package handlers

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

	"git.nakama.town/fmartingr/hako/internal/archival/archiver"
	archivalRules "git.nakama.town/fmartingr/hako/internal/archival/rules"
	archivalStore "git.nakama.town/fmartingr/hako/internal/archival/store"
	"git.nakama.town/fmartingr/hako/internal/extractors"
	"git.nakama.town/fmartingr/hako/internal/model"
	"git.nakama.town/fmartingr/hako/internal/server/webcontext"
)

// SystemHandler handles system-related requests
type SystemHandler struct {
	getVersion          func(ctx context.Context) (string, error)
	extractorMgr        *extractors.Manager
	archiverMgr         *archiver.Manager
	archiverConfigStore *archivalStore.ArchiverConfigStore
	settingsStore       *archivalStore.SettingsStore
}

// NewSystemHandler creates a new SystemHandler
func NewSystemHandler(getVersion func(ctx context.Context) (string, error), extractorMgr *extractors.Manager, archiverMgr *archiver.Manager, archiverConfigStore *archivalStore.ArchiverConfigStore, settingsStore *archivalStore.SettingsStore) *SystemHandler {
	return &SystemHandler{
		getVersion:          getVersion,
		extractorMgr:        extractorMgr,
		archiverMgr:         archiverMgr,
		archiverConfigStore: archiverConfigStore,
		settingsStore:       settingsStore,
	}
}

// SystemResponse represents a system response
type SystemResponse struct {
	Version string `json:"version,omitempty"`
	Commit  string `json:"commit,omitempty"`
	Date    string `json:"date,omitempty"`
}

// HandleSystem handles GET /system
func (h *SystemHandler) HandleSystem(w http.ResponseWriter, r *http.Request) {
	// Create webcontext for this request
	c := webcontext.NewWebContext(w, r)

	c.ResponseWriter().Header().Set("Content-Type", "application/json")
	c.ResponseWriter().WriteHeader(http.StatusOK)

	response := SystemResponse{
		Version: model.BuildVersion,
		Commit:  model.BuildCommit,
		Date:    model.BuildDate,
	}
	_ = json.NewEncoder(c.ResponseWriter()).Encode(response)
}

// HandleExtractors handles GET /system/extractors
func (h *SystemHandler) HandleExtractors(w http.ResponseWriter, r *http.Request) {
	c := webcontext.NewWebContext(w, r)

	// Get status of all extractors
	statuses := h.extractorMgr.GetStatus()

	c.ResponseWriter().Header().Set("Content-Type", "application/json")
	c.ResponseWriter().WriteHeader(http.StatusOK)
	_ = json.NewEncoder(c.ResponseWriter()).Encode(statuses)
}

// HandleArchivers handles GET /system/archivers
func (h *SystemHandler) HandleArchivers(w http.ResponseWriter, r *http.Request) {
	c := webcontext.NewWebContext(w, r)

	// Get status of all archivers
	statuses := h.archiverMgr.GetStatus(c.Context(), h.archiverConfigStore)

	c.ResponseWriter().Header().Set("Content-Type", "application/json")
	c.ResponseWriter().WriteHeader(http.StatusOK)
	_ = json.NewEncoder(c.ResponseWriter()).Encode(statuses)
}

// HandleGetArchiverConfig handles GET /system/archivers/{key}/config
func (h *SystemHandler) HandleGetArchiverConfig(w http.ResponseWriter, r *http.Request) {
	c := webcontext.NewWebContext(w, r)

	// Extract archiver key from path
	key := r.PathValue("key")
	if key == "" {
		http.Error(w, "Archiver key is required", http.StatusBadRequest)
		return
	}

	// Get archiver to access default config
	arch, ok := h.archiverMgr.GetArchiver(key)
	if !ok {
		http.Error(w, fmt.Sprintf("Archiver not found: %s", key), http.StatusNotFound)
		return
	}

	// Try to get stored config
	storedConfig, err := h.archiverConfigStore.Get(c.Context(), key)
	if err != nil {
		http.Error(w, fmt.Sprintf("Failed to get archiver config: %v", err), http.StatusInternalServerError)
		return
	}

	var config any
	if storedConfig != nil && storedConfig.ConfigJSON != "" {
		// Parse stored config JSON
		if err := json.Unmarshal([]byte(storedConfig.ConfigJSON), &config); err != nil {
			// If parsing fails, fall back to default
			config = arch.GetDefaultConfig()
		}
	} else {
		// No stored config, use default
		config = arch.GetDefaultConfig()
	}

	c.ResponseWriter().Header().Set("Content-Type", "application/json")
	c.ResponseWriter().WriteHeader(http.StatusOK)
	_ = json.NewEncoder(c.ResponseWriter()).Encode(config)
}

// HandleSaveArchiverConfig handles PUT /system/archivers/{key}/config
func (h *SystemHandler) HandleSaveArchiverConfig(w http.ResponseWriter, r *http.Request) {
	c := webcontext.NewWebContext(w, r)

	// Extract archiver key from path
	key := r.PathValue("key")
	if key == "" {
		http.Error(w, "Archiver key is required", http.StatusBadRequest)
		return
	}

	// Verify archiver exists
	arch, ok := h.archiverMgr.GetArchiver(key)
	if !ok {
		http.Error(w, fmt.Sprintf("Archiver not found: %s", key), http.StatusNotFound)
		return
	}

	// Parse request body
	var config map[string]any
	if err := json.NewDecoder(r.Body).Decode(&config); err != nil {
		http.Error(w, fmt.Sprintf("Invalid JSON: %v", err), http.StatusBadRequest)
		return
	}

