// Package note 提供便签接口。
package note

import (
	"net/http"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"rill/internal/httpx"
	"rill/internal/model"
)

// Request 创建/更新便签请求。
type Request struct {
	Title   string `json:"title" binding:"required,max=200" example:"Shopping list"`
	Content string `json:"content" example:"Milk, eggs"`
}

// ListResponse 便签分页列表响应。
type ListResponse struct {
	Items    []model.Note `json:"items"`
	Total    int64        `json:"total" example:"42"`
	Page     int          `json:"page" example:"1"`
	PageSize int          `json:"page_size" example:"20"`
}

// @Summary      List notes
// @Description  List notes ordered by id DESC. page starts at 1; page_size is 1-100, default 20.
// @Tags         user
// @Produce      json
// @Param        page       query     int  false  "Page number, default 1"                example(1)
// @Param        page_size  query     int  false  "Page size, default 20, max 100"  example(20)
// @Success      200        {object}  note.ListResponse
// @Failure      500        {object}  httpx.ErrorResponse
// @Security     BearerAuth
// @Failure      401  {object}  httpx.ErrorResponse  "unauthorized or session expired"
// @Failure      403  {object}  httpx.ErrorResponse  "account disabled"
// @Router       /notes [get]
func List(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		page, pageSize := httpx.ParsePagination(c)

		ctx := c.Request.Context()
		var total int64
		if err := db.WithContext(ctx).Model(&model.Note{}).Count(&total).Error; err != nil {
			httpx.RespondDBError(c, err)
			return
		}

		var notes []model.Note
		if err := db.WithContext(ctx).
			Order("id DESC").
			Offset((page - 1) * pageSize).
			Limit(pageSize).
			Find(&notes).Error; err != nil {
			httpx.RespondDBError(c, err)
			return
		}

		c.JSON(http.StatusOK, ListResponse{
			Items:    notes,
			Total:    total,
			Page:     page,
			PageSize: pageSize,
		})
	}
}

// @Summary      Create a note
// @Description  Create a note. title is required (max 200 chars); content is optional.
// @Tags         user
// @Accept       json
// @Produce      json
// @Param        note  body      note.Request  true  "Note payload"
// @Success      201   {object}  model.Note
// @Failure      400   {object}  httpx.ErrorResponse  "invalid request"
// @Failure      500   {object}  httpx.ErrorResponse
// @Security     BearerAuth
// @Failure      401  {object}  httpx.ErrorResponse  "unauthorized or session expired"
// @Failure      403  {object}  httpx.ErrorResponse  "account disabled"
// @Router       /notes [post]
func Create(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		var req Request
		if err := c.ShouldBindJSON(&req); err != nil {
			c.JSON(http.StatusBadRequest, httpx.ErrorResponse{Error: "invalid request: " + err.Error()})
			return
		}

		note := model.Note{Title: req.Title, Content: req.Content}
		if err := db.WithContext(c.Request.Context()).Create(&note).Error; err != nil {
			httpx.RespondDBError(c, err)
			return
		}
		c.JSON(http.StatusCreated, note)
	}
}

// @Summary      Get a note
// @Description  Get a note by id.
// @Tags         user
// @Produce      json
// @Param        id   path      int  true  "Note ID"  example(1)
// @Success      200  {object}  model.Note
// @Failure      400  {object}  httpx.ErrorResponse  "invalid id"
// @Failure      404  {object}  httpx.ErrorResponse  "record not found"
// @Failure      500  {object}  httpx.ErrorResponse
// @Security     BearerAuth
// @Failure      401  {object}  httpx.ErrorResponse  "unauthorized or session expired"
// @Failure      403  {object}  httpx.ErrorResponse  "account disabled"
// @Router       /notes/{id} [get]
func Get(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, ok := httpx.ParseID(c)
		if !ok {
			return
		}

		var note model.Note
		if err := db.WithContext(c.Request.Context()).First(&note, id).Error; err != nil {
			httpx.RespondGetError(c, err)
			return
		}
		c.JSON(http.StatusOK, note)
	}
}

// @Summary      Update a note
// @Description  Update title and content; validation is the same as create.
// @Tags         user
// @Accept       json
// @Produce      json
// @Param        id    path      int           true  "Note ID"  example(1)
// @Param        note  body      note.Request  true  "Note payload"
// @Success      200   {object}  model.Note
// @Failure      400   {object}  httpx.ErrorResponse  "invalid request or id"
// @Failure      404   {object}  httpx.ErrorResponse  "record not found"
// @Failure      500   {object}  httpx.ErrorResponse
// @Security     BearerAuth
// @Failure      401  {object}  httpx.ErrorResponse  "unauthorized or session expired"
// @Failure      403  {object}  httpx.ErrorResponse  "account disabled"
// @Router       /notes/{id} [put]
func Update(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, ok := httpx.ParseID(c)
		if !ok {
			return
		}

		var req Request
		if err := c.ShouldBindJSON(&req); err != nil {
			c.JSON(http.StatusBadRequest, httpx.ErrorResponse{Error: "invalid request: " + err.Error()})
			return
		}

		ctx := c.Request.Context()
		var note model.Note
		if err := db.WithContext(ctx).First(&note, id).Error; err != nil {
			httpx.RespondGetError(c, err)
			return
		}

		note.Title = req.Title
		note.Content = req.Content
		if err := db.WithContext(ctx).Save(&note).Error; err != nil {
			httpx.RespondDBError(c, err)
			return
		}
		c.JSON(http.StatusOK, note)
	}
}

// @Summary      Delete a note
// @Description  Delete a note by id; returns 204 with no body on success.
// @Tags         user
// @Produce      json
// @Param        id   path  int  true  "Note ID"  example(1)
// @Success      204  "Deleted"
// @Failure      400  {object}  httpx.ErrorResponse  "invalid id"
// @Failure      404  {object}  httpx.ErrorResponse  "record not found"
// @Failure      500  {object}  httpx.ErrorResponse
// @Security     BearerAuth
// @Failure      401  {object}  httpx.ErrorResponse  "unauthorized or session expired"
// @Failure      403  {object}  httpx.ErrorResponse  "account disabled"
// @Router       /notes/{id} [delete]
func Delete(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		id, ok := httpx.ParseID(c)
		if !ok {
			return
		}

		result := db.WithContext(c.Request.Context()).Delete(&model.Note{}, id)
		if result.Error != nil {
			httpx.RespondDBError(c, result.Error)
			return
		}
		if result.RowsAffected == 0 {
			c.JSON(http.StatusNotFound, httpx.ErrorResponse{Error: "record not found"})
			return
		}
		c.Status(http.StatusNoContent)
	}
}