package server

import (
	"errors"
	"net/http"

	"github.com/crypto/byteclaw/internal/providers"
	"github.com/crypto/byteclaw/internal/store"
)

func (s *Server) info(w http.ResponseWriter, _ *http.Request) {
	in := s.Info
	if s.Providers != nil {
		a := s.Providers.Active()
		in.Provider, in.Model, in.BaseURL = a.Provider, a.Model, s.Providers.BaseURL(a.Provider)
	}
	writeJSON(w, 200, in)
}

func (s *Server) needProviders(w http.ResponseWriter) bool {
	if s.Providers == nil {
		writeErr(w, http.StatusNotImplemented, "provider switching not enabled")
		return false
	}
	return true
}

func providerErr(w http.ResponseWriter, err error) {
	switch {
	case errors.Is(err, providers.ErrUnknown):
		writeErr(w, http.StatusNotFound, err.Error())
	default:
		writeErr(w, http.StatusBadRequest, err.Error())
	}
}

type providerReq struct {
	Provider string `json:"provider"`
	Model    string `json:"model"`
}

// GET /api/providers -> {"active":{...},"providers":[...]} (never contains keys).
func (s *Server) listProviders(w http.ResponseWriter, _ *http.Request) {
	if !s.needProviders(w) {
		return
	}
	writeJSON(w, 200, map[string]any{"active": s.Providers.Active(), "providers": s.Providers.List()})
}

func (s *Server) setActiveProvider(w http.ResponseWriter, r *http.Request) {
	if !s.needProviders(w) {
		return
	}
	var b providerReq
	if !decode(w, r, &b) {
		return
	}
	a, err := s.Providers.SetActive(r.Context(), b.Provider, b.Model)
	if err != nil {
		providerErr(w, err)
		return
	}
	writeJSON(w, 200, a)
}

func (s *Server) listModels(w http.ResponseWriter, r *http.Request) {
	if !s.needProviders(w) {
		return
	}
	ids, err := s.Providers.Models(r.Context(), r.PathValue("name"))
	if errors.Is(err, providers.ErrUnknown) {
		providerErr(w, err)
		return
	}
	if err != nil {
		s.Log.Warn("list models", "err", err)
		writeErr(w, http.StatusBadGateway, "provider does not offer a model list")
		return
	}
	writeJSON(w, 200, map[string]any{"models": ids})
}

// PUT /api/sessions/{id}/provider: per-session override; empty provider clears it.
func (s *Server) setSessionProvider(w http.ResponseWriter, r *http.Request) {
	if !s.needProviders(w) {
		return
	}
	var b providerReq
	if !decode(w, r, &b) {
		return
	}
	id := r.PathValue("id")
	if !s.owns(w, r, id) {
		return
	}
	var a providers.Active
	if b.Provider != "" {
		var err error
		if a, err = s.Providers.Validate(b.Provider, b.Model); err != nil {
			providerErr(w, err)
			return
		}
	}
	if err := s.Store.SetSessionProvider(r.Context(), id, a.Provider, a.Model); err != nil {
		s.storeErr(w, err)
		return
	}
	writeJSON(w, 200, a)
}

func (s *Server) cancel(w http.ResponseWriter, r *http.Request) {
	if !s.owns(w, r, r.PathValue("id")) {
		return
	}
	writeJSON(w, 200, map[string]bool{"cancelled": s.Agent.Cancel(r.PathValue("id"))})
}

func (s *Server) summarize(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	if !s.owns(w, r, id) {
		return
	}
	sm, err := s.Agent.SummarizeNow(r.Context(), id)
	if err != nil {
		s.Log.Warn("summarize", "err", err)
		writeErr(w, http.StatusBadGateway, err.Error())
		return
	}
	if sm == nil {
		writeJSON(w, 200, map[string]any{"summary": nil, "note": "nothing to summarize yet"})
		return
	}
	writeJSON(w, 200, map[string]any{"summary": sm})
}

func (s *Server) getSummary(w http.ResponseWriter, r *http.Request) {
	if !s.owns(w, r, r.PathValue("id")) {
		return
	}
	sm, err := s.Store.LatestSummary(r.Context(), r.PathValue("id"))
	if err != nil {
		if errors.Is(err, store.ErrNotFound) {
			writeErr(w, http.StatusNotFound, "no summary")
			return
		}
		s.storeErr(w, err)
		return
	}
	writeJSON(w, 200, sm)
}