// Package routes provides HTTP route handlers for the Felt API.
// Each handler group corresponds to a domain entity and registers its routes
// with a chi router group.
package routes

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"net/http"
	"strconv"

	"github.com/go-chi/chi/v5"

	"github.com/felt-app/felt/internal/blind"
	"github.com/felt-app/felt/internal/server/middleware"
	"github.com/felt-app/felt/internal/template"
)

// TemplateRoutes holds all building block route handlers and their services.
type TemplateRoutes struct {
	chipSets   *template.ChipSetService
	blinds     *blind.StructureService
	payouts    *template.PayoutService
	buyins     *template.BuyinService
	templates  *template.TournamentTemplateService
	wizard     *blind.WizardService
}

// NewTemplateRoutes creates a new TemplateRoutes with all services initialized.
func NewTemplateRoutes(db *sql.DB) *TemplateRoutes {
	return &TemplateRoutes{
		chipSets:   template.NewChipSetService(db),
		blinds:     blind.NewStructureService(db),
		payouts:    template.NewPayoutService(db),
		buyins:     template.NewBuyinService(db),
		templates:  template.NewTournamentTemplateService(db),
		wizard:     blind.NewWizardService(db),
	}
}

// Register mounts all template-related routes on the given chi router.
// All routes require auth. Create/update/delete require admin role.
func (tr *TemplateRoutes) Register(r chi.Router) {
	// Chip Sets
	r.Route("/chip-sets", func(r chi.Router) {
		r.Get("/", tr.listChipSets)
		r.Get("/{id}", tr.getChipSet)
		r.Group(func(r chi.Router) {
			r.Use(middleware.RequireRole(middleware.RoleAdmin))
			r.Post("/", tr.createChipSet)
			r.Put("/{id}", tr.updateChipSet)
			r.Delete("/{id}", tr.deleteChipSet)
			r.Post("/{id}/duplicate", tr.duplicateChipSet)
		})
	})

	// Blind Structures
	r.Route("/blind-structures", func(r chi.Router) {
		r.Get("/", tr.listBlindStructures)
		r.Get("/{id}", tr.getBlindStructure)
		r.Group(func(r chi.Router) {
			r.Use(middleware.RequireRole(middleware.RoleAdmin))
			r.Post("/", tr.createBlindStructure)
			r.Put("/{id}", tr.updateBlindStructure)
			r.Delete("/{id}", tr.deleteBlindStructure)
			r.Post("/{id}/duplicate", tr.duplicateBlindStructure)
			r.Post("/wizard", tr.wizardGenerate)
		})
	})

	// Payout Structures
	r.Route("/payout-structures", func(r chi.Router) {
		r.Get("/", tr.listPayoutStructures)
		r.Get("/{id}", tr.getPayoutStructure)
		r.Group(func(r chi.Router) {
			r.Use(middleware.RequireRole(middleware.RoleAdmin))
			r.Post("/", tr.createPayoutStructure)
			r.Put("/{id}", tr.updatePayoutStructure)
			r.Delete("/{id}", tr.deletePayoutStructure)
			r.Post("/{id}/duplicate", tr.duplicatePayoutStructure)
		})
	})

	// Buy-in Configs
	r.Route("/buyin-configs", func(r chi.Router) {
		r.Get("/", tr.listBuyinConfigs)
		r.Get("/{id}", tr.getBuyinConfig)
		r.Group(func(r chi.Router) {
			r.Use(middleware.RequireRole(middleware.RoleAdmin))
			r.Post("/", tr.createBuyinConfig)
			r.Put("/{id}", tr.updateBuyinConfig)
			r.Delete("/{id}", tr.deleteBuyinConfig)
			r.Post("/{id}/duplicate", tr.duplicateBuyinConfig)
		})
	})

	// Tournament Templates
	r.Route("/tournament-templates", func(r chi.Router) {
		r.Get("/", tr.listTournamentTemplates)
		r.Get("/{id}", tr.getTournamentTemplate)
		r.Get("/{id}/expanded", tr.getTournamentTemplateExpanded)
		r.Group(func(r chi.Router) {
			r.Use(middleware.RequireRole(middleware.RoleAdmin))
			r.Post("/", tr.createTournamentTemplate)
			r.Put("/{id}", tr.updateTournamentTemplate)
			r.Delete("/{id}", tr.deleteTournamentTemplate)
			r.Post("/{id}/duplicate", tr.duplicateTournamentTemplate)
		})
	})
}

