// backend\tasks_status.go

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"strings"
	"sync"
	"sync/atomic"
	"time"
)

type CleanupTaskState struct {
	ID          string     `json:"id"`
	Queued      bool       `json:"queued"`
	Running     bool       `json:"running"`
	QueuedAt    time.Time  `json:"queuedAt"`
	StartedAt   time.Time  `json:"startedAt"`
	FinishedAt  *time.Time `json:"finishedAt,omitempty"`
	Text        string     `json:"text,omitempty"`
	Error       string     `json:"error,omitempty"`
	CurrentFile string     `json:"currentFile,omitempty"`
	Done        int        `json:"done"`
	Total       int        `json:"total"`
}

type CheckVideosTaskState struct {
	ID          string     `json:"id"`
	Queued      bool       `json:"queued"`
	Running     bool       `json:"running"`
	QueuedAt    time.Time  `json:"queuedAt"`
	StartedAt   time.Time  `json:"startedAt"`
	FinishedAt  *time.Time `json:"finishedAt,omitempty"`
	Text        string     `json:"text,omitempty"`
	Error       string     `json:"error,omitempty"`
	CurrentFile string     `json:"currentFile,omitempty"`
	Done        int        `json:"done"`
	Total       int        `json:"total"`
}

type RegenerateAssetsTaskState struct {
	Running bool   `json:"running"`
	File    string `json:"file,omitempty"`
	Text    string `json:"text,omitempty"`
	Error   string `json:"error,omitempty"`
}

type TasksStatusResponse struct {
	GenerateAssetsJobs   []AssetsTaskState      `json:"generateAssetsJobs"`
	RegenerateAssetsJobs []map[string]any       `json:"regenerateAssetsJobs"`
	CheckVideosJobs      []CheckVideosTaskState `json:"checkVideosJobs"`
	CleanupJobs          []CleanupTaskState     `json:"cleanupJobs"`
	AnyRunning           bool                   `json:"anyRunning"`
}

var (
	cleanupTaskMu    sync.Mutex
	cleanupTaskState CleanupTaskState

	regenerateAssetsTaskMu    sync.Mutex
	regenerateAssetsTaskState RegenerateAssetsTaskState
)

var nextTaskID atomic.Uint64

func newTaskID(prefix string) string {
	n := nextTaskID.Add(1)
	return fmt.Sprintf("%s-%d-%d", prefix, time.Now().UnixNano(), n)
}

func cleanupNowTime() *time.Time {
	t := time.Now()
	return &t
}

func anyToString(v any) string {
	switch x := v.(type) {
	case string:
		return x
	case []byte:
		return string(x)
	default:
		return ""
	}
}

func snapshotRegenerateAssetsTaskState() RegenerateAssetsTaskState {
	regenerateAssetsTaskMu.Lock()
	st := regenerateAssetsTaskState
	regenerateAssetsTaskMu.Unlock()
	return st
}

func setRegenerateAssetsTaskRunning(file, text string) {
	regenerateAssetsTaskMu.Lock()
	regenerateAssetsTaskState = RegenerateAssetsTaskState{
		Running: true,
		File:    strings.TrimSpace(file),
		Text:    strings.TrimSpace(text),
		Error:   "",
	}
	regenerateAssetsTaskMu.Unlock()

	publishTaskState()
}

func setRegenerateAssetsTaskDone(file, text string) {
	regenerateAssetsTaskMu.Lock()
	regenerateAssetsTaskState = RegenerateAssetsTaskState{
		Running: false,
		File:    strings.TrimSpace(file),
		Text:    strings.TrimSpace(text),
		Error:   "",
	}
	regenerateAssetsTaskMu.Unlock()

	publishTaskState()
}

func setRegenerateAssetsTaskError(file, errText string) {
	regenerateAssetsTaskMu.Lock()
	regenerateAssetsTaskState = RegenerateAssetsTaskState{
		Running: false,
		File:    strings.TrimSpace(file),
		Text:    "",
		Error:   strings.TrimSpace(errText),
	}
	regenerateAssetsTaskMu.Unlock()

	publishTaskState()
}

func clearRegenerateAssetsTaskState() {
	regenerateAssetsTaskMu.Lock()
	regenerateAssetsTaskState = RegenerateAssetsTaskState{}
	regenerateAssetsTaskMu.Unlock()

	publishTaskState()
}

func snapshotCleanupTaskState() CleanupTaskState {
	cleanupTaskMu.Lock()
	st := cleanupTaskState
	cleanupTaskMu.Unlock()
	return st
}