	// Validate config by trying to apply it
	if err := arch.ApplyConfig(config); err != nil {
		http.Error(w, fmt.Sprintf("Invalid config: %v", err), http.StatusBadRequest)
		return
	}

	// Marshal config back to JSON
	configJSON, err := json.Marshal(config)
	if err != nil {
		http.Error(w, fmt.Sprintf("Failed to marshal config: %v", err), http.StatusInternalServerError)
		return
	}

	// Save to database
	archiverConfig := &model.ArchiverConfig{
		ArchiverKey: key,
		ConfigJSON:  string(configJSON),
		UpdatedAt:   time.Now(),
	}

	if err := h.archiverConfigStore.Upsert(c.Context(), archiverConfig); err != nil {
		http.Error(w, fmt.Sprintf("Failed to save config: %v", err), http.StatusInternalServerError)
		return
	}

	c.ResponseWriter().Header().Set("Content-Type", "application/json")
	c.ResponseWriter().WriteHeader(http.StatusOK)
	_ = json.NewEncoder(c.ResponseWriter()).Encode(map[string]string{"message": "Config saved successfully"})
}

// HandleDeleteArchiverConfig handles DELETE /system/archivers/{key}/config
func (h *SystemHandler) HandleDeleteArchiverConfig(w http.ResponseWriter, r *http.Request) {
	c := webcontext.NewWebContext(w, r)

	// Extract archiver key from path
	key := r.PathValue("key")
	if key == "" {
		http.Error(w, "Archiver key is required", http.StatusBadRequest)
		return
	}

	// Verify archiver exists
	_, ok := h.archiverMgr.GetArchiver(key)
	if !ok {
		http.Error(w, fmt.Sprintf("Archiver not found: %s", key), http.StatusNotFound)
		return
	}

	// Delete from database
	if err := h.archiverConfigStore.Delete(c.Context(), key); err != nil {
		http.Error(w, fmt.Sprintf("Failed to delete config: %v", err), http.StatusInternalServerError)
		return
	}

	c.ResponseWriter().Header().Set("Content-Type", "application/json")
	c.ResponseWriter().WriteHeader(http.StatusOK)
	_ = json.NewEncoder(c.ResponseWriter()).Encode(map[string]string{"message": "Config reset to default successfully"})
}

// HandleGetRulesConfig handles GET /system/rules/config
func (h *SystemHandler) HandleGetRulesConfig(w http.ResponseWriter, r *http.Request) {
	c := webcontext.NewWebContext(w, r)

	// Get rules config from settings store
	rulesConfig, err := h.settingsStore.GetRulesConfig(c.Context())
	if err != nil {
		http.Error(w, fmt.Sprintf("Failed to get rules config: %v", err), http.StatusInternalServerError)
		return
	}

	// Convert to JSON format for frontend
	// We need to manually construct JSON since Rule is an interface
	rulesJSON := make([]json.RawMessage, len(rulesConfig.Rules))
	for i, rule := range rulesConfig.Rules {
		ruleBytes, err := json.Marshal(rule)
		if err != nil {
			http.Error(w, fmt.Sprintf("Failed to marshal rule %d: %v", i, err), http.StatusInternalServerError)
			return
		}
		rulesJSON[i] = ruleBytes
	}

	response := map[string]interface{}{
		"rules":              rulesJSON,
		"default_extractors": rulesConfig.DefaultArchivers, // JSON key kept for backward compatibility
	}

	c.ResponseWriter().Header().Set("Content-Type", "application/json")
	c.ResponseWriter().WriteHeader(http.StatusOK)
	_ = json.NewEncoder(c.ResponseWriter()).Encode(response)
}

// HandleSaveRulesConfig handles PUT /system/rules/config
func (h *SystemHandler) HandleSaveRulesConfig(w http.ResponseWriter, r *http.Request) {
	c := webcontext.NewWebContext(w, r)

	// Read request body
	var requestBody map[string]interface{}
	if err := json.NewDecoder(r.Body).Decode(&requestBody); err != nil {
		http.Error(w, fmt.Sprintf("Invalid JSON: %v", err), http.StatusBadRequest)
		return
	}

	// Convert to JSON bytes for unmarshaling
	requestBytes, err := json.Marshal(requestBody)
	if err != nil {
		http.Error(w, fmt.Sprintf("Failed to marshal request: %v", err), http.StatusBadRequest)
		return
	}

	// Unmarshal and validate structure
	rulesConfig, err := archivalRules.UnmarshalRuleConfig(requestBytes)
	if err != nil {
		http.Error(w, fmt.Sprintf("Invalid rules config structure: %v", err), http.StatusBadRequest)
		return
	}

	// Validate each rule
	for i, rule := range rulesConfig.Rules {
		if err := rule.IsValid(); err != nil {
			http.Error(w, fmt.Sprintf("Rule %d is invalid: %v", i, err), http.StatusBadRequest)
			return
		}
	}

	// Save to database
	if err := h.settingsStore.SetRulesConfig(c.Context(), rulesConfig); err != nil {
		http.Error(w, fmt.Sprintf("Failed to save rules config: %v", err), http.StatusInternalServerError)
		return
	}

	c.ResponseWriter().Header().Set("Content-Type", "application/json")
	c.ResponseWriter().WriteHeader(http.StatusOK)
	_ = json.NewEncoder(c.ResponseWriter()).Encode(map[string]string{"message": "Rules config saved successfully"})
}