package api

import (
	"github.com/gin-gonic/gin"
	"github.com/gissleh/stufflog/database"
	"github.com/gissleh/stufflog/internal/auth"
	"github.com/gissleh/stufflog/internal/generate"
	"github.com/gissleh/stufflog/internal/slerrors"
	"github.com/gissleh/stufflog/models"
	"github.com/gissleh/stufflog/services"
	"sort"
	"strings"
	"time"
)

func Task(g *gin.RouterGroup, db database.Database) {
	l := services.Loader{DB: db}

	g.GET("/", handler("tasks", func(c *gin.Context) (interface{}, error) {
		filter := models.TaskFilter{}
		if setting := c.Query("active"); setting != "" {
			active := setting == "true"
			filter.Active = &active
		}
		if setting := c.Query("expiring"); setting != "" {
			expiring := setting == "true"
			filter.Expiring = &expiring
		}

		tasks, err := l.ListTasks(c, filter)
		if err != nil {
			return nil, err
		}

		sort.Sort(
			models.TaskSorter{
				Fields: strings.Split(c.Query("sort"), ","),
				Data:   tasks,
			},
		)

		return tasks, nil
	}))

	g.GET("/:id", handler("task", func(c *gin.Context) (interface{}, error) {
		return l.FindTask(c, c.Param("id"))
	}))

	g.POST("/", handler("task", func(c *gin.Context) (interface{}, error) {
		createdTime := time.Now()
		task := models.Task{}
		err := c.BindJSON(&task)
		if err != nil {
			return nil, slerrors.BadRequest("Invalid JSON")
		}
		if task.EndTime != nil && task.EndTime.Before(createdTime) {
			return nil, slerrors.BadRequest("Task end time must be later than current time.")
		}
		if task.ItemAmount <= 0 {
			return nil, slerrors.BadRequest("Item amount cannot be zero or negative.")
		}

		project, err := l.FindProject(c.Request.Context(), task.ProjectID)
		if err != nil {
			return nil, err
		}
		item, err := l.FindItem(c.Request.Context(), task.ItemID)
		if err != nil {
			return nil, err
		}

		task.ID = generate.TaskID()
		task.UserID = auth.UserID(c)
		task.CreatedTime = time.Now().UTC()
		task.ItemID = item.ID
		task.ProjectID = project.ID

		err = db.Tasks().Insert(c.Request.Context(), task)
		if err != nil {
			return nil, err
		}

		return &models.TaskResult{
			Task:            task,
			Logs:            []*models.LogWithSecondaryItem{},
			Item:            &item.Item,
			CompletedAmount: 0,
		}, nil
	}))

	g.PUT("/:id", handler("task", func(c *gin.Context) (interface{}, error) {
		update := models.TaskUpdate{}
		err := c.BindJSON(&update)
		if err != nil {
			return nil, slerrors.BadRequest("Invalid JSON")
		}

		task, err := l.FindTask(c.Request.Context(), c.Param("id"))
		if err != nil {
			return nil, err
		}

		if update.ProjectID != nil && *update.ProjectID != task.ProjectID {
			project, err := l.FindProject(c.Request.Context(), *update.ProjectID)
			if err != nil {
				return nil, slerrors.NotFound("Destination project")
			}

			// Delete any links that would have been ran over.
			err = db.Tasks().DeleteLink(c.Request.Context(), models.TaskLink{
				TaskID:    task.ID,
				ProjectID: project.ID,
			})
			if err != nil {
				return nil, slerrors.BadRequest(err.Error())
			}

			task.ProjectID = project.ID
		}

		task.Update(update)
		if task.EndTime != nil && task.EndTime.Before(task.CreatedTime) {
			return nil, slerrors.BadRequest("Task end time must be later than it was created.")
		}
		if task.ItemAmount <= 0 {
			return nil, slerrors.BadRequest("Item amount cannot be zero or negative.")
		}

		err = db.Tasks().Update(c.Request.Context(), task.Task)
		if err != nil {
			return nil, err
		}

		return task, nil
	}))

	g.PUT("/:id/link/:project_id", handler("taskLink", func(c *gin.Context) (interface{}, error) {
		task, err := l.FindTask(c.Request.Context(), c.Param("id"))
		if err != nil {
			return nil, err
		}

		project, err := l.FindProject(c.Request.Context(), c.Param("project_id"))
		if err != nil {
			return nil, err
		}

		if task.ProjectID == project.ID {
			return nil, slerrors.BadRequest("You cannot link a task within its own project")
		}

		err = db.Tasks().CreateLink(c.Request.Context(), models.TaskLink{
			TaskID:    task.ID,
			ProjectID: project.ID,
		})

		return &models.TaskLink{
			TaskID:    task.ID,
			ProjectID: project.ID,
		}, nil
	}))

	g.DELETE("/:id/link/:project_id", handler("taskLink", func(c *gin.Context) (interface{}, error) {
		task, err := l.FindTask(c.Request.Context(), c.Param("id"))
		if err != nil {
			return nil, err
		}

		project, err := l.FindProject(c.Request.Context(), c.Param("project_id"))
		if err != nil {
			return nil, err
		}

		err = db.Tasks().DeleteLink(c.Request.Context(), models.TaskLink{
			TaskID:    task.ID,
			ProjectID: project.ID,
		})
		if err != nil {
			return nil, err
		}

		return &models.TaskLink{
			TaskID:    task.ID,
			ProjectID: project.ID,
		}, nil
	}))

	g.DELETE("/:id", handler("task", func(c *gin.Context) (interface{}, error) {
		task, err := l.FindTask(c.Request.Context(), c.Param("id"))
		if err != nil {
			return nil, err
		}

		if len(task.Logs) > 0 {
			return nil, slerrors.Forbidden("cannot delete tasks with logs.")
		}

		err = db.Tasks().Delete(c.Request.Context(), task.Task)
		if err != nil {
			return nil, err
		}

		return task, nil
	}))
}