package httpapi

import (
	"database/sql"
	"strconv"
	"strings"

	hres "form-builder-be-go/internal/hal"
	sq "form-builder-be-go/internal/sqlc"

	"github.com/gin-gonic/gin"
	"github.com/raff/halgo"
)

func RegisterActorRoutes(r *gin.Engine, db *sql.DB) {
	// List actors
	r.GET("/actors", func(c *gin.Context) {
		limit := parseIntDefault(c.Query("limit"), 20)
		if limit > 100 {
			limit = 100
		}
		offset := parseIntDefault(c.Query("offset"), 0)
		order := c.Query("order")
		expand := parseExpand(c.Query("expand"))

		q := sq.New(db)
		actors, err := q.ListActors(c, sq.ListActorsParams{Limit: int64(limit), Offset: int64(offset)})
		if err != nil {
			c.JSON(500, gin.H{"error": err.Error()})
			return
		}
		total, err := q.CountActors(c)
		if err != nil {
			c.JSON(500, gin.H{"error": err.Error()})
			return
		}

		selfURL := buildURL("/actors", limit, offset, order, c.Query("expand"))
		res := hres.New(selfURL)
		res.AddCurie()
		res.AddLink("self", halgo.Link{Href: selfURL})
		if int64(offset+limit) < total {
			nextURL := buildURL("/actors", limit, offset+limit, order, c.Query("expand"))
			res.AddLink("next", halgo.Link{Href: nextURL})
		}
		if offset > 0 {
			prev := offset - limit
			if prev < 0 {
				prev = 0
			}
			prevURL := buildURL("/actors", limit, prev, order, c.Query("expand"))
			res.AddLink("prev", halgo.Link{Href: prevURL})
		}

		var embedded []interface{}
		for _, a := range actors {
			itemURL := "/actors/" + strconv.FormatInt(int64(a.ActorID), 10)
			relFilmsURL := itemURL + "/films"
			item := hres.New(itemURL)
			item.SetState(a)
			item.AddLink("self", halgo.Link{Href: itemURL})
			item.AddLink("sakila:films", halgo.Link{Href: relFilmsURL})
			if expand["films"] {
				films, err := q.ListFilmsByActor(c, int64(a.ActorID))
				if err != nil {
					c.JSON(500, gin.H{"error": err.Error()})
					return
				}
				var filmEmbeds []interface{}
				for _, f := range films {
					filmURL := "/films/" + strconv.FormatInt(f.FilmID, 10)
					film := hres.New(filmURL)
					film.SetState(f)
					film.AddLink("self", halgo.Link{Href: filmURL})
					film.AddLink("sakila:actors", halgo.Link{Href: filmURL + "/actors"})
					filmEmbeds = append(filmEmbeds, film)
				}
				item.Embed("films", filmEmbeds)
			}
			embedded = append(embedded, item)
		}
		res.Embed("actors", embedded)
		res.SetState(gin.H{"count": len(actors), "total": total, "limit": limit, "offset": offset})
		c.Header("Content-Type", "application/hal+json")
		c.JSON(200, res)
	})

	// Get actor
	r.GET("/actors/:id", func(c *gin.Context) {
		id, err := strconv.ParseInt(c.Param("id"), 10, 64)
		if err != nil {
			c.JSON(400, gin.H{"error": "invalid id"})
			return
		}
		expand := parseExpand(c.Query("expand"))
		q := sq.New(db)
		aRec, err := q.GetActor(c, id)
		if err != nil {
			c.JSON(500, gin.H{"error": err.Error()})
			return
		}
		// sqlc returns error for not found
		self := "/actors/" + strconv.FormatInt(int64(aRec.ActorID), 10)
		relFilms := self + "/films"
		res := hres.New(self)
		res.AddCurie()
		res.SetState(aRec)
		res.AddLink("self", halgo.Link{Href: self})
		res.AddLink("sakila:films", halgo.Link{Href: relFilms})
		if expand["films"] {
			films, err := q.ListFilmsByActor(c, int64(aRec.ActorID))
			if err != nil {
				c.JSON(500, gin.H{"error": err.Error()})
				return
			}
			var filmEmbeds []interface{}
			for _, f := range films {
				filmURL := "/films/" + strconv.FormatInt(f.FilmID, 10)
				film := hres.New(filmURL)
				film.SetState(f)
				film.AddLink("self", halgo.Link{Href: filmURL})
				film.AddLink("sakila:actors", halgo.Link{Href: filmURL + "/actors"})
				filmEmbeds = append(filmEmbeds, film)
			}
			res.Embed("films", filmEmbeds)
		}
		c.Header("Content-Type", "application/hal+json")
		c.JSON(200, res)
	})

