index] = newSubjectView(items[index])
	}
	writePage(c, views, page, pageSize, total)
}

func (h subjectHandler) create(c *gin.Context) {
	request, ok := readSubjectRequest(c)
	if !ok {
		return
	}
	item, err := h.service.Create(c.Request.Context(), subject.UpsertInput{
		PlatformName: request.PlatformName,
		Workspace:    request.Workspace,
	})
	if err != nil {
		writeError(c, err)
		return
	}
	writeData(c, http.StatusCreated, newSubjectView(item))
}

func (h subjectHandler) get(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	item, err := h.service.Get(c.Request.Context(), id)
	if err != nil {
		writeError(c, err)
		return
	}
	writeData(c, http.StatusOK, newSubjectView(item))
}

func (h subjectHandler) update(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	request, ok := readSubjectRequest(c)
	if !ok {
		return
	}
	item, err := h.service.Update(c.Request.Context(), id, subject.UpsertInput{
		PlatformName: request.PlatformName,
		Workspace:    request.Workspace,
	})
	if err != nil {
		writeError(c, err)
		return
	}
	writeData(c, http.StatusOK, newSubjectView(item))
}

func (h subjectHandler) delete(c *gin.Context) {
	id, ok := parseID(c)
	if !ok {
		return
	}
	if err := h.service.Delete(c.Request.Context(), id); err != nil {
		writeError(c, err)
		return
	}
	writeData(c, http.StatusOK, nil)
}

func readSubjectRequest(c *gin.Context) (subjectRequest, bool) {
	var request subjectRequest
	if err := decodeJSON(c, &request); err != nil {
		writeBadRequest(c)
		return subjectRequest{}, false
	}
	return request, true
}

func parsePagination(c *gin.Context) (int, int, bool) {
	page, pageSize := 1, 20
	if raw, exists := c.GetQuery("page"); exists {
		value, err := strconv.Atoi(raw)
		if err != nil || value < 1 {
			return 0, 0, false
		}
		page = value
	}
	if raw, exists := c.GetQuery("page_size"); exists {
		value, err := strconv.Atoi(raw)
		if err != nil || value < 1 || value > 100 {
			return 0, 0, false
		}
		pageSize = value
	}
	return page, pageSize, true
}

func parseID(c *gin.Context) (uuid.UUID, bool) {
	id, err := uuid.Parse(c.Param("id"))
	if err != nil || id == uuid.Nil {
		writeBadRequest(c)
		return uuid.Nil, false
	}
	return id, true
}

func newSubjectView(item subject.Subject) subjectView {
	return subjectView{
		ID:           item.ID,
		PlatformName: item.PlatformName,
		Workspace:    item.Workspace,
		CreatedAt:    item.CreatedAt.UTC().Format(timeLayout),
		UpdatedAt:    item.UpdatedAt.UTC().Format(timeLayout),
		LicenceCount: item.LicenceCount,
	}
}