package `in`.caresoft.sahi

import android.app.Activity
import android.content.Intent
import android.os.Bundle
import android.view.View
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.lifecycle.lifecycleScope
import `in`.caresoft.sahi.databinding.ActivityProcessTextBinding
import kotlinx.coroutines.launch

/**
 * The path that needs no keyboard.
 *
 * Select text anywhere on the phone — WhatsApp, Gmail, Chrome, the HIS web app —
 * and tap Sahi in the selection toolbar. Android hands over the selection and
 * takes back the corrected version. It cannot see anything else you type,
 * which is the whole reason to prefer it.
 *
 * Read-only callers (some apps offer the action on text you cannot edit) get
 * the corrected version to copy instead.
 */
class ProcessTextActivity : AppCompatActivity() {

    private lateinit var ui: ActivityProcessTextBinding
    private var original: String = ""
    private var corrected: String = ""
    private var issues: List<Issue> = emptyList()
    private var readOnly = false

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        ui = ActivityProcessTextBinding.inflate(layoutInflater)
        setContentView(ui.root)

        original = extractText().orEmpty()
        readOnly = intent.getBooleanExtra(Intent.EXTRA_PROCESS_TEXT_READONLY, false) ||
            intent.action == Intent.ACTION_SEND

        if (original.isBlank()) {
            finishWith("Select some text first.")
            return
        }
        if (!Prefs.isConfigured) {
            startActivity(Intent(this, SettingsActivity::class.java))
            finishWith("Enter your server address and key to get started.")
            return
        }

        ui.originalText.text = original
        ui.applyButton.setOnClickListener { applyAndReturn() }
        ui.copyButton.setOnClickListener { copyToClipboard() }
        ui.rewriteButton.setOnClickListener { showRewriteMenu() }

        check()
    }

    private fun extractText(): CharSequence? = when (intent.action) {
        Intent.ACTION_PROCESS_TEXT -> intent.getCharSequenceExtra(Intent.EXTRA_PROCESS_TEXT)
        Intent.ACTION_SEND -> intent.getCharSequenceExtra(Intent.EXTRA_TEXT)
        else -> null
    }

    private fun check() {
        setBusy(true, getString(R.string.checking))
        lifecycleScope.launch {
            try {
                issues = SahiApi.check(original)
                corrected = SahiApi.applyAll(original, issues)
                render()
            } catch (e: Exception) {
                setBusy(false, e.message ?: getString(R.string.something_went_wrong))
            }
        }
    }

    private fun render() {
        setBusy(false, null)

        if (issues.isEmpty()) {
            ui.status.text = getString(R.string.nothing_to_change)
            ui.correctedText.visibility = View.GONE
            ui.issueList.visibility = View.GONE
            ui.applyButton.visibility = View.GONE
            return
        }

        ui.status.text = resources.getQuantityString(R.plurals.corrections, issues.size, issues.size)
        ui.correctedText.text = corrected
        ui.correctedText.visibility = View.VISIBLE
        ui.applyButton.visibility = if (readOnly) View.GONE else View.VISIBLE

        // A plain list of what changed. On a phone this reads better than trying
        // to paint underlines onto text the user cannot edit here anyway.
        ui.issueList.text = issues.joinToString("\n") { issue ->
            "· ${issue.original} → ${issue.replacement}"
        }
        ui.issueList.visibility = View.VISIBLE
    }

    private fun showRewriteMenu() {
        val labels = resources.getStringArray(R.array.rewrite_labels)
        val modes = resources.getStringArray(R.array.rewrite_modes)

        androidx.appcompat.app.AlertDialog.Builder(this)
            .setTitle(R.string.rewrite)
            .setItems(labels) { _, which -> rewrite(modes[which]) }
            .show()
    }

    private fun rewrite(mode: String) {
        setBusy(true, getString(R.string.rewriting))
        lifecycleScope.launch {
            try {
                corrected = SahiApi.rewrite(original, mode)
                issues = emptyList()
                setBusy(false, getString(R.string.rewritten))
                ui.correctedText.text = corrected
                ui.correctedText.visibility = View.VISIBLE
                ui.issueList.visibility = View.GONE
                ui.applyButton.visibility = if (readOnly) View.GONE else View.VISIBLE
            } catch (e: Exception) {
                setBusy(false, e.message ?: getString(R.string.something_went_wrong))
            }
        }
    }

    private fun applyAndReturn() {
        if (corrected.isEmpty()) return

        lifecycleScope.launch {
            issues.forEach { SahiApi.report("accepted", it) }
        }

        // Returning the text is what makes the host app replace the selection.
        setResult(
            Activity.RESULT_OK,
            Intent().putExtra(Intent.EXTRA_PROCESS_TEXT, corrected)
        )
        finish()
    }

    private fun copyToClipboard() {
        val text = corrected.ifEmpty { original }
        val clipboard = getSystemService(CLIPBOARD_SERVICE) as android.content.ClipboardManager
        clipboard.setPrimaryClip(android.content.ClipData.newPlainText("Sahi", text))
        Toast.makeText(this, R.string.copied, Toast.LENGTH_SHORT).show()
    }

    private fun setBusy(busy: Boolean, message: String?) {
        ui.progress.visibility = if (busy) View.VISIBLE else View.GONE
        ui.rewriteButton.isEnabled = !busy
        ui.applyButton.isEnabled = !busy
        message?.let { ui.status.text = it }
    }

    private fun finishWith(message: String) {
        Toast.makeText(this, message, Toast.LENGTH_LONG).show()
        finish()
    }
}