package views

import (
	"strconv"

	"hearthforge/internal/config"
	"hearthforge/internal/db"
	"hearthforge/internal/gitcmd"
	"hearthforge/internal/highlight"
	"hearthforge/internal/util"

	g "maragu.dev/gomponents"
	. "maragu.dev/gomponents/html"
)

// PatchList renders the patch index with status tabs, label filter and pages.
func PatchList(cfg *config.Config, user *db.SessionUser, repo *db.Repo, patches []db.Patch,
	status string, counts map[string]int, page PageInfo, repoLabels []db.Label,
	selectedLabelIDs []int64, labelsByPatchID map[int64][]db.Label,
) g.Node {
	labelsParam := LabelsQueryParam(selectedLabelIDs)
	tab := func(key, label string) g.Node {
		class := "list-tab"
		if status == key {
			class += " active"
		}
		return A(Href("/"+repo.Name+"/patches?status="+key+labelsParam), Class(class),
			g.Text(label+" "),
			g.If(counts[key] > 0, Span(Class("tab-count"), g.Text(strconv.Itoa(counts[key])))),
		)
	}
	selected := make(map[int64]bool, len(selectedLabelIDs))
	for _, id := range selectedLabelIDs {
		selected[id] = true
	}
	return Layout(Page{Title: "Patches — " + repo.Name, User: user, Cfg: cfg},
		Div(Class("container"),
			RepoHeader(repo),
			RepoNav(cfg, repo, "patches", user),
			Div(Class("list-header"),
				Div(Class("list-header-tabs"),
					tab("open", "Open"),
					tab("merged", "Merged"),
					tab("closed", "Closed"),
				),
				Div(Class("list-header-actions"),
					g.If(len(repoLabels) > 0, Details(Class("label-filter"),
						Summary(Class("btn btn-secondary btn-sm"),
							g.Text("Filter by label"),
							g.If(len(selectedLabelIDs) > 0,
								Span(Class("tab-count"), g.Text(strconv.Itoa(len(selectedLabelIDs))))),
						),
						Div(Class("label-filter-popup"),
							Form(Method("GET"), Action("/"+repo.Name+"/patches"),
								Input(Type("hidden"), Name("status"), Value(status)),
								Div(Class("label-filter-list"),
									g.Map(repoLabels, func(label db.Label) g.Node {
										return Label(Class("label-filter-item"),
											Input(Type("checkbox"), Name("labels"),
												Value(strconv.FormatInt(label.ID, 10)),
												g.If(selected[label.ID], Checked())),
											labelBadge(label),
										)
									}),
								),
								Div(Class("label-filter-actions"),
									Button(Type("submit"), Class("btn btn-primary btn-sm"), g.Text("Apply")),
									A(Href("/"+repo.Name+"/patches?status="+status),
										Class("btn btn-secondary btn-sm"), g.Text("Clear")),
								),
							),
						),
					)),
					g.If(user != nil, A(Href("/"+repo.Name+"/patches/new"),
						Class("btn btn-primary btn-sm"), g.Text("Upload patch"))),
				),
			),
			g.If(len(patches) == 0, Div(Class("empty-state"),
				P(g.Text("No "+status+" patches.")))),
			g.If(len(patches) > 0, Ul(Class("issue-list"),
				g.Map(patches, func(patch db.Patch) g.Node {
					labels := labelsByPatchID[patch.ID]
					return Li(Class("issue-item"),
						Div(Class("issue-main"),
							Span(Class("patch-status-dot "+patch.Status)),
							A(Href("/"+repo.Name+"/patches/"+strconv.FormatInt(patch.Number, 10)),
								Class("issue-title"), g.Text(patch.Title)),
							Span(Class("issue-number"), g.Text("#"+strconv.FormatInt(patch.Number, 10))),
						),
						g.If(len(labels) > 0, Div(Class("issue-labels"),
							g.Map(labels, labelBadge))),
						Div(Class("issue-meta"),
							Avatar(patch.AuthorID, patch.AuthorAvatarVersion, 20),
							Span(g.Text("by "+util.DisplayName(deref(patch.AuthorUsername), cfg.OwnerDisplayName))),
							g.El("time", DateTime(patch.CreatedAt), g.Text(util.FormatDate(patch.CreatedAt))),
						),
					)
				}),
			)),
			Pagination(page),
		),
	)
}