func setCleanupTaskQueued(text string) {
	cleanupTaskMu.Lock()
	cleanupTaskState = CleanupTaskState{
		Queued:      true,
		Running:     false,
		QueuedAt:    time.Now(),
		StartedAt:   time.Time{},
		FinishedAt:  nil,
		Text:        strings.TrimSpace(text),
		Error:       "",
		CurrentFile: "",
		Done:        0,
		Total:       0,
	}
	cleanupTaskMu.Unlock()

	publishTaskState()
}

func setCleanupTaskRunning(text string) {
	cleanupTaskMu.Lock()

	now := time.Now()
	queuedAt := cleanupTaskState.QueuedAt
	if queuedAt.IsZero() {
		queuedAt = now
	}

	cleanupTaskState = CleanupTaskState{
		Queued:      false,
		Running:     true,
		QueuedAt:    queuedAt,
		StartedAt:   now,
		FinishedAt:  nil,
		Text:        strings.TrimSpace(text),
		Error:       "",
		CurrentFile: "",
		Done:        0,
		Total:       0,
	}
	cleanupTaskMu.Unlock()

	publishTaskState()
}

func setCleanupTaskProgress(done, total int, currentFile, text string) {
	cleanupTaskMu.Lock()

	now := time.Now()
	if cleanupTaskState.QueuedAt.IsZero() {
		cleanupTaskState.QueuedAt = now
	}
	if cleanupTaskState.StartedAt.IsZero() {
		cleanupTaskState.StartedAt = now
	}

	cleanupTaskState.Queued = false
	cleanupTaskState.Running = true
	cleanupTaskState.Done = done
	cleanupTaskState.Total = total
	cleanupTaskState.CurrentFile = strings.TrimSpace(currentFile)
	cleanupTaskState.Text = strings.TrimSpace(text)
	cleanupTaskState.Error = ""
	cleanupTaskState.FinishedAt = nil

	cleanupTaskMu.Unlock()

	publishTaskState()
}

func setCleanupTaskDone(text string) {
	cleanupTaskMu.Lock()

	cleanupTaskState.Queued = false
	cleanupTaskState.Running = false
	cleanupTaskState.Text = strings.TrimSpace(text)
	cleanupTaskState.CurrentFile = ""
	cleanupTaskState.Error = ""
	cleanupTaskState.FinishedAt = cleanupNowTime()

	if cleanupTaskState.Total > 0 {
		cleanupTaskState.Done = cleanupTaskState.Total
	}

	cleanupTaskMu.Unlock()

	publishTaskState()
}

func setCleanupTaskError(errText string) {
	cleanupTaskMu.Lock()

	cleanupTaskState.Queued = false
	cleanupTaskState.Running = false
	cleanupTaskState.Text = ""
	cleanupTaskState.Error = strings.TrimSpace(errText)
	cleanupTaskState.CurrentFile = ""
	cleanupTaskState.FinishedAt = cleanupNowTime()

	cleanupTaskMu.Unlock()

	publishTaskState()
}

func tasksStatusHandler(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "Nur GET erlaubt", http.StatusMethodNotAllowed)
		return
	}

	assetsJobs := snapshotAssetsJobs()
	regenerateJobs := getRegenerateAssetsJobsSnapshot()
	checkVideosJobs := snapshotCheckVideosJobs()
	cleanupJobs := snapshotCleanupJobs()

	anyRunning := false

	if !anyRunning {
		for _, st := range assetsJobs {
			if st.Queued || st.Running {
				anyRunning = true
				break
			}
		}
	}

	if !anyRunning {
		for _, st := range checkVideosJobs {
			if st.Queued || st.Running {
				anyRunning = true
				break
			}
		}
	}

	if !anyRunning {
		for _, st := range cleanupJobs {
			if st.Queued || st.Running {
				anyRunning = true
				break
			}
		}
	}

	if !anyRunning {
		for _, job := range regenerateJobs {
			state := strings.TrimSpace(strings.ToLower(anyToString(job["state"])))
			if state == "queued" || state == "running" {
				anyRunning = true
				break
			}
		}
	}

	resp := TasksStatusResponse{
		GenerateAssetsJobs:   assetsJobs,
		RegenerateAssetsJobs: regenerateJobs,
		CheckVideosJobs:      checkVideosJobs,
		CleanupJobs:          cleanupJobs,
		AnyRunning:           anyRunning,
	}

	w.Header().Set("Content-Type", "application/json")
	w.Header().Set("Cache-Control", "no-store")
	_ = json.NewEncoder(w).Encode(resp)
}