// Per-tenant configuration for an EXTERNAL, already-running Ollama server
// (never installed on the archivdms host — the base URL/port comes from the
// tenant admin). Gates the optional 'ollama' metadata-suggestion provider.
//
//	GET /api/ollama-config
//	PUT /api/ollama-config
//
// Both are admin-only (domain_admin manages its own tenant; superadmin must
// pass ?tenant_id=), mirroring the LDAP-config and tenant-settings handlers.
// The base URL is an internal network URL, not a secret, and is returned as-is.
package api

import (
	"encoding/json"
	"net/http"
	"time"

	"archivdms/internal/audit"
	"archivdms/internal/llm"
)

// handleGetOllamaConfig returns the tenant's Ollama connection config. A tenant
// that has never configured Ollama gets a zero/default (disabled) config, not a
// 404 — the frontend always renders an editable form.
func (s *Server) handleGetOllamaConfig(w http.ResponseWriter, r *http.Request) {
	tenantID, ok := s.resolveTenantSettingsTenant(w, r)
	if !ok {
		return
	}
	cfg, err := s.store.GetOllamaConfig(r.Context(), tenantID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "load ollama config failed")
		return
	}
	writeJSON(w, http.StatusOK, cfg)
}

// handleListOllamaModels queries an Ollama server for the models actually
// installed there, so the frontend can offer a picklist instead of a free-text
// field. Live call, no caching. Prefers the not-yet-saved ?base_url= query
// param (lets the admin test a URL before hitting "Speichern"); falls back to
// the persisted config's base_url when the param is absent. 400 if neither is
// set. When the external Ollama server is unreachable the failure is the
// external dependency's, not ours → 502 Bad Gateway, not 500.
func (s *Server) handleListOllamaModels(w http.ResponseWriter, r *http.Request) {
	tenantID, ok := s.resolveTenantSettingsTenant(w, r)
	if !ok {
		return
	}

	cfg, err := s.store.GetOllamaConfig(r.Context(), tenantID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "load ollama config failed")
		return
	}
	baseURL := r.URL.Query().Get("base_url")
	if baseURL == "" {
		baseURL = cfg.BaseURL
	}
	if baseURL == "" {
		writeError(w, http.StatusBadRequest, "Server-URL muss zuerst eingetragen werden")
		return
	}

	// Short, listing-specific timeout — independent of the (possibly long)
	// generate timeout. Cap the stored value so a large generate timeout does
	// not make the picklist request hang for minutes.
	timeout := 10 * time.Second
	if cfg.TimeoutSeconds > 0 && cfg.TimeoutSeconds < 10 {
		timeout = time.Duration(cfg.TimeoutSeconds) * time.Second
	}

	models, err := llm.ListModels(r.Context(), baseURL, timeout)
	if err != nil {
		writeError(w, http.StatusBadGateway, "ollama nicht erreichbar: "+err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string][]string{"models": models})
}

type upsertOllamaConfigRequest struct {
	Enabled        bool   `json:"enabled"`
	BaseURL        string `json:"base_url"`
	Model          string `json:"model"`
	TimeoutSeconds int    `json:"timeout_seconds"`
}

// handleUpsertOllamaConfig creates or updates the tenant's Ollama connection
// config. Validation (enabled requires base_url+model, http(s) prefix, timeout
// range) lives in the store. Every attempt — success or failure — is
// audit-logged (GoBD).
func (s *Server) handleUpsertOllamaConfig(w http.ResponseWriter, r *http.Request) {
	sess := sessionFromCtx(r.Context())

	tenantID, ok := s.resolveTenantSettingsTenant(w, r)
	if !ok {
		return
	}

	logFail := func(detail string) {
		tid := tenantID
		s.audlog.Log(audit.Entry{
			EventType: audit.EventOllamaConfigUpdate, Username: sess.Username,
			TenantID: &tid, Success: false, Detail: detail,
		})
	}

	var req upsertOllamaConfigRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		logFail("ollama_config invalid_body")
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}

	if err := s.store.UpsertOllamaConfig(r.Context(), tenantID, req.Enabled, req.BaseURL, req.Model, req.TimeoutSeconds); err != nil {
		logFail("ollama_config upsert_failed:" + err.Error())
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	tid := tenantID
	s.audlog.Log(audit.Entry{
		EventType: audit.EventOllamaConfigUpdate, Username: sess.Username,
		TenantID: &tid, Success: true, Detail: "ollama_config_saved",
	})

	// Reload so the response reflects the persisted (normalised) state.
	cfg, err := s.store.GetOllamaConfig(r.Context(), tenantID)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "load ollama config failed")
		return
	}
	writeJSON(w, http.StatusOK, cfg)
}