// NewPatch renders the patch upload form.
func NewPatch(cfg *config.Config, user *db.SessionUser, repo *db.Repo, errMsg, template string,
	labels []db.Label,
) g.Node {
	showLabels := len(labels) > 0 && (user.IsAdmin || repo.AllowUserLabels)
	return Layout(Page{Title: "New patch — " + repo.Name, User: user, Cfg: cfg},
		Div(Class("container"),
			RepoHeader(repo),
			RepoNav(cfg, repo, "patches", user),
			H2(Class("section-title"), g.Text("Upload patch")),
			g.If(errMsg != "", P(Class("form-error"), g.Text(errMsg))),
			Form(Method("POST"), Action("/"+repo.Name+"/patches"),
				EncType("multipart/form-data"), Class("form-card"),
				Div(Class("form-group"),
					Label(For("title"), g.Text("Title")),
					Input(ID("title"), Name("title"), Type("text"), Required(),
						MaxLength(strconv.Itoa(cfg.MaxTitleBytes)),
						Placeholder("What does this patch do?")),
				),
				Div(Class("form-group"),
					Label(For("description"), g.Text("Description "),
						Span(Class("text-muted"), g.Text("(Markdown supported, optional)"))),
					Textarea(ID("description"), Name("description"), Rows("5"),
						MaxLength(strconv.Itoa(cfg.MaxTextBodyBytes)), g.Text(template)),
				),
				Div(Class("form-group"),
					Label(For("patch_file"), g.Text("Patch file "),
						Span(Class("text-muted"), g.Text("(.patch)"))),
					Input(ID("patch_file"), Name("patch_file"), Type("file"),
						Accept(".patch"), Required()),
				),
				g.If(showLabels, Div(Class("form-group"),
					Span(Class("form-group-label"), g.Text("Labels")),
					Div(Class("label-checkbox-list"),
						g.Map(labels, func(label db.Label) g.Node {
							return Label(Class("label-checkbox-item"),
								Input(Type("checkbox"), Name("label_ids"),
									Value(strconv.FormatInt(label.ID, 10))),
								labelBadge(label),
							)
						}),
					),
				)),
				Div(Class("form-actions"),
					Button(Type("submit"), Class("btn btn-primary"), g.Text("Upload patch")),
					A(Href("/"+repo.Name+"/patches"), Class("btn"), g.Text("Cancel")),
				),
			),
		),
	)
}

// PatchDetail renders one patch: conversation tab or changes tab.
// applyResult is nil when no apply check ran.
func PatchDetail(cfg *config.Config, user *db.SessionUser, repo *db.Repo, patch *db.Patch,
	descriptionHTML string, applyResult *gitcmd.ApplyResult, files []highlight.RenderedDiffFile,
	tab string, meta gitcmd.PatchMeta, comments []ThreadComment, reactions []ReactionCount,
	commentReactions map[int64][]ReactionCount, patchLabels, repoLabels []db.Label,
) g.Node {
	isAuthor := user != nil && patch.AuthorID != nil && user.ID == *patch.AuthorID
	canEdit := user != nil && (user.IsAdmin || (isAuthor && patch.Status == "open"))
	canManageLabels := user != nil && (user.IsAdmin || (repo.AllowUserLabels && isAuthor))
	isAdmin := user != nil && user.IsAdmin

	baseURL := "/" + repo.Name + "/patches/" + strconv.FormatInt(patch.Number, 10)
	closeLabel := "Reopen patch"
	if patch.Status == "open" {
		closeLabel = "Close patch"
	}

	return Layout(Page{Title: patch.Title + " — " + repo.Name, User: user, Cfg: cfg},
		Div(Class("container"),
			RepoHeader(repo),
			RepoNav(cfg, repo, "patches", user),

			Div(Class("issue-detail"),
				Div(Class("issue-detail-header"),
					Span(Class("issue-number"), g.Text("#"+strconv.FormatInt(patch.Number, 10))),
					EditableTitle(cfg, patch.Title, canEdit, baseURL+"/edit",
						"edit_description", patch.Description),
					Span(Class("patch-badge "+patch.Status), g.Text(patch.Status)),
					g.If(canEdit, Div(Class("issue-detail-meta-actions"),
						g.If(isAdmin && patch.Status == "open" &&
							applyResult != nil && applyResult.Status == "clean",
							Form(Method("POST"), Action(baseURL+"/merge"), Class("inline-form"),
								Input(Type("hidden"), Name("version"), Value(patch.Version)),
								Button(Type("submit"), Class("btn btn-sm btn-primary"),
									g.Text("Merge patch")),
							)),
						g.If(patch.Status == "open", Details(Class("confirm-details"),
							Summary(Class("btn btn-sm"), g.Text("Update patch file")),
							Div(Class("confirm-popup"),
								Form(Method("POST"), Action(baseURL+"/upload"),
									EncType("multipart/form-data"), Class("upload-patch-form"),
									Input(Type("file"), Name("patch_file"), Accept(".patch"),
										Required(), Class("form-input")),
									Button(Type("submit"), Class("btn btn-sm btn-primary"),
										g.Text("Upload")),
								),
							),
						)),
						g.If(isAdmin && patch.Status != "merged",
							Form(Method("POST"), Action(baseURL+"/close"), Class("inline-form"),
								Button(Type("submit"), Class("btn btn-sm"), g.Text(closeLabel)),
							)),
						Details(Class("confirm-details"),
							Summary(Class("btn btn-sm btn-danger"), g.Text("Delete")),
							Div(Class("confirm-popup"),
								g.Text("Permanently delete this patch?"),
								Form(Method("POST"), Action(baseURL+"/delete"), Class("inline-form"),
									Button(Type("submit"), Class("btn btn-sm btn-danger"),
										g.Text("Yes, delete")),
								),
							),
						),
					)),
				),
				LabelBadges(patchLabels, repoLabels, canManageLabels, baseURL),
			),

