export type Tool = 'claude-code' | 'opencode' | 'crush' | 'pi' | 'kimi' | string
export type Host = 'laptop' | 'workpc' | string

export interface SessionDTO {
  owner: string
  tool: string
  host: string
  session_id: string
  started_at: number     // unix epoch seconds
  ended_at: number
  working_dir?: string
  source_file: string
  summary: string
  turn_count: number
  tokens_in_total: number
  tokens_out_total: number
  model?: string
  metadata?: unknown
}

export interface Session {
  id: string             // `${tool}/${host}/${session_id}`
  tool: string
  host: string
  cwd: string            // working_dir ?? ''
  model?: string
  started: string        // ISO 8601
  ended: string | null   // null if ended_at <= started_at
  summary: string
  turns: number
  tokensIn: number
  tokensOut: number
  hasError: boolean      // TODO: always false until error tracking is implemented
}

export function adaptSession(d: SessionDTO): Session {
  return {
    id: `${d.tool}/${d.host}/${d.session_id}`,
    tool: d.tool,
    host: d.host,
    cwd: d.working_dir ?? '',
    model: d.model,
    started: new Date(d.started_at * 1000).toISOString(),
    ended: d.ended_at > d.started_at ? new Date(d.ended_at * 1000).toISOString() : null,
    summary: d.summary,
    turns: d.turn_count,
    tokensIn: d.tokens_in_total,
    tokensOut: d.tokens_out_total,
    hasError: false,
  }
}

// ── Projects ─────────────────────────────────────────────────────────────────

export interface ProjectDTO {
  cwd: string
  sessions: number
  turn_count: number
  tokens_in_total: number
  tokens_out_total: number
  last_active: number   // unix epoch seconds; 0 = never
  hosts: string[]
  tools: string[]
  top_tool: string
}

export interface Project {
  cwd: string
  sessions: number
  turns: number
  tokensIn: number
  tokensOut: number
  lastActive: string    // ISO 8601, or '' when last_active === 0
  hosts: string[]
  tools: string[]
  topTool: string
}

export function adaptProject(d: ProjectDTO): Project {
  return {
    cwd: d.cwd,
    sessions: d.sessions,
    turns: d.turn_count,
    tokensIn: d.tokens_in_total,
    tokensOut: d.tokens_out_total,
    lastActive: d.last_active === 0 ? '' : new Date(d.last_active * 1000).toISOString(),
    hosts: d.hosts,
    tools: d.tools,
    topTool: d.top_tool,
  }
}

// ── Stats ─────────────────────────────────────────────────────────────────────

export interface ToolRollupDTO {
  tool: string
  sessions: number
  turns: number
  tokens_in: number
  tokens_out: number
  daily_sparkline: number[]
}

export interface DailyBucketDTO {
  date_unix: number
  per_tool: Record<string, number>
}

export interface HeatmapCellDTO {
  date_unix: number
  count: number
}

export interface CwdRowDTO {
  cwd: string
  count: number
}

export interface HourBucketDTO {
  hour: number
  count: number
}

export interface HostRowDTO {
  host: string
  count: number
}

export interface StatsDTO {
  per_tool: ToolRollupDTO[]
  daily: DailyBucketDTO[]
  heatmap: HeatmapCellDTO[]
  top_cwd: CwdRowDTO[]
  hour_of_day: HourBucketDTO[]
  host_split: HostRowDTO[]
}

export interface ToolRollup {
  tool: string
  sessions: number
  turns: number
  tokensIn: number
  tokensOut: number
  dailySparkline: number[]
}

export interface DailyBucket {
  date: string             // ISO 8601
  perTool: Record<string, number>
}

export interface HeatmapCell {
  date: string             // ISO 8601
  count: number
}

export interface CwdRow {
  cwd: string
  count: number
}

export interface HourBucket {
  hour: number
  count: number
}

export interface HostRow {
  host: string
  count: number
}

export interface Stats {
  perTool: ToolRollup[]
  daily: DailyBucket[]
  heatmap: HeatmapCell[]
  topCwd: CwdRow[]
  hourOfDay: HourBucket[]
  hostSplit: HostRow[]
}

export function adaptStats(d: StatsDTO): Stats {
  return {
    perTool: d.per_tool.map(r => ({
      tool: r.tool,
      sessions: r.sessions,
      turns: r.turns,
      tokensIn: r.tokens_in,
      tokensOut: r.tokens_out,
      dailySparkline: r.daily_sparkline,
    })),
    daily: d.daily.map(b => ({
      date: new Date(b.date_unix * 1000).toISOString(),
      perTool: b.per_tool,
    })),
    heatmap: d.heatmap.map(c => ({
      date: new Date(c.date_unix * 1000).toISOString(),
      count: c.count,
    })),
    topCwd: d.top_cwd,
    hourOfDay: d.hour_of_day,
    hostSplit: d.host_split,
  }
}