	// Create actor
	r.POST("/actors", func(c *gin.Context) {
		var in struct {
			ActorID   *int64 `json:"actor_id"`
			FirstName string `json:"first_name"`
			LastName  string `json:"last_name"`
		}
		if err := c.ShouldBindJSON(&in); err != nil {
			c.JSON(400, gin.H{"error": err.Error()})
			return
		}
		if strings.TrimSpace(in.FirstName) == "" || strings.TrimSpace(in.LastName) == "" {
			c.JSON(400, gin.H{"error": "first_name and last_name are required"})
			return
		}
		q := sq.New(db)
		var id int64
		if in.ActorID != nil {
			id = *in.ActorID
		} else {
			var err error
			id, err = q.NextActorID(c)
			if err != nil {
				c.JSON(500, gin.H{"error": err.Error()})
				return
			}
		}
		if err := q.InsertActor(c, sq.InsertActorParams{ActorID: id, FirstName: in.FirstName, LastName: in.LastName}); err != nil {
			c.JSON(400, gin.H{"error": err.Error()})
			return
		}
		created, err := q.GetActor(c, id)
		if err != nil {
			c.JSON(500, gin.H{"error": err.Error()})
			return
		}
		self := "/actors/" + strconv.FormatInt(int64(created.ActorID), 10)
		res := hres.New(self)
		res.AddCurie()
		res.SetState(created)
		res.AddLink("self", halgo.Link{Href: self})
		res.AddLink("sakila:films", halgo.Link{Href: self + "/films"})
		c.Header("Content-Type", "application/hal+json")
		c.Header("Location", self)
		c.JSON(201, res)
	})

	// Replace actor
	r.PUT("/actors/:id", func(c *gin.Context) {
		id, err := strconv.ParseInt(c.Param("id"), 10, 64)
		if err != nil {
			c.JSON(400, gin.H{"error": "invalid id"})
			return
		}
		var in struct {
			FirstName string `json:"first_name"`
			LastName  string `json:"last_name"`
		}
		if err := c.ShouldBindJSON(&in); err != nil {
			c.JSON(400, gin.H{"error": err.Error()})
			return
		}
		if strings.TrimSpace(in.FirstName) == "" || strings.TrimSpace(in.LastName) == "" {
			c.JSON(400, gin.H{"error": "first_name and last_name are required"})
			return
		}
		q := sq.New(db)
		aff, err := q.UpdateActorPut(c, sq.UpdateActorPutParams{FirstName: in.FirstName, LastName: in.LastName, ActorID: id})
		if err != nil {
			c.JSON(400, gin.H{"error": err.Error()})
			return
		}
		if aff == 0 {
			c.JSON(404, gin.H{"error": "not found"})
			return
		}
		updated, err := q.GetActor(c, id)
		if err != nil {
			c.JSON(500, gin.H{"error": err.Error()})
			return
		}
		self := "/actors/" + strconv.FormatInt(int64(updated.ActorID), 10)
		res := hres.New(self)
		res.AddCurie()
		res.SetState(updated)
		res.AddLink("self", halgo.Link{Href: self})
		res.AddLink("sakila:films", halgo.Link{Href: self + "/films"})
		c.Header("Content-Type", "application/hal+json")
		c.JSON(200, res)
	})

	// Patch actor
	r.PATCH("/actors/:id", func(c *gin.Context) {
		id, err := strconv.ParseInt(c.Param("id"), 10, 64)
		if err != nil {
			c.JSON(400, gin.H{"error": "invalid id"})
			return
		}
		var in struct {
			FirstName *string `json:"first_name"`
			LastName  *string `json:"last_name"`
		}
		if err := c.ShouldBindJSON(&in); err != nil {
			c.JSON(400, gin.H{"error": err.Error()})
			return
		}
		q := sq.New(db)
		toNullString := func(p *string) sql.NullString {
			if p == nil {
				return sql.NullString{Valid: false}
			}
			return sql.NullString{String: *p, Valid: true}
		}
		aff, err := q.PatchActor(c, sq.PatchActorParams{FirstName: toNullString(in.FirstName), LastName: toNullString(in.LastName), ActorID: id})
		if err != nil {
			c.JSON(400, gin.H{"error": err.Error()})
			return
		}
		if aff == 0 {
			c.JSON(404, gin.H{"error": "not found"})
			return
		}
		updated, err := q.GetActor(c, id)
		if err != nil {
			c.JSON(500, gin.H{"error": err.Error()})
			return
		}
		self := "/actors/" + strconv.FormatInt(int64(updated.ActorID), 10)
		res := hres.New(self)
		res.AddCurie()
		res.SetState(updated)
		res.AddLink("self", halgo.Link{Href: self})
		res.AddLink("sakila:films", halgo.Link{Href: self + "/films"})
		c.Header("Content-Type", "application/hal+json")
		c.JSON(200, res)
	})

	// Delete actor
	r.DELETE("/actors/:id", func(c *gin.Context) {
		id, err := strconv.ParseInt(c.Param("id"), 10, 64)
		if err != nil {
			c.JSON(400, gin.H{"error": "invalid id"})
			return
		}
		q := sq.New(db)
		aff, err := q.DeleteActor(c, id)
		if err != nil {
			c.JSON(400, gin.H{"error": err.Error()})
			return
		}
		if aff == 0 {
			c.JSON(404, gin.H{"error": "not found"})
			return
		}
		c.Status(204)
	})
}