// --- Helpers ---

// parseID extracts an integer ID from the URL path parameter.
func parseID(r *http.Request) (int64, error) {
	idStr := chi.URLParam(r, "id")
	id, err := strconv.ParseInt(idStr, 10, 64)
	if err != nil {
		return 0, fmt.Errorf("invalid id: %s", idStr)
	}
	return id, nil
}

// writeJSON writes a JSON response with the given status code.
func writeJSON(w http.ResponseWriter, status int, v interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(v)
}

// writeError writes an error JSON response.
func writeError(w http.ResponseWriter, status int, msg string) {
	writeJSON(w, status, map[string]string{"error": msg})
}

// --- Chip Set Handlers ---

func (tr *TemplateRoutes) listChipSets(w http.ResponseWriter, r *http.Request) {
	sets, err := tr.chipSets.ListChipSets(r.Context())
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, sets)
}

func (tr *TemplateRoutes) getChipSet(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	cs, err := tr.chipSets.GetChipSet(r.Context(), id)
	if err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, cs)
}

type createChipSetRequest struct {
	Name          string                       `json:"name"`
	Denominations []template.ChipDenomination  `json:"denominations"`
}

func (tr *TemplateRoutes) createChipSet(w http.ResponseWriter, r *http.Request) {
	var req createChipSetRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	cs, err := tr.chipSets.CreateChipSet(r.Context(), req.Name, req.Denominations)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, cs)
}

type updateChipSetRequest struct {
	Name          string                       `json:"name"`
	Denominations []template.ChipDenomination  `json:"denominations"`
}

func (tr *TemplateRoutes) updateChipSet(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var req updateChipSetRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	if err := tr.chipSets.UpdateChipSet(r.Context(), id, req.Name, req.Denominations); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "updated"})
}

func (tr *TemplateRoutes) deleteChipSet(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := tr.chipSets.DeleteChipSet(r.Context(), id); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
}

type duplicateRequest struct {
	Name string `json:"name"`
}

func (tr *TemplateRoutes) duplicateChipSet(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var req duplicateRequest
	json.NewDecoder(r.Body).Decode(&req) // name is optional
	cs, err := tr.chipSets.DuplicateChipSet(r.Context(), id, req.Name)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, cs)
}

// --- Blind Structure Handlers ---

func (tr *TemplateRoutes) listBlindStructures(w http.ResponseWriter, r *http.Request) {
	structs, err := tr.blinds.ListStructures(r.Context())
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, structs)
}

func (tr *TemplateRoutes) getBlindStructure(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	bs, err := tr.blinds.GetStructure(r.Context(), id)
	if err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, bs)
}

type createBlindStructureRequest struct {
	Name   string             `json:"name"`
	Levels []blind.BlindLevel `json:"levels"`
}

func (tr *TemplateRoutes) createBlindStructure(w http.ResponseWriter, r *http.Request) {
	var req createBlindStructureRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	bs, err := tr.blinds.CreateStructure(r.Context(), req.Name, req.Levels)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, bs)
}

type updateBlindStructureRequest struct {
	Name   string             `json:"name"`
	Levels []blind.BlindLevel `json:"levels"`
}

func (tr *TemplateRoutes) updateBlindStructure(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var req updateBlindStructureRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	if err := tr.blinds.UpdateStructure(r.Context(), id, req.Name, req.Levels); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "updated"})
}

func (tr *TemplateRoutes) deleteBlindStructure(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := tr.blinds.DeleteStructure(r.Context(), id); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
}

func (tr *TemplateRoutes) duplicateBlindStructure(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var req duplicateRequest
	json.NewDecoder(r.Body).Decode(&req)
	bs, err := tr.blinds.DuplicateStructure(r.Context(), id, req.Name)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, bs)
}

// --- Wizard Handler ---

type wizardRequest struct {
	PlayerCount           int   `json:"player_count"`
	StartingChips         int64 `json:"starting_chips"`
	TargetDurationMinutes int   `json:"target_duration_minutes"`
	ChipSetID             int64 `json:"chip_set_id"`
}

func (tr *TemplateRoutes) wizardGenerate(w http.ResponseWriter, r *http.Request) {
	var req wizardRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	levels, err := tr.wizard.Generate(r.Context(), blind.WizardInput{
		PlayerCount:           req.PlayerCount,
		StartingChips:         req.StartingChips,
		TargetDurationMinutes: req.TargetDurationMinutes,
		ChipSetID:             req.ChipSetID,
	})
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]interface{}{
		"levels": levels,
	})
}