			Div(Class("patch-tab-nav"),
				A(Href(baseURL), Class(activeTabClass(tab == "conversation")),
					g.Text("Conversation "),
					g.If(len(comments) > 0,
						Span(Class("tab-count"), g.Text(strconv.Itoa(len(comments))))),
				),
				A(Href(baseURL+"?tab=changes"), Class(activeTabClass(tab == "changes")),
					g.Text("Changes "),
					g.If(len(files) > 0,
						Span(Class("tab-count"), g.Text(strconv.Itoa(len(files))))),
				),
			),

			g.If(tab == "conversation", Div(Class("issue-detail"),
				Div(Class("timeline-item"),
					Div(Class("timeline-author"),
						Avatar(patch.AuthorID, patch.AuthorAvatarVersion, 24),
						Strong(g.Text(util.DisplayName(deref(patch.AuthorUsername), cfg.OwnerDisplayName))),
						Div(Class("timeline-author-right"),
							g.If(canEdit, Details(Class("inline-edit-details"),
								Summary(Class("btn btn-xs"),
									Span(Class("when-closed"), g.Text("Edit")),
									Span(Class("when-open"), g.Text("Stop editing")),
								),
							)),
							DateWithEdited(patch.CreatedAt, patch.EditedAt),
						),
					),
					g.If(canEdit, Div(Class("inline-edit-form-area"),
						Form(Method("POST"), Action(baseURL+"/edit"), Class("inline-edit-form"),
							Input(Type("hidden"), Name("title"), Value(patch.Title)),
							Div(Class("form-group"),
								Textarea(Class("form-input"), ID("edit-patch-desc"),
									Name("edit_description"), Rows("6"),
									MaxLength(strconv.Itoa(cfg.MaxTextBodyBytes)),
									g.Text(patch.Description)),
							),
							Div(Class("form-actions"),
								Button(Type("submit"), Class("btn btn-sm btn-primary"), g.Text("Save")),
							),
						),
					)),
					// The markdown renderer already sanitised this HTML.
					Div(Class("timeline-body markdown-body"),
						g.If(descriptionHTML != "", g.Raw(descriptionHTML)),
						g.If(descriptionHTML == "",
							Em(Class("text-muted"), g.Text("No description provided."))),
					),
					ReactionBar(reactions, baseURL+"/react", 0, user),
				),

				g.Iff(applyResult != nil, func() g.Node { return applyStatus(applyResult) }),

				CommentThread(cfg, user, comments, commentReactions, baseURL, patch.Status),
			)),

			g.If(tab == "changes", Div(
				Div(Class("commit-card"),
					H2(Class(commitSubjectClass(meta.Subject)), g.Text(commitSubject(meta.Subject))),
					g.If(meta.Body != "", Pre(Class("commit-card-body"), g.Text(meta.Body))),
					Div(Class("commit-card-meta"),
						Div(Class("commit-card-meta-row"),
							Span(Class("commit-meta-label"), g.Text("Author")),
							Span(Class("commit-meta-value"), g.Text(meta.Author+" <"+meta.Email+">")),
						),
						Div(Class("commit-card-meta-row"),
							Span(Class("commit-meta-label"), g.Text("Date")),
							g.El("time", Class("commit-meta-value"), DateTime(meta.Date),
								g.Text(util.FormatDateTime(meta.Date))),
						),
					),
				),
				DiffView(files, repo, ""),
			)),
		),
	)
}

// applyStatus renders the "applies cleanly" or "has conflicts" banner.
func applyStatus(result *gitcmd.ApplyResult) g.Node {
	icon, text := "✗", "Has conflicts"
	if result.Status == "clean" {
		icon, text = "✓", "Applies cleanly"
	}
	return Div(Class("timeline-item"),
		Div(Class("apply-result apply-"+result.Status),
			Div(
				Span(Class("apply-icon"), g.Text(icon)),
				Span(g.Text(text)),
			),
			g.If(result.Output != "", Pre(Class("apply-output"), g.Text(result.Output))),
		),
	)
}

func activeTabClass(active bool) string {
	if active {
		return "repo-tab active"
	}
	return "repo-tab"
}

func commitSubjectClass(subject string) string {
	if subject == "" {
		return "commit-card-subject commit-card-subject-empty"
	}
	return "commit-card-subject"
}

func commitSubject(subject string) string {
	if subject == "" {
		return "No commit message"
	}
	return subject
}