// --- Payout Structure Handlers ---

func (tr *TemplateRoutes) listPayoutStructures(w http.ResponseWriter, r *http.Request) {
	structs, err := tr.payouts.ListPayoutStructures(r.Context())
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, structs)
}

func (tr *TemplateRoutes) getPayoutStructure(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	ps, err := tr.payouts.GetPayoutStructure(r.Context(), id)
	if err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, ps)
}

type createPayoutStructureRequest struct {
	Name     string                   `json:"name"`
	Brackets []template.PayoutBracket `json:"brackets"`
}

func (tr *TemplateRoutes) createPayoutStructure(w http.ResponseWriter, r *http.Request) {
	var req createPayoutStructureRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	ps, err := tr.payouts.CreatePayoutStructure(r.Context(), req.Name, req.Brackets)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, ps)
}

type updatePayoutStructureRequest struct {
	Name     string                   `json:"name"`
	Brackets []template.PayoutBracket `json:"brackets"`
}

func (tr *TemplateRoutes) updatePayoutStructure(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var req updatePayoutStructureRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	if err := tr.payouts.UpdatePayoutStructure(r.Context(), id, req.Name, req.Brackets); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "updated"})
}

func (tr *TemplateRoutes) deletePayoutStructure(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := tr.payouts.DeletePayoutStructure(r.Context(), id); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
}

func (tr *TemplateRoutes) duplicatePayoutStructure(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var req duplicateRequest
	json.NewDecoder(r.Body).Decode(&req)
	ps, err := tr.payouts.DuplicatePayoutStructure(r.Context(), id, req.Name)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, ps)
}

// --- Buy-in Config Handlers ---

func (tr *TemplateRoutes) listBuyinConfigs(w http.ResponseWriter, r *http.Request) {
	configs, err := tr.buyins.ListBuyinConfigs(r.Context())
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, configs)
}

func (tr *TemplateRoutes) getBuyinConfig(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	cfg, err := tr.buyins.GetBuyinConfig(r.Context(), id)
	if err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, cfg)
}

func (tr *TemplateRoutes) createBuyinConfig(w http.ResponseWriter, r *http.Request) {
	var cfg template.BuyinConfig
	if err := json.NewDecoder(r.Body).Decode(&cfg); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	result, err := tr.buyins.CreateBuyinConfig(r.Context(), &cfg)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, result)
}

func (tr *TemplateRoutes) updateBuyinConfig(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var cfg template.BuyinConfig
	if err := json.NewDecoder(r.Body).Decode(&cfg); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	if err := tr.buyins.UpdateBuyinConfig(r.Context(), id, &cfg); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "updated"})
}

func (tr *TemplateRoutes) deleteBuyinConfig(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := tr.buyins.DeleteBuyinConfig(r.Context(), id); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
}

func (tr *TemplateRoutes) duplicateBuyinConfig(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var req duplicateRequest
	json.NewDecoder(r.Body).Decode(&req)
	cfg, err := tr.buyins.DuplicateBuyinConfig(r.Context(), id, req.Name)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, cfg)
}

// --- Tournament Template Handlers ---

func (tr *TemplateRoutes) listTournamentTemplates(w http.ResponseWriter, r *http.Request) {
	templates, err := tr.templates.ListTemplates(r.Context())
	if err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, templates)
}

func (tr *TemplateRoutes) getTournamentTemplate(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	tmpl, err := tr.templates.GetTemplate(r.Context(), id)
	if err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, tmpl)
}

func (tr *TemplateRoutes) getTournamentTemplateExpanded(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	expanded, err := tr.templates.GetTemplateExpanded(r.Context(), id)
	if err != nil {
		writeError(w, http.StatusNotFound, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, expanded)
}

func (tr *TemplateRoutes) createTournamentTemplate(w http.ResponseWriter, r *http.Request) {
	var tmpl template.TournamentTemplate
	if err := json.NewDecoder(r.Body).Decode(&tmpl); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	result, err := tr.templates.CreateTemplate(r.Context(), &tmpl)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, result)
}

func (tr *TemplateRoutes) updateTournamentTemplate(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var tmpl template.TournamentTemplate
	if err := json.NewDecoder(r.Body).Decode(&tmpl); err != nil {
		writeError(w, http.StatusBadRequest, "invalid JSON: "+err.Error())
		return
	}
	tmpl.ID = id
	if err := tr.templates.UpdateTemplate(r.Context(), &tmpl); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "updated"})
}

func (tr *TemplateRoutes) deleteTournamentTemplate(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := tr.templates.DeleteTemplate(r.Context(), id); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"status": "deleted"})
}

func (tr *TemplateRoutes) duplicateTournamentTemplate(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	var req duplicateRequest
	json.NewDecoder(r.Body).Decode(&req)
	tmpl, err := tr.templates.DuplicateTemplate(r.Context(), id, req.Name)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusCreated, tmpl)
}